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Scanned from the collections of The Library of Congress
AUDIO-VISUAL CONSERVATION at The LIBRARY jf CONGRESS
'*"?"
Packard Campus
for Audio Visual Conservation
www.loc.gov/avconservation
Motion Picture and Television Reading Room www.loc.gov/rr/mopic
Recorded Sound Reference Center www.loc.gov/rr/record
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Motion Picture
R0JECTI0N1ST
ar of
lie (it ion )
\^HETHER you run sound-on-film or sound-
on-disc, the Ilex Dual Focus Lens retains
the same size screen covering and the same
clean-cut brilliant pictures (or either type of film.
y\ SHIFT of the lever adapts it for any type of film and brings the picture into sharp focus in either position.
^HEN order- ing give make of projec- tion machine, size of screen and length of throw from projector to screen.
L%-
C'
&\
ILEX OPTICAL COMPANY
ROCHESTER NEW YORK
ESTABLISHED 1910
A MANCALL PUBLICATION
IBHBB9
N*. 1 25c, per cep? $2.06 per year
Now Ready!
Kaplan Rear Shutter
Can be Attached to Any Sure-Fit or Simplex Mechanism
See your local dealer or write to us
Sam Kaplan Manufacturing and Supply Company, Inc.
729 Seventh Avenue New York City
November, 1930
Motion Picture Projectionist
2^L3J-
QUIET OPERATION
2 OVER LOAD CAPACITY
-4 RELIABILITY
3
CONSTANT VOLTAGE
for Small Theatres
for Large Theatres
OUR
BUSINESS
CREED
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COURTEOUS TFtEATTMErST
Never before has the public been as "picture" con- scious as they are today. This applies to Quality of Projection as well as to type of picture.
Imperial Motor Generator sets are especially de- signed for Projection work and have built into them features that enable you to obtain the type of Pro- jection necessary to satisfy a discriminating and "picture" conscious audience.
Consult Your Dealer or Write Us.
THE IMPERIAL ELECTRIC CO.
AKRON
Established 1889 Branches in Principal Cities
OHIO
Motion Picture Projectionist
November, 1930
WORLD'S BEST THEATRE EQUIPMENT
Tomorrow's Proj ector
is here Today!
JL wo years ago Fulco was brought to the showmen of the world.
X oday it stands established as the most efficient picture machine the world has produced.
1 omorrow it will dominate even more completely. Why? The record answers that question. And here's the record.
JJ ulco, costing no more for initial outlay, costs less to maintain. Automatic lubrication, oversize working parts, dust-tight housing, reduce friction and wear.
J; ulco, designed for the age of improved projection, gives better screen results — steadier picture and better sound, because it can't vibrate and won't develop noise.
_F ulco, built to carry moist air cooling at aperture, permits use of increasing light intensities necessary for the show effects of the future.
JP ulco, providing accessibility of working parts and instant replacement of intermittent, sprocket, and tension shoes, insures the life of your show.
V/nly by comparison — point by point — with other projectors is Fulco's superiority fully revealed.
J.f you are fed up with paying out box office profits for repair and replacement-parts bills on machines of antiquated design, for the sake of your bank roll and your reputation as a showman make this comparison.
J. here is no obligation in calling on our representative for a demonstration.
FULCO PROJECTOR
(Ernemann Design)
On demonstration at all E. E. Fulton Company branch offices located in the following cities:
CHICAGO 1018 So. Wabash Ave.
NEW YORK 115 W. 45th St.
BOSTON '. 65 Broadway
PHILADELPHIA 1337 Vine St.
ATLANTA 146 Walton St.
LOS ANGELES . . . .Film Exchange Bldg.
ST. LOUIS 3232 Olive St.
MILWAUKEE 151 Seventh St.
INDIANAPOLIS 340 No. Illinois St.
SAN FRANCISCO ...255 Golden Gate Ave.
E. E. FULTON COMPANY
C. H. FULTON
President
A. G. JARMIN
Treasurer
Executive Offices: 1018 So. Wabash Ave., Chicago Factory: 2001 So. California Ave., Chicago
OULC05
E. E. FULTON COMPANY, Coast to Coast Distributors
November, 1930
Motion Picture Projectionist
MOTION PICTURE PROJECTIONIST
November, 1930 Vol. 4, No. 1
JAMES J. FINN, Editor
Lester Isaac, Efficiency; J. H. Kurlander, Light; Arthur Gray, Conservation; John Kieley, Equipment; Samuel Wein, Re- search; R. H. McCullough, Sound Pro- jection; Harry Rubin, Improvement; Victor Welman, Personnel; Sidney Bur- ton, Production.
Published monthly by Mancall Publish- ing Corp., 45 West 45th St., New York City. Subscription rates in U. S. and Canada: twenty-five cents per copy; two dollars per year; three dollars for two years. Add one dollar for foreign post- age. Changes of address should be sub- mitted three weeks in advance of publi- cation date to insure receipt of current issue.
Entered as second class matter Oct. 25, 1927, at Post Office, New York, N. Y., under the act of March 3, 1879.
Canadian Representative
H. N. Elliott, Suite 11, 27 Sherwood Ave.,
Toronto, Canada.
Australian Representative
McGill's Agency
179 and 218 Elizabeth St.
Melbourne, Australia
Editorial & Advertising Office
45 West 45th St.
New York City
65 mm. Film Size Desirable^ Says Publix Technician
Dr. N. M. La Porte, director of re- search for Paramount-Publix, recent- ly had some interesting things to say relative to the advantages of using 65 mm. film. Dr. La Porte pointed out that 65 mm. film not only sup- plies an increased angle of vision but greatly increases the sharpness of the picture.
He also explained that the installa- tion of wide screens in several of the Paramount-Publix houses had noth- ing to do with the advancement of wide film photography, although when wide film productions are released the screens could probably be used for that as well as their present use in relation to the Magnascope. In re- spect to recent experiments with 65 mm. film Dr. La Porte made the fol- lowing statement:
Condemns Excessive Magnification "In the use of 35 mm. film on an average 24-foot screen, the magni- fication of the picture is approxi- mately 90,000 to 1. In using the 65 mm. film that we are experimenting
Make them go out with a smile
National Projector Carbons burning in your machines will insure a clear, steady light on the screen with no flicker! Pictures that are easy on the eyes will be espe- cially appreciated. Your customers will leave your theater with a smile of contentment. Because National Projector Carbons are controlled and inspected in all stages of manufacture, you can be certain of smooth per- formance . . . even-burning on increased amperage . . . more light per watt. National Projector Carbons help insure steady patronage by giving your audience the best of every film.
NATIONAL CARBON CO., Inc. Carbon Sales Division: Cleveland, Ohio
BRANCH SALES OFFICES New York, N. Y. Pittsburgh, Pa. Chicago, 111. Birmingham, Ala. San Francisco, Cal.
Unit of Union Carbide
and Carbon Corporation
National Projector Carbons
"BEST"
Magazine Light
Price $3.50 at your dealers
attaches to side of magazine illuminating the inside show- ing the exact amount of film on reel from either side with- out opening door.
BEST DEVICES CO.
200 FILM BLDG., CLEVELAND, O.
Motion Picture Projectionist
November, 1930
AUTOMATIC REFLECTOR ARC LAMPS
Silently, Automatically
Producing — Crisp
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FOR SALE BY INDEPENDENT SUPPLY DEALERS
C!he Strong Electric Corporation
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Type V58-A
Concerning
PHOTOELECTRIC CELLS
Higher sensitivity means Lower fader setting
Lower fader setting means Less background noise
Less background noise means Better sound
Better sound means More business
Put VISITRON cells in your machines and watch this work out for you.
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1803 GRACE ST. CHICAGO, ILL.
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with on the screen, it will not be en- larged proportionately, but will be held at a maximum of 42 feet, there- by decreasing the magnification to 65,000 to 1. In reducing the magni- fication the emulsion granules on the film will be invisible and this, plus the concentrated light values impart- ed to and reflected by a screen pro- portionately smaller, even if larger in feet and inches, will enhance the clarity and smoothness of the picture. "The failure of the attempts to magnify 35 mm. film, intended for a 24-foot screen, to a 42-foot picture may be ascribed to the unnaturally magnified picture and the resultant visibility of the granules which gives "fuzziness" to the picture. Another advantage of our 65 mm. film is the greater depth attainable due to the larger field of white, gray, and black color planes that may be contrasted. It is a recognized scientific fact that real third dimensional photography is an impossibility, although a pseudo- third dimensional effect is reached by contrasting light planes through the use of stage lighting. With the im- proved sharpness of 65 mm. film this effect is naturally heightened."
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Another Wide Film Process by Coast Technicians
Development of a wide screen pro- cess using standard 35 mm. film and making it unnecessary for the in- dustry to invest about $250,000,000 in new apparatus, plus some $10,000,- 000 yearly on release prints, has been completed by Gilbert Warrenton, prominent Hollywood cameraman, in association with C. Roy Hunter, su- perintendent of the Universal labora- tory.
Advantages of the new method, be- sides the saving in equipment and prints, are cited as: (1) no change of apparatus needed beyond the reduced aperture-plates used in cameras and projectors, (2) every artistic and technical advantage claimed for wide film is gained, while the optical and production superiority of 35 mm. film is preserved, (3) by use of the bi- pack color processes, wide screen natural color is immediately avail- able, and (4) it is applicable at once to production conditions.
The process calls for the production of a picture of 3 x 6 proportion on standard 35 mm. film, but at all times keeping the main story-telling action in the center of the screen in a 3 x 4 proportion. By doing this it is possible at any time to make an en- larged picture standard size and pro- portion from this negative without making any other change. Insofar as the photographic apparatus is con- cerned, the only change required is the substitution of an aperture of reduced height — .360 inch instead of the present standard of .720 inch. When the standard sound track is used, this gives a picture-proportion of 3 x 6.
November, 1930
Motion Picture Projectionist
The Changeover Adopted as Standard Equipment
1. Armature ( Female )
2. Armature (Male)
3. Closing coil
4. Opening coil
5. Housing
6. Armature Sleeve (Female)
7. Armature Sleeve (Male)
8. Bell-crank
9. Nameplate
10. Mounting bracket
11. Shutter spring
12. Shutter
Model D for GRANDEUR, SUPER-SIMPLEX, SIMPLEX, SURE-FIT.
WITH OR WITHOUT REAR SHUTTER MOUNT
Model B for MOTIOGRAPH F
" THIDE "
AUTOMATIC SHUTTER CONTROL
with
3-WIRE CIRCUIT FOOT SWITCH
Simplicity for mounting — Properly positioned —
Adoption of the new REAR SHUTTER mount necessitates a change in design for mounting the changeover.
Electrically efficient — Mechanically proficient
Your (MODEL A.) changeover will be re- placed with the new (MODEL D.) with a lib- eral allowance for the (MODEL A.) Type.
In use by Roxy, Loew, R-K-O, Fox, Warner, Publix, Wilmer & Vincent and others.
Your Dealer or Write
DOWSER MANUFACTURING CORP.
691 Lincoln Place
Brooklyn, N. Y.
8
Motion Picture Projectionist
WE STONmo^/
547
^7or
IMPROVED SOUND REPRODUCTION
'T'ODAY the projectionist must meet the demand for improved quality in sound reproduction. Only by periodic tests of the sound equipment can this be achieved. Tubes, amplifiers, horns, batteries, and circuits must be checked at regular intervals to assure continuous and satisfactory performance.
Weston Model 547 is ideally suited for this type of work. It has the refinements in design, the ac- curacy and dependability in operation, which have caused engineers and maintenance men in all branches of industry to acknowledge Weston instru- ments as the standard quality in electrical measure- ment.
Model 547 is a compact, light, portable instrument contained in a rugged Bakelite case with a removable cover. It is convenient, fast, simple and reliable in operation, and tests all types of sound equipment.
This Sound Equipment Test Set has three Weston instruments connected through a system of switches and binding posts so arranged that all required measurements are automatically and quickly obtained on the proper instrument scale without making in- dividual connections.
Weston Model 547 is the modern test set for servic- ing sound equipment wherever quality reproduction is demanded.
— Write for descriptive, illustrated folder —
November, 1930
-Just like that
Quicker than the blink of an eye — the NEW SUPER
STRONG CHANGE- OVER DEVICE snaps into its job. No noise — no effort — no mis- cues — merely step on the treadle type foot- switch and quick as a flash there's an in- stantaneous noiseless fade-out and fade-in from one projector to the other.
The New Super is the latest newcomer to the famous Strong family of changeovers — developed for use on the new rear-shutter projectors — Simplex, Motiograph, R. C. A. and others. It con- tains the same mechan- ism as the famous 'FIVE POINT" — which is in reality five distinc- tive devices in one — changeover, eyeshield, framing light, film gate opener and fire gate finger. THE COILS CAN'T BURN OUT.
// your projectors are not equipped with STRONG changeover devices — they should be!
The SUPER Changeover
The STRONG Footswitch
Weston Electrical Instrument Corporation 617 Frelinghuysen Ave. Newark, N. J.
^&r
Ask your nearest supply dealer or write to LARRY STRONG of the
ESSANAY ELECTRIC MANUFACTURING CO.
2809 W. VAN BUREN ST.— CHICAGO, ILL.
November, 1930
Motion Picture Projectionist
An Advertisement Every
•^ — — — «- ■■■■ ■■■■»■■- ■■■■■■■■ «^ >— i -aa
Serious Projectionist Should Read With Care
JL ELEVISION is just around the corner.
Without question Television is one of the greatest achievements of the human mind; it is also one of the greatest forces for human progress. Like the great inventions that preceded it — the telegraph, the telephone, and radio — it will annihilate space, and make it as inconsequential as a city block.
Ten years ago Television was a faint glimmer which our scientific men discerned in a shadowy world of possibilities. The application of their genius and in- dustry has today made television a fact. People already are able to see each other, although thirty miles apart. The further refinement of the instru- ments already developed will shortly make the thirty into three thousand, then thirty thousand miles until we, in New York, will be able to see instantaneously others at the extreme farther side of the world.
Industry, of course, will turn Television to its man- ifold uses at once, as it has done with all inventions. Can it be used for recreational, for entertainment purposes also?
Of course it can — and it will! The great business and industrial institutions of this and other countries that are now backing the development of Television will immediately apply it to the theatre. Millions of homes will be equipped with Television receiving sets, as they now are with radio, and the motion picture theatre will harness it for its own use.
Right now there is a great deal of speculation concerning the nature of the kinship between Tele- vision and the motion picture theatre. Some say that it may do away with the theatre — that everything the theatre offers today, music, photoplays, dancing, chorus girls, singing opera stars, musical comedies, — will come straight into the home by means of radio, and Television. Others declare that it will do away with photoplay production — that the story will be acted out before the Televisor and broadcast imme- diately into the homes and motion picture theatres. Still others — and there are eminent authorities of the theatre and scientific world among these — state that nothing will be changed, that Television will simply help the theatre to further amuse its patrons, just as sound pictures have done. It will not hurt the theatre, but help it.
There is no doubt whatsoever that the motion pic- ture theatre will continue to exist — and will turn Television to its own uses. Roxy, master showman of all time, has declared publicly that he is waiting impatiently for the perfection of Television, that he will at once harness it to his showmanship genius and apply it in the Roxy Theatre. Other magnates are even today making provision for Television equip- ment in their new movie hippodromes.
THOMAS J. BENSON
There has been talk already of the exact application of Television to the theatres. Dr. Lee De Forest, a man of science and of vision, thinks that Television will become a monopoly of the telephone companies; that these will supply and install the necessary equipment for public and private uses, as they now do the telephone instrument; that they will supply entertainment via Television, the same way they now make telephone connections, that is, by request of the renter of the equipment, and will charge them accord- ingly. Dr. De Forest has even declared that these charges will be added to renter's monthly telephone bill. The theatre will make use of it this way.
Perhaps this is the way it will be done. Why not?
Another question concerns the nature of the equip- ment which theatres will use for Television. That question cannot be answered now. It may become part of the equipment now in use in the motion pic- ture theatre projection room; it may be necessary to place it on the stage and project on the screen from the rear — it may be one or both of these processes. But this is certain — theatres will need new equipment for Television and smart men to operate it.
Order a copy of TELEVISION today— price $3.50. SOUND PROJECTION ($6.00). The price is $8.00 for the two books. Order from the MOTION PICTURE
PROJECTIONIST, 45 W. 45th St., N. Y. C.
10
Motion Picture Projectionist
November, 1930
SIMPLEX REAR SHUTTER
A REVOLUTIONARY IMPROVEMENT
Illumination Increased 35 to 48% Heat Reduced 50 to 75%
Every Owner, Manager and Projectionist Should Send for Information Regarding
AND THE
NEW REAR SHUTTER ATTACHMENT
For SIMPLEX REGULAR PROJECTOR
SIMPLEX REAR SHUTTER PREVENTS BUCKLING
International Projector Corporation
90 GOLD STREET
NEW YORK
November, 1930
Motion Picture Projectionist
11
S. M. P. E. Fall Meeting Program
WITH an unusually varied pro- gram assured by the revised reports of the chairmen of the various committees, the forthcoming Fall Meeting of the Society of Mo- tion Picture Engineers at the Penn- sylvania Hotel, New York, October 20-23, inclusive, promises to set a standard for all future conventions of this organization. A glance at the list of papers scheduled to be read at the meeting assures the technically- minded motion picture worker of four days well-spent on this score alone. But there are other activities of the meeting which will appeal to all those who attend, first and most important of which is the interchange of opinion and experience in informal discussion the results of which are reflected in future progress in the arts.
More than 40 papers are down for presentation at the meeting, the 28th of the Society's existence. Classifica- tion of the subject mater of these con- tributions reveals that equipments for studio and theatre are discussed in 13 papers; 5 are concerned with labora- tory technique; 4 deal with theatre procedure; 4 on studio work; with several papers on color and a discus- sion of television helping to round out the list. In addition, several open forums are scheduled in which per- tinent topics will be discussed.
Interest in Wide Film
Overshadowing all other topics is the question of wide film standard- ization. Just what will happen at the meeting to help clarify the present badly muddled wide film situation is a topic of much pre-convention specu- lation. Published reports during the past few months have persisted in de- fining the Society's position on wide film standards as one of passivity, this despite the statement of Presi- dent J. I. Crabtree to the effect that the organization would continue to manifest a lively interest in the sub- ject and that no attempt would be made to limit discussion of the topic at the forthcoming meeting. There are many who profess to believe that the Society, having once expressed its position on the matter through the medium of a report by one of its com- mittees, would do nothing further along this line pending receipt of definite word from the producers con- cerning their attitude on standards.
That discussion of wide film stand- ards can be definitely restricted to merely a reading of a committee re- port is seriously doubted by those who are in a position best to know. Tre- mendous interest in the subject is ap- parent in all branches of the indus- try, and extended discussion of the matter appears inevitable.
The papers to be presented on sound recording and reproduction will reflect
Nat Golden, member of L. U. 160 and P. A. C. award winner, who is a com- mittee head for the S. M. P. E. meeting
no revolutionary development in this field but rather will stress the refine- ments which are constantly being made. One possible exception to this statement may be the paper to be pre- sented by H. von Madaler, who will describe his process of "sound grooves" on film, in which a repro- ducer unit "tracks" in the groove on the film in a fashion similar to a needle tracking in a disc. This proc-
Wide Film Standards
Regarding the attitude of the S. M. P. E. on wide film stand- ardization, it is understood that a Society committee after much consideration has submitted to the motion picture producers its suggestions and recommenda- tions with respect to the various processes. While the high rat- ing of the Society within the industry lends much authority to its findings in this respect, nothing further can be done until and unless the producers get together and decide whether there will be a cooperative effort at wide film standard- ization.
Conflicting reports as to the present attitude of the Society on wide film continue to find their way into the trade press, but a recent statement by President Crabtree to Motion Picture Projectionist indi- cated that there will be no at- tempt to limit discussion of wide film on the floor of the meetings. President Crabtree stated that wide film will re- ceive its "due share of attention at the Fall Meeting."
ess was commented upon in a recent issue of Motion Picture Projec- tionist.1
That existing methods of color photography are inadequate for the industry's exhibition requirements is gathered from the fact that several papers on improved color cinematog- raphy processes are listed for presen- tation. During the past year, and particularly within the past few months, there has been much severe criticism of existing color processes. Some difficulty has been experienced in the production procedure, and the finished product as shown in theatres has not been up to the general ex- hibition standard set by black and white subjects. A sharp improvement in color photography technique is very much desired by leaders in the production and exhibition branches.
Non-Theatrical Activity
Marked activity in the non-theatri- cal field has been noted in the past twelve months, and many important papers on this phase of the business will be presented at the meeting. No suitable method of recording sound on 16 mm. film has yet been achieved, despite the concerted efforts of rank- ing technical staffs throughout the country. Grain in film and linear speed relationship are thus far the unsurmountable problems of 16 mm. film recording. Several very inter- esting processes which involve the use of a 16 mm. picture in conjunction with a 35 mm. sound track have been announced, but there is a lack of per- tinent data available on these sys- tems.
There is a dearth of activity in the three-dimensional motion picture field, with not a single substantial contribu- tion having been made to the art within the past several years. "Sug- gestions of depth" and "illusions of depth" mark the borderline of present commercial stereoscopic ventures.
It is understood that a latest type model Grandeur projector unit will be set up at convention headquarters and that a complete film program will be shown by it. The new Grandeur mechanism is adaptable for both 35 mm. and 70 mm. film, the switch from one to another size requiring but a minute. It is not known definitely if this new Grandeur mechanism will be able to accommodate wide film sizes other than 70 mm. with similar little change.
The business meetings of the Society will be concerned with a sessions of the Board of Governors, election of officers for the coming year, and the laying of plans for a permanent head- quarters in New York City which will be in charge of the new general man- ager of the Society who is to be named
Sept., 1930, Vol. 3, No. 11.
12
Motion Picture Projectionist
November, 1930
at this meeting. This headquarters manager will also act as the editor of the S. M. P. E. monthly Journal.
Appended hereto are advance ab- stracts on some of the papers which will be presented at the Fait Meeting:
SOME CAUSES FOR VARIATIONS IN THE LIGHT AND STEADINESS OF HIGH INTENSITY CARBONS
D. B. Joy and A. C. Downes
Research Laboratories, National
Carbon Co.
The effect of the variation in the relative positions of the positive and negative carbons in a commercial high intensity lamp burning 13.6 millimeter carbons is investigated. The futility of specifying an arc voltage without fixing the position of the positive car- bon with respect to the negative car- bon is illustrated. It is also demon- strated that a relatively small move- ment in the position of the positive
carbon crater along its axis has a greater effect on the steadiness and quantity of useful light from the high intensity arc than is ordinarily sup- posed. The positions of the carbons at which maximum light and the max- imum steadiness of light are obtained are defined, and it is shown that for the same current the position of maxi- mum light is not necessarily the posi- tion of maximum steadiness.
PRINCIPLES AND PROCESSES OF PHOTOGRAPHY IN NATURAL COLORS Glenn E. Matthews Eastman Kodak Research Labora- tories
Almost from the first years in which motion pictures were used commer- cially, about 1895 to 1900, experi- menters have been working on methods of producing them in natural colors. The only practical processes
enjoying any extensive commercial use in the theatres, however, are sub- tractive processes in which the color is incorporated in the film. One ad- ditive process has had extensive ap- plication for amateur motion pictures for over two years. Within the past year a large number of color motion pictures have been released with sound accompaniment so that the ul- timate is being approached in motion picture photography, namely pictures in color and sound. No practical methods of obtaining stereoscopy or relief have as yet been found. The subtractive processes which have been used, however, are only two-color methods and therefore a true spectral record is not realized.
Although a simple process of color photography yielding a print which faithfully reproduces the colors of nature is greatly needed, most of the research at the present time is being directed to the perfection of color mo- tion pictures. Another equally im-
Program for S. M. P. E. Fall Meeting
Monday, Oct. 20th
8:30 to 10 A.M. — Convention Registration. 10:00 A.M. — Convention Called to Order
(Roof Garden, Pennsylvania Hotel).
Address of Welcome by Major Edward J. Bowes, Capitol Theatre, New York.
Response by the President.
Report of the Convention Committee.
Reports of the Secretary and Treasurer.
Election of Officers.
Report of Progress Committee — G. E. Matthews, Chairman.
"Meeting Sound Film Competition Abroad" toy C. J. North and N. D. Golden, M. P. Division, Bureau of Foreign and Domestic Commerce, Washington.
"International Relations in the Sound Picture Field" by F. S. Irby, Associate Editor, Electronics, New York.
"Some Observations of the M. P. Indus- try in Russia" by J. W. Coffman, Presi- dent, Audio-Cinema, New York. 1:00 to 2:00 P.M. — Luncheon. 2:00 P.M. — Papers:
"The Progress of Sound Motion Picture Presentation" by Harold B. Franklin, Los Angeles.
Report of -Standards and Nomenclature Committee — A. C. Hardy, Chairman.
Open discussion — "Methods of Securing a Large Screen Picture."
Report of Journal Committee — L. A. Jones, Chairman.
Report of Projection Committee — L. M. Townsend, Chairman.
"Principles and Processes of Photography in Natural Colors," by G. E. Matthews, Research Laboratory, Eastman Kodak, Rochester.
"Three Color Subtractive Cinematogra- phy," by Palmer Miller, Brewster Color Milm, Newark.
Demonstration Film of a Three Color Len- ticular Screen Process, by L. M. La Porte, Paramount Putolix, New York. Committee Reports:
Color Committee — W. V. D. Kelley, Chair- man.
Historical Committee — C. L. Gregory, Chairman.
Studio Lighting Committee — A. C. Downes, Chairman.
Theatre Lighting Committee — C. E. Ege- lcr, Chairman.
Membership Papers, and Publicity Com- mittees—II. T. Cowing, J. W. Coffman, W. Whitmore, Chairmen. 8:00 P.M. — Exhibition of recent films of in- terest in the Roof Garden, Pennsylvania
Hotel.
Tuesday, Oct. 21st
8:30 to 9:30 A.M. —
9:30 A.M. — (Roof Garden, Pennsylvania Ho-
"An Entertainment City," by R. N. Gold- smith, Vice-President, Radio Corp., New York.
"Recent Developments in Newsreel iSound Recording Equipment," by P. M. Robil- lard and E. F. Lyford, RCA Photo- phone, New York.
"Some New Studio Recording Equipment," by W. P. Dutton and S. Read, RCA Victor Co., Camden.
"Improvements in Dynamic Speakers," by I. Bobrovsky Serge, Consulting En- gineer, Rochester.
"Carbon and Condenser Microphones — Their Characteristics in Construction and Use," by W. C. Jones, Bell Tele- phone Labs., New York.
Open discussion : "Advantage and Disad- vantages of Placing iSound and Picture on Separate Films." 12:30 to 1:30 P.M. — Luncheon. 1:30 P.M. — Papers (Roof Garden, Pennsyl- vania Hotel) :
"Motion Study with the Motion Picture
Camera," by Alan Mogenson, Associate Editor, McGraw Hill Publishing Co., New York.
"A New Sound Picture Theatre Reproduc- ing System," by G. Puller, Bell Tele- phone Labs., New York.
"A New Type Glow Lamp for Recording Sound on Films," by Joseph B. Zetka, New York.
"The Madaler Process of Sound Recording and Reproducing," by H. Von Madaler, Hampton Bays, L. I.
Demonstration Film Recorded by the Use of a Reflector in Combination -with a Microphone — H. W. Dreyer and M. C. Batsel, RCA Photophone, Inc., New York.
"Film Noise of Non-Electric Origin," by John O. Frayne, Electrical Research Products, Hollywood.
"(Some Experiences in Adapting Theatres for Sound," by L. M. Townsend, Para- mount 'Publix, New York.
"A 16 mm. Portable Sound on Film Pro- jection Equipment," by C. R. Hanna, P. L. Irwin and E. W. Reynolds, West- inghouse, East Pittsburgh. 6:30 to 7:30 P.M. — Dinner.
Entire evening set aside for visiting Broadway theatres.
Wednesday, Oct. 22nd
9:30 A.M.— Papers (Roof Garden, Pennsyl- vania Hotel) :
"Cinematographic Analysis of Mechanical Energy Expenditure in the Sprinter," toy C. A. Morrison, Eastman Teaching Films, Rochester, and W. O. Fenn, Uni- versity of Rochester, School of Medicine and Dentistry. Rochester.
"Additional Characteristics of High In- tensity Arcs," by D. B. Joy and A. C. Downes, Research Laboratories, Na- tional Carbon, Cleveland.
"Double Toping of Motion Picture Film," by L. I. Crabtree and W. Marsh, Re- search Laboratory, Eastman Kodak, Rochester.
"Some Observations on Stereoscopic Pro- jection," toy J. B. Taylor, Research La- boratory, General Electric, Schenectady.
"Removing the Fire Hazard from the Handling and Storage of Film in La- boratories," by R. C. Hubbard, Consoli- dated Film Industries, New York.
"iSome Applications of the Comparison Microscope in the Fiilm Industry," by O. E. Conklin, Redpath Laboratory, Du- Pont Pathe Film, Parlin, N. J.
"The Rocono Treatment for Film Reju- venation," by A. P. Rittenbein, New York.
"Reducing Solutions for Motion Picture Film," by J. I. Crabtree and L E. Muehler, Research Laboratory, Eastman Kodak, Rochester. 1:00 to 2:00 P.M. — Luncheon. 2:30 P.M.- Boat Trip Around Manhattan Island. Boat leaves Battery Pier at 2 :30 P.M. 7:30 P.M. — Semi-Annual Banquet in the Grill Room of the Pennsylvania Hotel. Dancing afterward.
Thursday, Oct. 23rd
9:30 A.M.— Papers (Bell Telephone Labora- tories) :
"A Modern Laboratory for the Study of Sound Picture Problems," by E. E. Shea, Bell Telephone Labs., New York.
"Peculiar Engineering Problems in the 16 mm. Field," by E. C. Fritts, Eastman Kodak, Rochester.
Two-Way Television Demonstration by H. E. Ives, Bell Telephone Labs, New York.
"A Damped Diaphragm Sound Repro- ducer," by Rudolph Miehling, Universal Sound System, Philadelphia.
"The World's Most Powerful Microscope," by F. F. Lucas, Bell Telephone Labs., New York. 1 :30 to 2:30 P.M.— Luncheon (courtesy of
Bell Telephone Labs., Inc.). 2:30 P.M. — Trip through Bell Telephone La- boratories, including Sound Film Labo- ratory. 7:30 P.M.— Papers (Roof Garden, Pennsyl- vania Hotel) :
"Two-Solution Development of Motion Pic- ture Film," by J. I. Crabtree, H. Parker and H. R. Russell, Research Labora- tory, Eastman Kodak, Rochester.
"Aiding the Theatre Patron Who Is Hard of Hearing," by F. H. Graham, Elec- trical Research, New York.
"The Photoflash Lamp," by Ralph E. Parnham, General Electric, Cleveland.
"Higher Illumination for Non-Professional Projector Equipments with Low Voltage Tungsten Filament Lamps," toy V. J. Roper, General Electric, Cleveland.
"Electrical Instruments for Test Pur- poses," by A. H. Wolferz, Weston Elec- trical Instrument Corp., Newark.
"A New and Simplified 16 mm. Projector and Camera," by C. E. Phillimore, Peko, Inc., Chicago.
November, 1930
Motion Picture Projectionist
portant field is the use of color pho- tography in photomechanical printing processes as colored illustrations have come into very extensive use during the past fifteen years. The work of different investigators may naturally be divided into (1) still photography including color photographs to be viewed by transmitted light and by reflected light, and (2) motion picture color photography.
(The discussion of the different pro- cesses as given in the lecture is pref- aced by a description of the prin- ciples involved in the photographic re- production of color.)
ELECTRICAL INSTRUMENTS
FOR TEST PURPOSES
A. H. Wolferz
Weston Electrical Instrument Corp.
This paper contains the outline of a proposed electrical test set for servic- ing sound projection equipment and other similar apparatus. The pro- posed set is portable and will be use- ful in carrying out the following tests :
Testing of the amplifier tubes.
Measurements of filament or heater voltages or currents, plate voltage and current, grid voltage, cathode voltage at the tube socket while the amplifier is in operation.
Measurements of rectifier tube plate currents and transformer secondary voltages.
Resistance measurements and con- tinuity of circuit tests.
Capacitance of condensers.
Input and output voltages of am- plifiers.
THE MADALER PROCESS OF
SOUND RECORDING AND
REPRODUCING
H. von Madaler
After 10 years of experimenting the writer has succeeded in producing an entirely new talking film of a quality equal to the systems now in use, and also having several advantages over these systems.
First, the recording can be immedi- ately reproduced as soon as it is re- corded and can be played over 250 times without losing any of its quality; second, it is not necessary to reduce the size of the picture frame as is the case of the present sound photo- film systems; third, any colored film can be recorded successfully and oil, dirt and scratches on the film do not affect sound reproduction.
The record groove on this new talk- ing film is exactly like the Victor record. The depth and width is about two thousandths of an inch and this record is impressed with a diamond point which is half round on the point. The film is also reproduced with a similar point.
Recording has been sucessfully achieved on a standard film 35 mm. with a speed of 90 feet per minute and
S.M.P.E. Membership Gain
The total membership of the S. M. P. E. now approximates 750, according to a recent report of the Membership Committee. Interest in the Society nas grown enormously within the - past several years with prac- tically every branch of the in- dustry now having many repre- sentatives on the Society roster. The formation of local Society sections is believed to have given impetus to an aroused interest in the Society, the various local memberships hav- ing established regular meeting dates for sessions at which inter-convention happenings are discussed.
Society officials are looking forward to a membership of 1,000 or more by the time of the Spring Meeting in 1931.
also on a 16 mm. film at a speed of 24 pictures per second or 36 feet per minute. A thorough test in recording was made in the experimental labora- tories of the Eastman Kodak Com- pany at Rochester and it was found, with the help of an oscillator, that there was no difficulty in recording frequencies from 50 to 5,000 cycles on a 16 mm. film which has a two and a half times slower speed than the standard 35 mm. film. This film has now sufficient quality to be put on the market.
For recording the sound waves there has been constructed a very simple machine which consists of a sprocket of about 1SA inch diameter which is mounted on a shaft on one end and a suitable flywheel on the other end. This flywheel is driven from a synchronized motor in the usual way. For reproducing a similar device is used and an electrical pickup is employed for reproducing the sound.
There has been constructed a spe- cially made electrical recording unit which is more powerful than any other recording unit as much more power is needed to engrave in a celluloid film than in a wax record. The film is recorded in its ordinary cold state and no preparation is necessary for recording on the film. For recording on the standard film a 4 stage double push-pull 250 tube amplifier is used and for reproducing this same ampli- fier can be used also.
For reproducing and recording a 16 mm. film a 4 stage 245 push-pull amplifier is used with very good re- sults.
It is hoped that this new system will be used universally in all the- atres and homes on account of its sim- plicity, manufacture and operation; and also because the cost to produce this film will be much less than that of the present systems now in use.
A DAMPED DIAPHRAGM RE- PRODUCER Rudolph Miehling Universal Sound Systems
This paper deals with a new type of speaker recently perfected which dif- fers from both exponential and cone type horns and yet retains the best features of both. It is termed the Damped Diaphragm Reproducer be- cause of the peculiar construction of this portion of the instrument. It employs a large, metallic diaphragm rigidly attached to a heavy iron ring. The dynamic driving system is at- tached to the center of the diaphragm and serves to actuate the diaphragm. The diaphragm, which is made of duralumin, .002 of an inch thick, is not stretched on the ring so its natural period of vibration will be above aud- ibility. The tension on the diaphragm is such as to place its resonance point within the audible range.
To prevent resonance at this par- ticular frequency the diaphragm is damped by attaching strips of balsa wood so placed that its response is constant throughout the audible range. By the proper arrangement of damp- ing strips, adjustment of air gap and diaphragm tension, it is possible to tune the speaker so that it will have a rising characteristic as the fre- quency increases or a falling charac- teristic as may be most desirable under the conditions met with in its use.
Its wide range of frequency re- sponse and its characteristics over that range enables this speaker to meet easily all demands of the sound projection field. Its high efficiency and permissible power input as well as its wide distribution characteristic make it desirable from the standpoint of economy, both in lowered amplifier output and reduced number of units necessary for given sound level. To these must be added the factor of nat- uralness or fidelity of output. This can only be determined by hearing tests but when a speaker produces sound that is easy to listen to and un- obtrusive, these requirements have also been met. On all points then, the damped diaphragm reproducer prom- ises better sound at less cost.
CINEMATOGRAPHY WITH THE LARYNGOSCOPE
C. A. Morrison Eastman Teaching Films
A new technique for making motion pictures of the vocal cords has been developed by the use of a quartz rod as the means of projecting a high in- tensity illumination within the larynx. The source of light consists of the two filaments of an over-volted auto- mobile bulb. A laryngoscope, illumi- nating system and viewing finder are attached to a 16 mm. motion picture camera. This combination forms a self-contained, one-man-controlled di- agnostic unit, which permits motion
14
Motion Picture Projectionist
November, 1930
pictures of the cords to be made at the standard rate of 16 frames per second. The field photographed is viewed constantly through the finder by the operator, who controls the spring motor of the camera by the usual release button. The pictures as projected fill the entire screen area. This is a magnification previously un- attained under these conditions.
special problem as far as size and dimensions of coupling medium are concerned. Necessity of a super dy- namic speaker which will reduce numerous technical problems is evident.
IMPROVEMENTS IN DYNAMIC
SPEAKERS
I. Bobrovsky Serge
Utah Radio Products Corp.
Acoustical problems are considered on the basis of a point source of sound. The number of sound sources leads to a number of technical prob- lems. One unit is ultimate solution, not yet reached. But necessity of fewer units is imperative.
Problem was to develop a cone type dynamic speaker which will have large power of ratio, so that the ideal con- ditions may be approached. Problems of developing cone dynamic speaker for auditorium use are numerous and I bring a most important one.
1. Increase of output results in increased size of voice coil.
2. Maintaining as high flux density in the air gap to obtain highest ratio between mechanical watts radiated to electrical watts input. This accom- plished by developing an alloy with highest possible saturation point than material used at present tima com- mercially.
Reduction of Leakage
3. Proper design of magnetic cir- cuit which will develop maximum flux in the air gap for the total given flux. That results in selection of a set of dimensions to obtain minimum leak- age flux. Substantial reductions of leakage are secured in design of new super dynamic speaker.
4. Increase of pole face to give a large and uniform density in the air gap. That will result in maintaining voice coil in uniform flux densities at all amplitudes to prevent subsequent variations in impedance that are det- rimental to conversion efficiencies.
5. Use of proper number of turns and resistance for the field winding of the speaker unit. Inasmuch as fewer units are to be used, with the super type of dynamic speaker, higher field watts input are permissible.
6. Cone of dynamic speaker and its suspensions is a very important fac- tor. Continuous experiments with cone and its suspensions produced a cone which is able to withstand high ratio of transfer of electrical energy to mechanical energy.
Proper Coupling
7. Proper coupling of sound pro- ducing unit with an auditorium is very important problem and use of baffle horn seems to be superior to the other type of coupling.
However, each auditorium presents
REQUIREMENTS FOR A PRAC- TICAL SYSTEM OF THREE COLOR SUBSTRACTIVE CINEMATOGRAPHY Palmer Miller and P. D. Brewster Brewster Color Film Co.
Our paper first considers the neces- sary requirements in the camera — the comparison of advantages of using a single negative to record the three color separations and the use of three separate negatives — followed by a study of the advantages of using sep- arate films sensitized for different colors, to aid in obtaining sharp sep- arations in comparison to the use of panchromatic film and filters.
The Camera Lens
The question of the speed and the range of focal lengths of the lenses re- quired in the cameras for practical use in the studios are considered.
Different possibilities for the pro- duction of the positive prints are then considered with special attention to dye mordaunting processes. Require- ments as to definition of the image, range of color and clarity of color are discussed.
Paper concludes with a number of slides, showing curves of filters, curves of desired color separations and transmissions of H & D strips. The effect of superposing different color strips is demonstrated.
DUBBING AND ITS RELATION TO SOUND PICTURE PRO- DUCTION
George Lewin Paramount-Publix Corp.
I Meaning of Dubbing
(a) Originally applied to straight re-recording.
(b) Now usually applied also to synchronizing and scoring in which sound tracks are used.
(c) Also used to describe faking of dialogue for foreign versions of domestic pictures.
II Reasons for Dubbing
(a) To transfer from film to disc or vice versa for release pur- poses.
(b) To re-record for purpose of equalizing level variations, or changes in quality.
(c) To add sound effects which can best be recorded artifically.
(d) To add sound effects or music which would hamper the orig- inal recording or stage action, if made while original recording was taking place, or which would be spoiled when film is edited.
(e) For scoring and synchronizing, using sound tracks instead of direct pick-up on music, to avoid use of an expensive orchestra for a long period.
(f ) For adding sound effects from sound tracks, where it would be
difficult or impossible to use direct pick-up of the sounds — such as real street noises, train noises, applause, etc.
III Kinds of Dubbing
(a) Straight dubbing
1. Film to disc
2. Disc to film
3. Film to film
4. Disc to disc
(b) Combined dubbing and syn- chronizing.
1. From film, non-synch, outfits and direct pick-up to film or disc.
IV Technical Problems in Dubbing
(a) Reproduction of sound for dubbing must be better than for reproduction in theatres.
1. Defects of ordinary projectors.
2. The problem of "green" film.
(b) Special machines for high quality reproduction.
1. Modified film recorder for re- production.
(c) Frequency characteristics of recording and reproducing ap- paratus.
(d) Dubbing equalizers.
V Other Forms of Indirect Recording
(a) Subsequent photography.
(b) Dialogue faking in extreme long shots, or where speakers are not visible.
(c) Trick effects.
A 16 MM. PORTABLE SOUND ON FILM PROJECTION EQUIPMENT
C. R. Hanna, P. L. Irwin and E. W.
Reynolds
Westinghouse Elec. & Mfg. Co.
A portable sound on film projection equipment using 16 mm. film is de- scribed. The film is standard with the exception that one row of sprocket holes is omitted to provide space for the sound track.
The projector is only slightly larger than the average silent picture pro- jector. Detailed description of its mechanical, electrical, and optical features is given.
Complete in '3 Cases
The complete equipment is mounted in three carrying cases, one for the projector, one for the amplifier, and one for the loud speaker and screen. The projector case serves also as a soundproof housing when the equip- ment is in operation. The rewind, splicer, cables, spare tubes and lamps, and the films are located in the case for the loud speaker and screen. Each of the carrying cases weighs ap- proximately 40 pounds, making the total weight of the equipment 120 pounds.
November, 1930
Motion Picture Projectionist
A Standard Release Print
A FORM of standard release print which is expected to clarify for all time the problem of uniform projection with respect to standardized changeovers and thereby save the industry at least a million dollars yearly in replacement print costs has been promulgated by the Academy of Motion Picture Arts and Sciences, of Hollywood, in collabora- tion with every technical branch of the motion picture industry. The standard becomes effective November 1.
The standard was worked out by a sub-committee of experts under super- vision of The Academy Producers- Technicians' Committee, of which Irving G. Thalberg is chairman, and involved survey, analysis, and corre- lation of practices and opinion of technicians in the studios, laboratories and theatres throughout the country, production of test reels, and experi- mentation with various methods.
The committee of experts which worked out specifications for the standard consists of Sidney Burton, representing the projectionists; N. H. Brower, representing the exchanges; A. J. Guerin, laboratory representa- tive; I. James Wilkinson, film editor; and Gerald F. Rackett, former man- ager of the Technical Bureau. Sidney J. Twining, another representative of the laboratories, served as chairman.
Salient Features of Plan
Salient features of the new stand- ard are as follows:
1. Standard nomenclature for different types of prints as well as for the units comprising each reel.
2. Standard inscription for identi- fication.
3. Standard synchronizing marks.
4. Standard method for change- over from reel to reel.
During the next three weeks an advance educational program will be conducted to pave the way for the standard. It is hoped to reach every theatre, exchange, and studio in the country acquainting theatre and ex- change managers, projectionists, film editors and laboratory executives with the features of the new standard.
In bringing about a uniform method of change-over, one of the most irk- some problems in projection should be solved. At the present time the individual projectionist puts on his own change-over marks. These ac- cumulate and give rise to a constant demand for replacement by exchanges.
The new change-over signals consist of circular opaque marks with trans- parent outline printed from the nega- tive. Each signal is four frames in length and is placed in the upper right hand corner of the frame. At the first signal, known as the motor
cue, the projectionist starts the motor of the incoming machine; at the second signal, known as the change- over cue, the change-over is accom- plished.
12-Foot Pick-Up
The time between the two signals is eight seconds or twelve feet of film. This allows the incoming machine to pick up to normal speed and reach the continuation of the picture in time to accomplish the change-over smoothly.
After the projectionist has de- termined the time of pick-up of his machine he will know how many feet of film his incoming machine requires while the final twelve feet is being run out on the outgoing machine. He
identifies this footage with a number on the synchronizing leader and threads up accordingly.
In addition to the change-over sys- tem, the standard specifications cover the leaders both at the beginning and end of the picture. At the beginning the leader consists of three parts: protective leader (4 to 6 feet), identi- fication leader (4 feet), containing the part number and picture title.
This is followed by a synchronizing leader (14 feet in length) the first section of which (2 feet) is opaque followed by a frame in which the word "start" is printed in black letters on a white background. Foot- age indicator numbers on the syn-
To the Projectionist:
PRESENTATION in these columns of data on the new standard release print would be incomplete without some supplementary statement such as this. Certain facts are self-evident from merely a casual reading of the specifications of this new standard; but there is another phase of the situa- tion which should be clarified — and that the position of the projectionist with respect to the introduction of the standard.
Someone has said that any standard represents merely a difference of opinion, and this certainly is true of the release print standard. The latter is not an arbitrary code drawn up to the liking of any special group within the industry but is the result of months of painstaking work on the part of all motion picture technical branches. There is nothing compulsory about this standard — it represents a cooperative movement on the part of pro- ducers, studio workers, exchanges, and projectionists, and simply because it is a cooperative effort the responsibility of each and every branch of the industry to put the idea over is increased tremendously.
The standard is flexible in that if practice proves it inadequate in any respect it can and will be changed to meet conditions. The standard repre- sents the consensus of opinion at the moment — all are agreed that a change will be made if necessary. There may be some — or many — projectionists who disapprove of the standard. The writer through long experience has been made aware of many "ideal" plans for the perfect changeover, but he has never come across one that could be seriously considered as a standard. Criticism of the new standard is expected — is, in fact, welcome. After November 1, when the new standard goes into effect, we hope to find our mail bag crammed with comment on the plan. Favorable, lukewarm, unfavor- able— whatever the temper of your reaction may be, send it in. We would like to get the reaction of every projectionist in the country to this plan. Don't hesitate; send in your thoughts on the matter and they will receive full consideration. Without this help the work expended on the standard will go for naught.
Without the cooperation of the projectionist this standard release print plan is not worth the paper on which it is written. Some projectionists will say, "I don't like the plan"; but he will not be fair to himself and to his brother craftsmen if he doesn't take the trouble to tell us WHY he doesn't like it. As a matter of fact, every projectionist in the country had a hand in the drafting of the plan, just as surely as though he had sat in on conferences on the matter. Your representatives — men who rank highest in your craft — have given their time and a lot of hard work to secure consideration for your ideas. They have spoken for you — thus far. .The rest is up to you.
Plans are now in the making to place a copy of these release print specifica- tions in the hands of every projectionist in the country. The full resources of the Academy of Motion Picture Arts and Sciences, American Projection Society, and Projection Advisory Council are behind this standard and nothing will be left undone to put it across. As we said before, the degree of success attained in this movement is up to each individual projectionist. The battle will be fought in the projection room and not with type, ink and paper.
It's up to you now, and you will be judged solely on the basis of performance.
JAMES J. FINN.
Motion Picture Projectionist
November, 1930
chronizing begin three feet from the first frame of the picture and are numbered three to eleven.
The ending of the reel will consist of 6 feet of opaque runout trailer, 4 feet of identification trailer, and 4 to 6 feet of protective leader.
Projection Leaders Aid
Leaders among the projectionists who have been active in the progress of the standard are George Edwards, International President, American Projection Society; Thad Barrows, President, Projection Advisory Coun- cil; Harry Rubin, Supervisor of Pro- jection, Publix Theatres; Jess Hop- kins, Publix Theatres; R. H. Mc- Cullough, Supervisor of Projection and Electrical Equipment, Fox West Coast Theatres; Lester Isaac, Super- visor of Projection, Loew Theatres; Le Roy Cox, Supervisor of Projection, R-K-0 Theatres; Charles Eichhorn, Vice-President of Local Union 306, New York City; P. A. McGuire, Executive Vice-President, Projection Advisory Council; and James J. Finn, Editor, Motion Picture Projection- ist.
Sidney Burton, First Vice-Presi- dent of the Council and President of Chapter 7, A. P. S., was, of course, a member of the committee which drafted the standard.
Efforts to improve the make-up of release prints and change-over cues were begun in Hollywood more than a year ago. The confusion and com- plete lack of uniformity among studios was one of the by-products of the abrupt introduction of sound. Until the more urgent production problems could be taken care of many important factors contributing to the presentation of the picture had to wait.
In September of last year the need for correlating practice in the make- up and handling of release prints was
Print Nomenclature
Four types of film are denned in the standard nomenclature per- taining to the new release prints, as follows:
Sound Print-Film — A print with a photographic sound record in- tegral with the print. Sound Print-Disc — A print with a
disc sound record. Sound Print-Film and Disc — A print with a photographic sound record integral with the print and a corresponding disc sound record, either of which may be used. Silent Print — A print without a
sound record. Leader — That part of the print from the beginning to the first frame of picture. Picture — That part of the print between the leader and the run- out. Runout — That part of the print from the last frame of the pic- ture to the end.
recognized and a committee was formed by joint action of the Tech- nicians Branch of the Academy of Motion Picture Arts and Sciences, the local chapters of the American Pro- jection Society, the American Society of Cinematographers and the Society of Motion Picture Engineers. This committee included: Sidney J. Twin- ing, chairman, manager of sound track laboratory, Paramount-Publix West Coast Studios; N. H. Brower, then president of the Los Angeles Film Board of Trade; A. J. Guerin, manager of Plant No. 7, Consolidated Film Industries, Inc.; Sidney Burton, president of the California Chapter, American Projection Society; Gerald F. Rackett, then manager of the Technical Bureau; I. James Wilkin- son, chief film editor of Paramount- Publix West Coast Studios; and
Donald Gledhill of the Academy Technical Bureau, secretary.
The committee attacked the problem and set about drawing up tentative specifications for release print prac- tice which could be made uniform. The cooperation of the Academy and of the Association of Motion Picture Producers was extended to the pro- ject. The original group was consti- tuted a sub-committee of the Pro- ducers-Technicians Committee of the Academy and representatives of the seventeen major studios were ap- pointed to collaborate with them.
During the subsequent months, various aspects of the problem were carefully studied by the committee, test reels were made, and a series of meetings with the studio, theatre and exchange representatives and confer- ences with smaller groups were held
Specifications of Standard Print
Parti
PROTECTIVE LEADER
Either transparent or raw stock.
When the protective leader has been reduced to a length of four feet it is to be restored to a length of six feet.
IDENTIFICATION LEADER (Part Title)
Shall contain not less than 52 frames in each of which is plainly printed in black letters on white background, type of print (See Nomenclature), part number (Arabic numeral not less than J of frame height), and picture title.
4 Ft.
SYNCHRONIZING LEADER
First section shall be opaque.
Start mark shall be one frame in which is printed START (inverted) in black letters on white back- ground 1/2 of frame height.
A white line 1/32 inch wide upon which la super- imposed a diamond 1/8 inch high by 3/8 inch wide ehall be printed across the picture and sound track area at a point exactly 20 frames ahead of the center of the etart frame.
Beginning 3 ft. from the first frame of picture, each foot is to be plainly marked by a transpar- ent frame containing an inverted black numeral at least 1/2 frame height. Footage indicator numerals shall run consecutively from 3 to M, inclusive.
This section shall be opaque and contain frame lines thruout entire length which do not cross sound track area.
At a point exactly 20 frames ahead of the center of each footage numeral frame there shall be a diamond (white on black background) 1/8 inch high by J/8 Inch wide.
O |SOUNO PRINT FILM-DISC
Leader
2. Ft.
12Ft.
PICTURE
It is recommended that picture
action start and finish on fades nherever possible, otherwise sig- nificant sound should be kept at least five feet from the start and finish of the picture.
TT
November, 1930
Motion Picture Projectionist
17
to insure that the specifications repre- sent an efficient and practical solution.
Subject to Revision
Of interest is the following joint statement issued by S. J. Twining, chairman of the Sub-Committee on Correlation of Release Print Makeup Practice, and Lester Cowan, Manager of the Academy Technical Bureau:
"These specifications have been worked out during the past eight months by a sub-committee of the Academy of Motion Picture Arts and Sciences in advisement with techni- cians apointed by the seventeen major Hollywood studios and theatre and exchange representatives. The stand- ard release print applies to sound prints on film, on disc and combina-
tion prints. It is designed for adaptability to studio production and dubbing requirements, to laboratory practice, to efficient handling in ex- changes and to better enable pro- jectionists to make change-overs with- out rehearsal or marking and mutilat- ing prints.
"The following pages are a pre- liminary outline of practice in rela- tion to the makeup, maintenance and theatre handling of prints.
"Revision of the specifications will be made periodically as necessary to further the general purpose of con- tributing to the highest quality of sound picture presentation."
The standard release print was de- signed to make threading up, syn- chronizing, change-over and handling
Specifications of Standard Print
Part II
:otop. CPE
Shall be circular opaque marks with transparent outline printed from the negative *:.icL '.»ua had four consecutive frames punched with a serrated edge die .334 inch in dia- meter. The center of these holes is to be half-way between the top and second sprocket holes .281 inch from the right-hand edge of the film with heads up and enulsion toward the observer.
11 Ft.
:hange-over cpe
Shall 'ire the same as "otor Clue.
1 Ft.
RUNOUT TRAILER
Shall be opaque.
Picturfl
6 Ft.
IDENTIFICATION TRAILER (End-of-part title)
Shall contain not less than 32 frames in each of which is plainly printed in black letters on white background! End of Part, part number (Arabic numeral not less than f of frame 4 Ft. height), and picture title.
PROTECTIVE TRAILER
Same as protective leader.
4 Ft.
to 6 Ft.
a END OF PART
TITLE
Runout
Running 4 Direction |
Emulsion up.
of prints easier for the projectionist. Take advantage of the new system as you would an improvement on your machine.
Spend a half hour in rehearsing change-over on the first standard print that comes in to your theatre in order to determine the pickup of your machines. As the leaders and cues on all standard prints will be just the same from then on, all change-overs will be just the same.
1. Every standard print you re- ceive from the exchange will have the words printed or stamped on the reel band.
2. Do not mark or mutilate any footage of leader ahead of the action or in the runout. Remember that the reason the standard is a convenience to you is because it is measured ex- actly.
3. The protective leader and the protective trailer are never to be less than four feet or more than six feet in length when sent out by the ex- change.
4. Any special instructions by the producer of the picture will be found in the two feet of leader immediately following the part title and the two feet immediately following the end-of- part title.
5. How to Find "Actual Change-over Footage"
Fifteen or twenty minutes re- hearsal per machine will be necessary when you receive your first picture made up on the standard release print. Once you know your speed you can change-over between any standard prints from then on without any ad- ditional cues or rehearsal.
The "actual change-over footage" is the length of leader which must be left to run through the incoming ma- chine in order to make a perfect change-over. In other words, it rep- resents the leader that will run through the incoming machine in eight seconds. (Eight seconds is re- quired to complete the change-over as the start motor cue is twelve feet from the end of the outgoing reel).
The easiest way to determine your "actual change-over footage" is to re- hearse by placing the footage frame numbered 11 in the aperture of the incoming machine. Then change-over according to the cues, starting the motor of your incoming machine the instant you first see the start motor cue and throwing the douser switch the instant you see the change-over cue. If there is a lapse between the two reels showing on the screen try it again by placing the footage frame number 10 in the aperture of the in- coming machine. Continue this proc- ess with the same machine trying footage frame numbers 9, 8, 7 and so on until you have found the foot and the frame in the foot which when threaded up at the aperture will give you the exact change-over. This frame then marks your exact change- over footage for that machine. As all standard prints will be of exactly the
18
Motion Picture Projectionist
November, 1930
same leader footage you will be able to run down to the footage frame number you have found to be neces- sary for a perfect change-over and this same frame number will always be in your picture aperture when starting the incoming machine. Re- peat the timing process for the other machine or machines as there is often appreciable variation between the pickup speed of two machines in the same projection room.
6. Threading for Disc
In threading up for disc, set the needle on the disc at the synchroniz- ing mark and thread the start mark frame into the picture aperture of the projection machine. Then turn down the machine until the proper footage numeral appears in the picture aper- ture. If the turn down is not made in this manner, changing over from the signals on the outgoing reel will not be successful.
When running down the machine to the proper footage number note the revolutions of the turntable. This will simplify the process of threading.
7. Threading for Movietone
Once you have determined the actual change-over footage which must be left to run through the in- coming machine it is simple to thread up each standard leader so that the same footage frame number will be at the aperture ready for the start.
If you wish to test the length of your loops to insure synchronism thread up so that the start frame or any numbered footage frame is the aperture. A diamond mark will show at the sound gate as the diamonds are placed twenty frames ahead of the start frame and footage numerals. You can then turn down to have the exact frame in the aperture for the change-over footage.
8. Change-over
When you see the motor cue start the incoming machine.
Harry Rubin, P. A. C. Technical Co- ordination Committee
Sidney Burton, member of Standardiza- tion Committee
When you see the change-over cue throw the douser switch.
9. The Cues
The motor cue is a circular opaque mark with transparent outline printed in the upper right hand corner of four consecutive frames. The first of these frames is exactly twelve feet from the end of the picture. This distance, like the length of the syn- chronizing leader, was designed to accommodate the variety of pickup speeds among machines in use.
The change-over cue is a mark like the motor-cue on four consecutive frames, the first of which is one foot from the end of the picture. In plac- ing the change-over cue in this posi- tion it was assumed that the average time lapse occurring when an alert operator sees the cue on the screen until he throws the douser switch is half a second. It is essential that the operator throw the switch immediate- ly the cue flashes on the screen if the change-over is to be perfect.
10. Counting Disc Revolutions
When playing discs with standard release prints many projectionists prefer to count the revolutions of the disc to reach the proper turn down for perfect change-over.
11. Change-Over on RCA Machines
Because of the almost instantaneous pickup of RCA projectors, reels may be threaded up at the start frame for these machines and the standard signals at the end of the outgoing reel employed for motor start and change- over. In this case practically the same amount of footage will be run through on the incoming reel as on the outgoing reel.
12. Partial Exceptions to Standard Prints
It will naturally be some time be- fore the standard release print comes into universal use throughout the
country, as past releases will continue in circulation.
The dubbing process of some pro- ducers realizing on disc necessitates the use of more than twelve feet of leader between the start frame and the action. These prints will be standard in other respects and as the footage will be numbered at every foot up to the start frame the pro- jectionist can readily see the length of his leader without measuring.
Handling Standard Prints In the Exchange
1. Exchange Film Inspectors are expected to make sure that every print inspected conforms to the measurement outlined in the Standard Specifictions. Any cut outs or mu- tilations in either the leader or run- out will affect the change-over. It is suggested in this regard that a stand- ard charge be made for any mutila- tion of leader or run-out and that any theatre returning a print with a reel damaged in this manner be charged for it, and that a complete new leader or run-out be used each time rather than making patches.
2. The protective leader and the protective trailer attached to the front and end of the leader and run- out respectively are intended to fa- cilitate threading and protect the rest of the print. When either leader has been whipped down to four feet, the length should be restored to six feet by the exchange inspector before sending that reel out again.
3. It is suggested that the nomen- clature of the parts of a print be thoroughly understood and used by all exchange employees handling prints.
4. It is important that the exchange stamp or print the words STAND- ARD PRINT MAKEUP on the band of every reel which fulfills the stand- ard specifications.
Makeup of Reels In the Studio
The standard print will be a dis- tinct convenience to the studio cutter and in the handling of negatives through the dubbing processes.
1. While each reel division involves
Herbert Griffin, P. A. C. Technical Co- ordination Committee
November, 1930
Motion Picture Projectionist
19
an individual problem in cutting it is recommended that picture action start and finish on fades wherever possible. Otherwise significant sound should be kept at least five feet from the start and finish of the picture. This extra footage insures steadying down of the projector carrying the in- coming reel before significant sound is reproduced and also allows a mar- gin of safety on the change-over.
2. In the case of change-over on a fade, the fade itself is considered as "picture" in the terms of the specifi- cations. The change-over cue will be put 12 feet and the motor cue one foot from the end of the fade. The six feet of opaque run-out trailer is in addition to the fade.
3. The line across both picture area and sound track twenty frames ahead of the start mark frame will serve as the base for all matching of sound track and picture in making up the original negative.
4. The protective leader and the protective trailer of course apply
specifically to the release print. How- ever, these lengths of either trans- parent or raw stock can with advan- tage be carried through most of the studio operations.
5. The form of the part title is definitely specified. The part title is to occupy at least the first 32 frames of the Identification Leader. It may be extended to the entire four feet if desired. Otherwise the second 32 frames may be left blank or provide space for cueing or other instructions according to individual studio policy.
6. As the Synchronizing Leader is uniform for all prints it is only neces- sary for the cutting department to specify it to the laboratory. If these leaders are applied by the cutting de- partment to sample prints, care should be exercised to see that the synchronizing leader has been re- tained in its full length.
7. The visible signal will show as a black dot against light background and as a white circle against dark background. No special cutting is necessary on account of the signal.
Asks Tolerance and Understanding
(In Answer to Sidney Burton)
IN the October issue was published a statement by Sidney Burton, Vice-President of the Projection Ad- visory Council and President of A. P. S. Chapter 7 which set forth in ad- mirable style the position of the pro- jectionist in the general scheme of things in the motion picture industry. The general tenor of Mr. Burton's re- marks was that the projectionist was being unfairly treated by the industry at large in that the fine quality of work he was doing was being ignored and instead of receiving praise for good work he was too often blamed unjustly for certain apparent defects in reproduction which were wholly be- yond his control. A letter in reply to Mr. Burton was recently published in Loudspeaker, A. P. S. Chapter 7 organ and the source of Mr. Burton's statement, by Mr. Lester Cowan of the Academy of Motion Picture Arts and Sciences. This letter follows:
"I have read with interest your re- cent statement which discusses In a very sincere and direct manner the problem of placing responsibility for inefficiency or inadequacy with regard to quality of sound pictures as shown in the theatres.
An Important Point
"As spokesman for your fellow craftsmen you naturally resent any question or implied charge of ineffi- ciency, and you feel it unfair that the projectionist, being last in line, should often have to personally assume the burden of responsibility for all the errors that have accumulated along the way in the course of production and handling of the film. I think you raise a very important point and one
in which the Academy, as I explained to your membership the other night, is vitally interested.
"Let us analyze the nature of our product from a technical standpoint. First of all, the quality of a sound picture must be in the original nega- tive. If the director, cinematographer and associates do not succeed in get- ting quality into the negative, cer- tainly none of the succeeding crafts- men can make much improvement. Assuming that this quality has been attained originally, then the respon- sibility of those who handle the film or record from there on is to maintain and preserve this quality as faithfully as they can, finally delivering it from the screen to the audience in the theatre. In this process the studio technician is concerned primarily with getting on to the negative, the labora- tory in making prints which transmit this quality, the exchange in maintain- ing the film from a physical stand- point, and finally the projectionist in reproducing it in a manner that will deliver the best quality within the possibilities of his equipment.
"First, we must recognize the fact that the projectionist cannot go be- yond the limitations of his equipment. Second, if he gets an inherently bad print which never should have been sent out or a print which has not been properly cared for he certainly cannot be expected to give the type of quality that one might hear from the first answer print run in the studio under ideal conditions.
Good Show the Problem
"So, all in all, we have the problem of giving the audience a good show
both from the standpoint of picture and sound. This is dependent upon the efficiency of a series of craftsmen any one of whom has the power of spoiling the final show; and the pro- jectionist is in a position where he will show the product as given him and if this product contains mistakes and is faulty in other respects he can- not do anything but project the bad features along with the good.
"The Academy stresses that every individual craft — projectionist, sound engineer, laboratory technician, and all the others — should realize that the quality of sound pictures will not be improved if we devote ourselves to buck-passing and blaming the other fellow. Progress will come only with the realization that everyone must perform to the best of his ability his own particular part. Then, if the final result is not what had been hoped for or expected, each individual must show good sportsmanship by recognizing that he himself may have been partly to blame and that it isn't always the other fellow's fault.
Understanding Needed
"Now, if an attitude of tolerance and understanding among these crafts can be reached, much will have been done to eliminate this useless charge and counter-charge or buck-passing which serves only to incite further arguments.
"The idea beyond your Projection Advisory Council is an excellent one. Every craft should have an organiza- tion which stands ready to defend its reputation against unjust attack. On the other hand, I hope that the Pro- jection Advisory Council will do just that — that they will defend the pro- jectionist against injustice but will not go further and blame the other fellow for all bad results. I am sure that the intelligence and standing of the men who subscribe to the ideas of your Advisory Council will recognize that in this industry we must all work together to give the public better sound pictures and that if these pic- tures are not better all will suffer.
"So far as the Academy is con- cerned, we would like to impress your membership with one thought, and that is that our interest is in the artistic quality of the product as shown to the public, and the Academy aims to do everything it can to im- prove and better quality standards. Our task is not to represent any par- ticular group, but the common in- terest of the industry as a whole. Our publications, through which in- formation and ideas are cleared, are as open to the projectionists as a medium for dissemination of informa- tion as they are to any other craft. We stand as a neutral organization aiming to bring about better under- standing and better coordination which we are sure will show itself finally in better pictures and greater prosperity for all."
Lester Cowan.
20
Motion Picture Projectionist
November, 1930
Symposium on Wide Film Proportions
By Fred Westerberg
Associate Technical Editor, International Photographer
UPWARDS of 300 invited guests attended the meeting called at Fox Hills Studio on the night of September 17, by the Academy of Motion Picture Arts and Sciences, for the purpose of discussing the wide screen. The gathering was represent- ative of the Hollywood motion pic- ture industry and the exchange of views was most interesting, if not con- clusive. Nugent H. Slaughter, sound expert at Warner Brothers, presided and under his direction the meeting moved off smoothly and without delay.
Douglas Shearer, sound technician and cameraman, spoke on the physical aspects of screen proportion, photog- raphy and sound in relation to a larger screen. He said that the need is not so much for larger figures on the screen as it is for more scope in their movements. He illustrated this by showing a drawing masked to a 3x4 proportion. By removing the mask additional space was shown without affecting the size of the picture. The pseudo-stereoscopic effect obtained on wide film was attributed to the wide angle, of view.
Measuring Grain
Some grain measurements were given. Mr. Shearer found that the average negative of .7 density con- tained 25 silver clusters to each square thousandth of an inch. Posi- tive emulsion was found to have about 4 times as many clusters per unit area as negative film. Negative grain could be reduced, he said, by making a re- duced print on 35 mm. film from a wide film negative.
If reduction prints were made, he said, there would be no need to make provision for a sound track on the wide negative film. This would per- mit a reduction to be made in the total width of the film.
Mr. Shearer doubted the value of a wider sound track than is now used. A gain of 6 decibells in volume would be obtained by doubling the area of the sound track, he said, but the ground noise would also be raised about 4 decibells, so the resulting gain of 2 decibells would hardly be worth the trouble and expense. He also said that the present speed of 90 feet per minute is sufficient to obtain a regis- ter of the highest audible frequencies and concluded, therefore, that any greater speed would be unnecessary. "Wide Film Standards
Dr. Lee De Forrest spoke on stand- ardization of wide film. He reviewed the activities of the sub-committee of the S.M.P.E. on standardization, of which he was a member. He cited some of the dimensions that had been
arrived at from an engineering point of view. He concluded by saying that the committee had gone as far as pos-
"Realife" Wide Film
REALIFE, Metro - Goldwyn- Mayer and Loew Theatres process for securing a wide film image (approximately a 42-foot picture), from standard size film, will be on display at the Capitol Theatre in New York City beginning October 17th. The process will be introduced in other Loew key theatres throughout the country before November 1st. After the pro- cess has been demonstrated for several weeks M-G-M and Loew officials will meet to decide definitely whether the process will be adopted as their official wide film program.
A desire to give the process actual field tests, where the quality of the picture, the functioning of the apparatus and the reaction of the public to the film may be gauged, makes it impossible at this time to secure definite details as to the technical aspects of the sys- tem. Such data as is available was presented in these columns recently under the heading "Wide Film vs. Wide Image on Standard Film," and there is nothing more in the way of con- crete fact which may be had at this time. .
Lester Isaac, Supervisor of Projection for Loew Theatres, Inc., has the following to say anent Realife: "We don't say that we have achieved absolute- ly the last word on the subject of wide film, nor do we say that we are unresponsive to other ideas on the subject. Realife represents some very serious work on the part of both the M-G-M and Loew Theatres technical forces, and it is our plan to first give the system a thorough test under actual field conditions.
"Our future course with re- spect to wide film will be based on the results of this series of tests. Full data on the process will be available when we are convinced that the plan is sound in all respects and merits the serious attention of the in- dustry's technicians. Until that time we prefer not to dis- cuss the Realife system."
sible and that it was up to the pro- ducers to come to some kind of a decision in regard to production re- quirements before any further prog- ress could be made.
Karl Struss, cinematographer, spoke on the significance of screen proportion. He showed that a picture that is not wide enough often appears on the screen as a square due to the angle of projection, and sometimes even as a vertical picture, especially if viewed from the side of the house. Such a picture, he said, is very un- satisfactory from the audience stand- point and is one of the reasons why a wider screen proportion is needed.
Mr. Struss referred to the Gateway Theatre in Glendale, Calif., as an ex- ample of a theatre taking the bull by the horns, as it were, and giving the public a wide screen without the use of a wide film. This theatre, he said, which is typical of 90 per cent of the theatres in this country, simply puts in a matte .500x.800-inch instead of .600x. 800-inch and by changing from a 4^-inch projection lens to one of 3^-inch focal length, obtains a pic- ture reasonably free from grain on a screen 16^x26J4 feet, making full use of the available stage space.
Struss Likes 3x5
Mr. Struss considered the 3x5 pro- portion of this screen as ideal. He pointed out that a 1x2 proportion as used at present on wide film, instead of giving larger full figures on the screen, in this case would present them 20 per cent, smaller since the maximum width of the stage was already being utilized.
Another point brought out by Mr. Struss was that the lack of height of the 1x2 proportion was keenly felt at times in striving for dramatic ef- fect. He cited a case from one of his latest pictures where the headlight of an onrushing locomotive passed out of the top of the screen before the locomotive could get close enough to the camera to obtain the necessary effect.
J. O. Taylor reviewed his experi- ences in photographing six produc- tions on wide film. He was heartily in favor of wide film as it now stands, 1x2 proportion and all. He cited such advantages as finer grain, greater depth of focus, larger figures on the screen and freedom from having to pan the camera.
Max Ree, art director, in speaking of screen proportion, discounted the artistic problem. Audience reaction, he said, must be kept in mind at all times. As an artist he favored the 3x4 proportion as offering the neces-
November, 1930
Motion Picture Projectionist
21
sary element of height and permit- ting a greater concentration of in- terest. But, he said, the possibilities of a wide screen for panoramas and spectacles where concentrated interest is not necessary should not be cast aside.
Suggests Flexible Screen Mr. Ree favored a 3x5 proportion as a maximum in a wide picture. By having a screen of constant height that could be changed in width by the use of nippers he thought a better balance could be maintained between scenes meant to be merely impressive and those which demanded concentra- tion of interest.
Ted Reed, sound expert, eulogized wide film and the 1x2 proportion. He did not believe, as one of the previous speakers did, that action on one side of the wide screen would go un- noticed when important action was in progress on the other side. He said the theatre had mastered this diffi- culty and thought the screen could do so likewise. He found that a wide sound track was a help in recording sound perspective.
Your correspondent was called on for a few remarks and managed to find voice to utter a thought or two on the need of fully investigating the possibilities of 35 mm. film as a ve- hicle for a wide screen picture. He said that area on the film is what we are fighting for in order to reduce the amount of magnification in the projected image. It was his conten- tion that a 3x5 proportion conserves more area than the 1x2 proportion. In closing he expressed the hope that someone would invent a method of removing the sound track from the picture space where it is seriously im- pairing the ability of 35 mm. film to meet the increasing demands being made upon it.
Dr. L. M. Dieterich, scientist and consulting engineer, prefaced his re- marks by saying that wide film is not yet an engineering problem. The first question to study, he said, is the es- thetic reaction of the public. Service to the public demands that they be given a picture at which they will like to look.
Referring to the old masters of painting, Dr. Dieterich said he had found that the best of them found in- spiration in contemplating nature, that consciously or unconsciously they were imbued with the spirit of dynamic symmetry. As evidence of this he pointed to the preponderance of the 1 to 1.618 or the 3x5 rectangle in classic art.
Effortless vision, the doctor said, embraces a field of view in binocular vision of 38 degrees on each side of the optical axis, 15 degrees above and 30 degrees below. In terms of a rec- tangle this gives a proportion of 3x5. In closing, he said that the first prob- lem of wide film is to find a satisfac- tory proportion. Technique can come later.
Sergi Eisenstein, colorful Sovkino
Pres. Wm. F. Canavan, who is represent- ing the I. A. at the A. F. of L. Conven- tion in Boston
director, proved to be the spice of the program. He took it upon himself to rebuild nearly every argument that had been put forth. He was in rare form and his frequent coups were roundly applauded.
A horizontal picture, he said, is only 50 per cent, effective. Agricul- tural and other natural backgrounds require a horizontal picture, but the modern skyscraper needs a vertical picture to do it full justice. A croco- dile, for instance, would also call for a horizontal picture, but a giraffe would certainly need vertical treat- ment as would a giant redwood tree. A square aperture that could be blocked out to any desired shape called for by the scene appealed to Mr. Eisenstein.
He characterized dynamic symmetry as a device to give life to an inanimate painting, but could see no reason for using dynamic symmetry on a screen that already has life and movement. Why use any of the laws of painting in composing a picture on the screen, he contended.
He thought it would be foolish to saddle the industry with a wide film based on the esthetics of the theatre when the screen is still groping for its own esthetics. He is evidently afraid that we are going to have a white elephant on our hands.
In response to Dr. Dieterich's effort- less vision argument, Mr. Eisenstein brought forth the fact that although the eyes move easier in a horizontal direction this is more than offset by the neck, which can be moved more readily in a vertical direction. Mr. Reed broke in to check and double check this statement by demonstrating how easy it is to nod the head and say "yes," especially in Hollywood.
Mr. Eisenstein concluded by saying how nice it would be to be able to play not only with the story and the cutting of the film but also with a screen that could be made to take any desired shape as the story progressed.
Dr. Metfessel, professor of psychol- ogy, was the next to speak.
He questioned the esthetic value of the so-called golden section or 3x5 proportion. An early questionnaire, he said, gave this proportion a vote of 35 per cent, which was more than any other shape received; but Valen- tine in 1900 found in another ques- tionnaire that any rectangle was then considered esthetically sound, except a square.
The doctor brought out the fact that the eye can only concentrate on form near the center of vision, that on the sides it is only sensitive to movement. He also said that we have become so accustomed to stereoscopic vision that we are capable of seeing depth even with one eye under natural conditions. One of these natural conditions is that we do not see things with a border. A large wide picture on the screen, he concluded, approximates natural con- ditions in that we are not so aware of the border.
Dubray Favors 3x5
Joseph Dubray, motion picture en- gineer and erstwhile cameraman, paid tribute in his opening remarks to the Academy of Motion Picture Arts and Sciences for its work in bringing the industry together in a concerted effort to solve the wide film problem.
Mr. Dubray stated he had found an apparent trend in Hollywood toward the opinion that the 1x2 proportion is neither pretty nor desirable. With this opinion he was in agreement. He told that from an engineering stand- point research had proved that film based on a 3x5 picture proportion was more easily handled than film based on a picture proportion of 1x2.
Possibilities of a flexible screen were discounted by Mr. Dubray on account of the control already exer- cised by the cameramen in the use of making pieces on the set and vignettes in the camera. Mr. Dubray heartily indorsed wide film, but stressed the mechanical superiority of a film hav- ing a picture proportion of 3x5.
Some Cost Estimates Mr. Shearer spoke again, saying that any wide film proposals would be subservient to the requirements of commerce.
He cited the fact that it would cost about $40,000,000 to change the pro- jection machines in this country to take wide film and that release prints alone on wide film would entail a cost of about $20,000,000 yearly. Produc- tion costs, he said, would be relatively small. He recommended that consid- eration be given to the idea of print- ing from a wide film negative to standard positive by optical reduction. The results so far obtained were very promising, he said.
In closing the meeting the chair- man, Nugent Slaughter, voiced the opinion that all those who had come with preconceived notions in regard to wide film must have had many of these notions upset.
22
Motion Picture Projectionist
•N
ovember,
1930
As The Editor Sees It
A^J The New Changeover Standard DETAILED exposition of a new changeover standard which becomes effective on November 1 appears elsewhere in this issue and is accom- panied by appropriate supplementary comment on its technical phases. What we wish to discuss here are the broader aspects of the standard and its important bearing on the future well-being of the motion picture industry. From a purely tech- nical standpoint the plan may or may not prove adequate, but this is a point the answer to which will have to await the passing of at least three months. To our mind the most interesting angle to the story of the promulgation of this new standard is not what was done but the manner of its doing.
Having its inception in the Academy of Motion Picture Arts and Sciences, this plan has had the coordinated attention of every technical branch of the industry. Producer representatives, film manufacturers, studio technicians, laboratory workers, exchangemen, exhibitors, and projec- tionists,— all have been afforded the opportunity to express their views on the plan, and the stand- ard finally agreed upon represents the consensus of opinion among these groups. Where is there anyone who can come forward and point to any previous similar occurrence, any such splendid ex- ample of cooperation in the motion picture busi- ness?
We think there will be no answer to this question. Certainly it is a fine thing that millions of dollars are to be saved the industry, that in every theatre in the land a smoother performance will result from changeover uniformity, and that the days of buck-passing in the matter of muti- lated film are definitely behind us. But isn't it a finer thing that at last it has been demonstrated that there can be coordination among the various groups within the industry, each with their own special interests to guard, their own work to be made easier ? We think it is ; and we see in this splendid work among the industry's technical forces an object lesson to the other branches.
Wi
{J Chaos
E thought the high-water mark for stupid- ity had been established in so far as the motion picture business was concerned with the recent muddle over sound picture interchangeability, but we are forced to the conclusion that we were wrong — dead wrong. The present state of affairs in connection with the introduction of wide film — that great big box-office tonic about which pro- ducers talk so much and display such a lamentable ignorance — so far surpasses in degree the sad affair of interchangeability that there really is no room for comparison. Just witness the pres- ent state of affairs in connection with wide film: Mr. X, secure in his position as a motion picture "executive" and inflated to a hitherto unbeliev- able girth by the babel of "yeses" on the part of
his "technicians" (not to mention a covert desire to pep up a falling stock market), — Mr. X has decided to use 70 mm. ; Mr. Y, under the spell of similar influences, is absolutely set on 65 mm. ; while Mr. Z just dotes on 56 mm. But Mr. A is certain that "shooting" on 70 and subsequently reducing the nicture in printing to 35 mm. is the answer to the nroblem; and Mr. B disdains all these processes to further his own idea of merely magnifying a standard 35 mm. image. What does it matter that millions are at stake, and that the answer to the problem may be had as a result of a little hard work? Haven't the Messrs. X, Y, Z, A and B proved their right to be considered modern Merlins — and certainly in "show busi- ness"? Why, of course.
Why, of course not! We are firm believers in the efficacy of teamwork, and we despise chronic knockers, but the present situation with regard to wide film standards is nothing short of disgust- ing. Let it be recorded here in cold type that the aforementioned gentlemen are heading for a fall, and a hard one. Incredible though it may seem, the costly lessons of sound pictures are forgotten — we wonder for how long? The key to the situa- tion is the individual theatre projection room which, as with sound, is expected to produce the answer to all knotty problems — possibly from out of a silk hat. The first consideration should be accorded reproduction, but it inevitably is thought of last. Attachments! attachments! — there is magic in those words for those bedeviled with a knotty technical problem; but just a few more attachments will see the projector collapse of its own dead weight.
What sane influence can be brought to bear to stem this mad rush? Is there no responsible agency within the industry that can assume the task with some promise of success? Or shall we know the answer only when it is too late?
G
<I S. M. P. E.'s 28th Meeting
CONGRATULATIONS on past achievement and well wishes for future progress are in order for the Society of Motion Picture Engineers on the eve of its forthcoming Fall Meeting in New York, the 28th get-together of its existence. Demonstrating its stability in sound achievement, which is reflected in a constantly growing mem- bership, the Society now is truly representative of the motion picture industry with its many inter-related yet diversified fields of effort. It occurs to us that one of the most important func- tions of the_ Society just now is the preservation of its identity as a motion picture technical or- ganization, with motion pictures, per se, its prime concern, and its administration in control of motion picture men. - With this set-up assured, the Society will go far along the road on which it originally set out.
We feel sure that this the 28th meeting of the Society will be equally productive of benefit to the industry as have the preceding conventions.
November, 1930
lYOTION FlCTURE PROJECTIONIST
23
Efficient Sound Reproduction
^^^^^^s^^^^^^^ By R. H. McCULLOUGH -
Supervisor of Projection, Fox West Coast Theatres
THE presentation of "The Big Trail" at the Chinese Theatre, Hollywood, has given new im- petus and added interest to the motion picture industry. For years, motion picture exhibitors, producers, as well as engineers, have had the ideal of a larger projected image, as well as a larger photographed image. Grandeur is double the width of the standard film, which provides a greater scope for group action. The tendency with the 35 mm. film to pack the screen with actors, shoulder to shoulder, has imparted an aggravating monotony to motion picture patrons. Grandeur offers a series of spectacular sur- prises in photography to theatre pa- trons.
The proportion of the Grandeur picture (one to two dimension) is very close to the normal angle of vision, which seems imminent as a standard proportion for the wide film projected image. Grandeur film has an important feature, due to the larger image upon the film and the grain is not so apparent on the screen as it is with the 35 mm. film when projecting Magnascope, which is merely magnification.
Wider Track Desirable
Sound, which has made the motion picture vibrant with music and speech, is greatly improved with the Grandeur sound track, which permits
R. H. MeCulIough
a much greater volume-range in re- cording, and correspondingly greater volume and tone quality in reproduc- tion. A few years ago, when the sound track was added to the motion picture film, it was found that the picture area did not allow enough characters to be included in a scene. To meet this situation and to improve conditions, the Fox Film Company started to work on the development of the wide film, which finally re- sulted in the Grandeur proportion.
Projection offers plenty of difficulty with short throws (distance between the projection screen and objective
Side view of Grandeur projector mechanism. Note the prisms which are mounted
in front of mechanism for the purpose of eliminating vertical distortion occasioned
by the 23° projection angle
lens), when it is desired to obtain a picture of satisfactory width. At the present time, there are no lenses which can be secured under four inch equivalent focal length, which will give satisfactory results with Grandeur.
Special Lens Needed
An ordinary projection lens is en- tirely out of question, except in the longest focal lengths, because of ob- jectionable curvature of field. It is necessary to use anastigmat lenses to obtain good definition, because of the wide angle. It is also necessary that the objective lens rear combination be of sufficient diameter, so as to col- lect the area of light rays from the aperture — otherwise, loss of illumi- nation will result at the sides of the projected image, which will be appar- ent by shadows.
The better the definition of the Grandeur picture, the closer the front seats can be to the screen. If the Grandeur picture image is increased over fifty feet in length, magnifica- tion will result, which will spoil the illusion of objects. Where Grandeur is projected at an angle of more than 15 degrees, it is necessary to use prisms to reduce the vertical distor- tion to a minimum, so as to reduce the elongation of objects, which is very objectionable when viewing the picture from the side seats.
Problem of Illumination
It is imperative that the Grand- eur screen be well illuminated. At the present time, there are no car- bons manufactured to permit using over 170 amperes at the projector arc. Approximately 13 foot candles of illumination is required for satis- factory projection. Super-Hi-Inten- sity Lamps must be used to obtain the correct amount of illumination. With the Grandeur aperture 1.768 x .885, and by using the ordinary 4% in. plano-convex condenser combina- tion, the illumination area is greatly reduced when the area of the aper- ture is circumscribed.
It is obvious that if the same amount of light, which passes through the aperture in an ordinary projector, be spread over a screen area twice as large the screen illumination would only be half as great.
One obvious means of increasing- the illumination is to employ con- denser lenses of larger converging angle. About 25 per cent more il- lumination can be obtained if the rear condenser lens (next to arc), has a cylindrical surface. Such a condenser will yield an elongated spot of light
24
Motion Picture Projectionist
November, 1930
equal to that of the rectangle, with- out loss of light.
It has been indicated that the rela- tively enormous picture on the screen may prove more satisfactory at a level of brightness lower than we have been accustomed to with the standard picture size — however, with the facts at hand concerning this mat- ter, the requirements for illumination of the Grandeur picture is similar for the illumination required for the standard size picture.
Fader Contacts
One of the most important points of the sound reproducing system is the fader or in other words the vol- ume control. When it is realized that a resistance of thousands of ohms is required for distortionless volume control, and that an amplification of thousands of times takes place be- tween the circuit and the powerful loud speakers, it stands to reason that the slightest uncertainty of contact causes tremendous noises.
Fader contacts should be inspected quite frequently. When fader con- tacts become dirty, noises will be per- ceptible on change-overs, and when increasing or decreasing the volume. Clean fader contacts with a soft rag dampened with carbona; and after cleaning they should be polished with embossed paper and a very small amount of vaseline applied to the con- tacts, which will help ease the opera- tions and besides will help to keep the contacts from becoming corroded.
41-A Amplifier
The 41-A amplifier is a first stage or speech amplifier with the filaments of three 239-A vacuum tubes con- nected in series. If this amplifier ceases to function, one of the first things to look for is a burned out vacuum tube. A gain control is in- serted across the secondary of the imput transformer, the variable arm of which is connected to the grid of the first 239-A tube.
A second means of controlling the gain of this amplifier is inserted in the grid circuit of the second tube. The filament current value should always be approximately 270 milli- amperes. Very little trouble has been encountered with this amplifier. How- ever there are a few things which I do believe every projectionist should be familiar with to locate certain troubles. The voltage supply for the plate circuit is obtained from the 42- A, which is the following amplifier, and which has its own rectifier.
239-A Tube Test
The 239-A vacuum tubes which are employed in the photo-electric cell and 41-A amplifier can be tested in the first socket of the 41-A amplifier. Before testing these tubes, be posi- tively sure that all currents and volt- ages of the system are adjusted to their normal operating values. Place the tube, to be tested, in the first . socket of the 41-A amplifier. Press -the plate current button and vary the
Believe it or Not —
Censorship deletions on film- disc releases make possible the recording of this new demon- stration of managerial deference to the almighty projectionist. At the Fox Japanese Garden Theatre in New York were re- ceived recently several disc re- leases the reproduction of which was marred by censorship cuts, which means of course the bringing down of the fader on those portions of dialogue which are considered objectionable. This means action but no sound.
Greatly perturbed at the pros- pect of much unfavorable criti- cism accruing to the theatre's projectionists as a result of these vocal lapses, assistant manager A. B. Daniel went into a huddle with manager J. Sal- mon (their names really deserve to be printed). Result: just be- fore that particular subject was screened Mr. A. B. Daniel ad- vanced to the stage and assured the audience that the defects in reproduction were no fault of the projectionist but were the result of censorship deletions!
One gold medal, please.
filament current, between the limits of 220 milliamperes and 270 miliiam- peres. Any 239-A tube falling below 1.3-5 or beyond 1.6-5 milliamperes should be replaced.
A 21 CB 1 microfarad condenser, identified as C-ll, is placed across the 390 volt leads (the rectified plate sup- ply from the 42-A amplifier to the 41-A), and also a 109-B choke coil identified as LI is connected in series with the positive lead. If condenser Cll should become shorted, no plate current could be obtained at any of the tubes. A likewise result will be encountered if choke coil LI becomes shorted.
Should the supply plate voltage be above 390 volts, a high plate current reading will result — if below, a low plate current reading will result. If the plate current of any individual tube varies above or below the nor- mal operating values, replace it with another and if the values are still off, the trouble can be traced to one of the component parts or the wiring.
Condenser Troubles
The inside of filtering condensers, such as is used in sound reproducing equipment, consists of many layers of aluminum sheets spaced with tissue paper. I have found that excessive temperature will cause these conden- sers to dry out, which on a few occa- sions have resulted in not properly filtering the rectified current, and a hum was encountered. Upon replac- ing the condenser the hum was elimi- nated.
An open circuit in any of the grid circuit stages in this amplifier will cause a hum, which will be very per- ceptible in the reproduction. A shorted condenser between the plate of VI and the grid of V2, or a shorted condenser between the plate of V2 and the grid of V3 will cause this trouble. Should CI condenser become shorted, the plate current reading on the VI tube will be exceedingly high.
"B" Batteries
The problems and troubles encoun- tered with dry "B" batteries have been mentioned in preceding articles. A theatre recently ran the show on one projector because crackling and popping noises were encountered with one of the photo-electric cell ampli- fiers emanating from a defective "B" battery. I have pointed out many times the troubles which can be ex- pected from dry "B" batteries. Noises, such as crackling and pop- ping, may be attributable to a poorly soldered joint between the cell con- nectors and cell terminals. This trouble may even exist in a new bat- tery used only a few hours, which was still in good condition when tested by the projectionist.
Noise in "B" batteries can also be caused by fluctuations in voltage, re- sulting from poor or defective cell in- sulation. Leads attached to the spring terminal clips, at the top of the dry "B" battery, should always be soldered, so as to insure a good tight connection at this point. There is positively no excuse for running the show on one projector when one photo-electric cell amplifier is in good condition.
Have Pair of Leads
A pair of leads should always be kept on hand with small spring clips, and a small cut-out switch, so that a temporary hook-up can be made from one photo-electric cell amplifier to the other. It should be remembered that two photo-electric cells can be used when one P. E. C. amplifier is in good condition, and that a continuous sound-on-film show is possible. Long waits and interruptions must be avoided.
Warner Wide Film Head
Warner Brothers engineers have about completed work on the new wide film projector head on which they have been experimenting for some time past. Like the new Grandeur apparatus, it permits use of both wide and 35 mm. film. The changeover on the Warner machine can be made in a matter of a few minutes merely by switching the aperture plate and lens.
"Vitascope" Trade Name The Warner projector for wide film is contained entirely in a specially designed head which replaces the 35 mm. head now in use. It is the in- tention of Warner Brothers to market it under the trade name of "Vita- scope."
November, 1930
Motion Picture Projectionist
25
Why and How of Continuous Projection
Continuous projection has been little more than a phrase heretofore in the motion picture industry, but in this the third of a series of articles on the subject Mr. Holman explains the why and how of this most interesting of projection topics and brings into bold relief many points heretofore treated only in the vaguest manner. We consider Mr. Holman's contribu- tions on this sxibject a most valuable addition to motion picture technical literature. — The Editor.
THE term "continuous projec- tion" is applied generally to any process for exhibiting motion pictures which does not require intermittent movement of the film. That is to say, any projecting device, provided either with variable reflect- ing or refracting elements, which functions with a continuous movement of the film across its aperture plate, is nominally considered a continuous projector regardless of whether it may require a shutter to cut-off travel ghost during all or part of the transi- tion. As a matter of fact, the real criterion for continuous projection is not, per se, continuous film movement but rather continuous non-periodic screen illumination, and this can be provided only by complete elimination of all shutter effect. It is evident, therefore, that the main purpose of continuous projection is to completely eliminate the shutter, for herein lies the chief advantage of non-inter- mittent projection. Strictly speaking, no device should be classified as a con-
By Arthur J. Holman
tinuous projector unless it provides a transition between film frames which is so exactly correct that it does not change the intensity of the screen illumination or mar the definition of the screen image.
It is not difficult to see how a mirror system might be capable of meeting these requirements, at least in theory, provided it were possible to secure the exactly correct orientation of the mirrors throughout the com- plete picture cycle. On the other hand, the theory of the movable lens system is less obvious, so it will be the purpose of this article to describe how and why it functions. Once the basic principle is understood, the modus operandi of the lens wheel system is as easy to visualize as that of the mirror system.
Lens Characteristics
We will begin the analysis by re- viewing a little physics. Any homo- geneous transparent substance having a pair of opposite highly polished spherical surfaces is called a lens. In motion picture work, all lens are made of optical glass. Lenses are classified as positive or negative ac- cording as they are thicker at the middle or at the periphery, regardless of the curvatures of their surfaces. On looking through any lens held at arm's length, or whatever distance is necessary to get a good focus, at some horizontal line such as a window sill or the roof of a building, one im- mediately observes a very important characteristic of all lenses. If the
Fig. 1 — Front view of mechanism with cover plates removed, showing lens wheels, hrake wheels, balanced drag mechanism, and mount for front elements of objective
lens is held at its top and bottom edges in such a manner that the hori- zontal line under observation is visible to the eye beyond each side of the lens as well as through it, it will be noticed, on moving the lens up and down slightly, that there is one posi- tion in which the horizontal line will appear straight and unbroken at the edges of the lens.
If a positive lens, thus held, is moved slightly downward, the portion of the horizontal line visible through the lens will appear to be elevated, and if the lens is moved upward, the line will appear to be depressed. If the lens is negative, the apparent dis- placement of the line is in the direc- tion the lens is moved, but, in any case, the apparent displacements are proportional to the movement of the lens. When the horizontal line, visi- ble beyond each edge of the lens, appears unbroken at the edges of the lens, the line appearing in the lens passes through a very interesting and important point called the optical center of the lens.
To state the law of physics govern- ing the case ; there is no apparent dis- placement of a line when it is viewed through the optical center of the lens, but when viewed through the lens in any other position, its apparent dis- placement is proportional to the dis- placement of the optical center of the lens from its centered position on the line. In other words, any lens pro- vides a prismatic or bending effect which is directly proportional to the decentration of the lens. This law has been known to opticians for many years and the principle has long been applied in spectacle work. It is in- teresting to note that this funda- mental characteristic of all lenses is the basic principle whereon the re- volving lens wheel system of con- tinuous projection operates.
When this characteristic of a lens is fully realized, it is not so difficult to understand that it might easily be possible to so move an objective that a stationary screen image could be obtained from any one film frame moving across an aperture plate pro- vided the required relationship be- tween the film frame movement and objective movement was maintained.
The first thing to be noted, is that the film frame movement and the ob- jective movement are, in general, along a straight line, i.e., there is no turning or twisting movement in- volved as is the case with a mirror system. Moreover, if it were possible to bring along a complete objective with each film frame as it crossed the aperture plate, and each new objective coming into action was so aligned that
26
Motion Picture Projectionist
November, 1930
it would exactly superimpose the image of its respective film frame upon the image of the film frame pre- ceding it across the aperture plate, it is not hard to see that it might be possible to accomplish the transition between film frames without using a shutter. But such a series of com- plete objectives would necessarily be small in diameter and therefore, could not possibly transmit the required screen illumination, moreover the sup- porting structures themselves would act as shutters as they crossed the light beam transmitted through the film by the condenser system. Inven- tion was required to make practical application of the principle.
Other things being equal, objectives transmit light in proportion to their / values — i.e., focal length divided by effective aperture — hence any new objective system, if it is to have equal light transmitting efficiency, must be capable of working at the customary effective aperture. Incidentally, this involves one of the most difficult problems that a continuous projector designer has to face. Fortunately, however, it is possible to get the full effect of the basic principle by mov- ing only the rear elements of the ob- jective, the front element remaining stationary on the principal axis of the projector. This arrangement not only provides normal light transmitting efficiency but also makes it practical to eliminate all shutter effect due to supporting structures.
It will be observed from the accom- panying illustration (Fig. 1) of the mechanism, that the lens elements on the lens wheels are so shaped and supported that, as the lens wheels rotate, no opaque structures (except- ing the very small opaque patches over the outer radial edges), traverse the light beam which is transmitted through the film by the condenser system.
The relative refractive powers of the front and rear elements of the objective, as well as their relative positions with respect to the aperture plate, are determined by known physical laws which must be satisfied in order to secure exact superimposi- tion upon the screen of images of adjacent film frames during the transition. The dissolving action, taking place during the transition, occurs in the following manner. In- asmuch as the dissolve occupies a large portion of the picture cycle, it is necessary that the aperture in the aperture plate be approximately three frames high and the condenser system must be so designed that the elongated aperture is not only fully and uni- formly illuminated without excessive loss of light on the sides, but in ad- dition, all light passing through the aperture must converge into a beam of relatively small circular cross-sec- tion where it passes through the re- volving lens wheels.
Let us consider first the instant when a film frame is exactly centered (Continued on page 31)
Sound Projection Defects
Listed below are major sound projection defects which are occurring in Publix Theatre operations every day. The cor- responding causes are given. Remedies are obvious. They should be applied at once wherever defects exist. Such an im- portant phase of successful theatre operation must be care- fully handled at all times.
I. To avoid interruptions, the re-
sult of defects insists on cleanliness in:
1. Fader
2. Exciting lamp
3. Photo-electric cell
4. Batteries
5. Sound gate, etc.
II. Common defects and their
causes:
1. Flutter (undulating sound)
Causes
a. Dirt on sound gate
b. Worn sound sprocket
c. Bad record (warped, etc.)
d. Oil on sound track
e. Dirt on sound sprocket
f. Failure to close 1A unit door
g. Slipping of lower magazine take-up
h. Film tension pad out of ad- justment j. Turntable out of alignment k. Loose take-up chain
2. Loss of Volume
Causes
a. Dirty optical train lens
b. Blackened exciting lamp
c. Sagging filament in exciting lamp
d. Defective photo-electric cell
e. Soft tone needle used
f. Worn record
g. Thumbmarks on PEC win- dow or exciting lamp
h. PEC window out of line
j. Exciting lamp filament out
of focus k. Current on exciting lamp
too low.
(Step up current on rheo- stat) 1. Low B battery voltage m. Dirty sound aperture n. Defective tubes o. Dirty contact points on
fader p. Bad connecting plugs to horn
units q. Disconnected plug at horn
units
3. Bell Noises:
Cause o. Defective microphonic tube (test with fingernail)
4. Hum:
Causes
a. Frame of projector not grounded
b. Motor control box not grounded
c. A.C. lines too close to speech units
5. Periodic Sound:
Causes a. Warped record
b. Dirt on turntable
c. Turntable out of line
6. Ripping Sound : Causes
a. Needle jumps groove
b. Dirt on record
c. Cut grooves in sound track
d. Loose wires at connections
7. Off Pitch Sound:
Causes
a. Running above or below syn- chronized speed of 90 ft. per minute
b. Dirty contact on machine motor commutators
c. Defective tubes in control box
8. Crackling, Frying Sound:
a. Defective tubes, exciting lamp, PEC
b. Defective batteries
c. Dirty battery terminals
d. Loose connections
e. Vacuum tube loose in socket
f. Dirt on end of lens tube
g. Dirt on sound track
9. Overload Distortion :
Causes Excessive volume caused by:
a. Gain control out of order
b. Fader setting too high
10. Out of Synchronism:
Causes
a. Improper loop
b. Improper framing at start (disc)
c. Improper reproducer position at start (disc.)
d. Reproducer arm stuck at holder
e. Failure to insert proper number of frames of blank film (disc)
f. Record not clamped on turn- table
11. Motor Boat Sound:
Cause a. Improper adjustment of film guide roller
12. Change in Pitch at Change-
over:
Cause a. Defective motor box control
13. C h a n g e in Volume at
Changeover: Cause
a. Attenuators improperly bal- anced
b. Exciting lamps or PECs not matched
VOLUME TOO LOUD OR TOO WEAK IN CERTAIN AREAS INDICATES WRONG HORN POINTING.
November, 1930
Motion Picture Projectionist
27
New Power's Front Plate with Lateral Lens Adjustment
TO fill a long felt want on the part of the users of Power's Projec- tors, thousands of which are equipped with some type of sound equipment, the International Projector Corpora- tion takes pleasure in announcing two new assemblies which greatly facili- tate the manipulation of lenses and apertures and, consequently, make for a marked improvement in projection where Power's Projectors are used.
The Power's front plate assembly shown in the accompanying cut is de- signed along the lines of the former type which has given universal satis- faction wherever used, but many fea- tures have been added thereto which will at once appeal to the projectionist as a marked and up-to-date improve- ment in construction.
Instantaneous Change Possible
Practically an instantaneous change of lenses is now possible with this new unit, and a lens centering device has been added, making it possible to cen- ter the projected picture on the screen when sound-on-film is used. The in- stantaneous lens change feature al- lows the use of the proportional type aperture plate and a shorter focal length lens so that the projected pic- ture with sound-on-film may be in- creased in dimensions to meet the di- mensions of the silent or sound-on- disk prints.
Another excellent feature of con- struction, which will appeal to all progressive projectionists, is the elim- ination of the old type rack and pinion lens focusing adjustment and the sub- stitution therefor of the micrometer type of focusing pinion which allows
the accurate adjustment of the lens and eliminates the possibility of the lens jarring out of focus at any time during projection.
A new type framing lamp assembly has been incorporated in this new de- vice and which may be instantly re- moved for lamp replacement when necessary. The pull chain for the lamp socket is readily accessible to light the framing lamp when thread- ing the projector.
A reference to the lettered photo- graph, Figure 2, in connection with the following data will explain the operation of this equipment.
A is the front plate which attaches to the Power's mechanism in a similar manner to all previous types.
B is the lens mount and focusing assembly attached to the front plate A.
Lenses are securely clamped in this mount by locking screw C.
D is the lateral lens adjustment by means of which the picture is cen-
Figure 1
tered on the film and screen when changing from silent or sound-on-disk
909 915 4
1-908
Figure 2
to sound-on-film with either the pro- portional or regular sound aperture.
E is an adjustable stop for deter- mining the lateral throw of the lens. This stop is adjusted when the instal- lation of the assembly is made and remains fixed thereafter for any given focal length of lens. The two. knobs F are attached to the microm- eter focusing device and, as will be noted, may be operated from either side of the projector.
G is the pull chain for the framing lamp and H is the framing lamp as- sembly latch, one of which is attached to either side of the assembly so that the instant removal of the framing lamp assembly may be readily accom- plished without interference with any other part of the unit.
Figure 1 shows a fixed focus collar,, similar to that used on the Super Simplex Projector, by means of which lenses may be instantly snapped into focus where quick lens changes are necessary.
The hole G, Figure 1, in the collar slips over rod J, Figure 2, and thereby accurately locates the lens rotation- ally so that the picture is always in the same place on the screen regard- less of how many times the lens may be removed and replaced.
Where lenses do not project far enough beyond the lens mount B to allow this fixed focus clamp may be readily attached, many of the lens ex- tension attachments used in connec- tion with lenses on Super Simplex Projectors may be used. Data on these various assemblies will be furnished on request.
Power's Aperture Change As- sembly for Sound Projection
This new assembly is shown in Fig- ure 3 and very little explanation is needed to convince the projectionist that he can work far more efficiently with this assembly attached to his Power's Projector and particularly
28
Motion Picture Projectionist
November, 1930
when it is used in connection with the new front plate assembly previously described.
A shows the front view, B the end view and C the rear view of this as- sembly. It may be readily attached to all existing Power's Projectors as may the Power's front plate assembly. It has been so designed that it may be readily used in connection with the Power's old type gate although it ob- viously would be more efficient when used in connection with the Power's new style gate assembly, data cover- ing which may be obtained from any office of the National Theatre Supply Co. or direct from the factory at 90 Gold St., New York City. This aper- ture assembly is furnished with the standard silent or sound-on-disc aper- ture and the standard sound aperture or the proportional type sound aper- ture as desired. Complete instruc- tions for attaching it to Power's Pro- jectors are furnished with each assembly, and it may be easily at- tached by the projectionist in the space of a few minutes.
The aperture plate in the assembly
slides vertically in two guides and is rigidly locked in whichever position it is being used. A slight pressure on locking spring D with the thumb and a downward pressure on lever E with the forefinger brings the sound aper- ture into position.
When the sound-on-disc or silent aperture is desired, all that is neces- sary is simply to push up on lever E, no pressure then being required on locking spring D.
When using the proportional aper- ture it is necessary to change lenses or use lenses of the bifocal type so that a shorter focus may be obtained in order to bring the projected picture up to the standard size of the picture projected through the silent or sound- on-disk aperture.
These two units will undoubtedly appeal to every projectionist and no time should be lost in equipping exist- ing projectors with these modern means of acquiring superior projec- tion and, incidentally, eliminating a great deal of the inconvenience for- merly experienced where sound-on- film and sound-on-disc is used.
Rest and Relaxation
By H. E. Kleinachmidt, M. D.
OF the many remedies in Nature's medicine chest, the commonest, and perhaps the most useful, is rest. Almost all disorders of the body make us feel "sick" and warn us to lie down. Sometimes, the demand for rest is so insistent that we are over- powered by unconsciousness, but more often the hint is a more gentle one which we too often tend to disregard. For example, people speak of "fight- ing a cold," by which they mean keep- ing up their usual activities to the last ditch. It is not inconsistent nor a surrender to fight a cold by resting, for by so doing we conserve bodily energy which may then be spent in overcoming the germs that are caus- ing the cold.
Tuberculosis is one of those diseases that responds to rest. Here, two factors play a part. The lung tissue is diseased; it needs rest to recover. But every motion of the lung stirs up the injured tissue. Exercise, mental labor, emotional stimulation, in fact, anything which speeds up bodily activity increases the work of the lungs and thus gives them no chance to heal.
The other factor has to do with what is called intoxication. In tuber- culosis, as in many other diseases, certain poisons are excreted by the diseased tissue. These poisons, or toxins, are absorbed into the blood and give rise to fever, exhaustion, lack of appetite, discomfort, and other distressing symptoms so well known to the consumptive. Every activity of the body increases this absorption, while complete bodily rest lessens it
and so gives the entire body a chance to increase its healing powers. Ex- perience backed by sound science has taught us that rest of body, mind, and emotions, as nearly as that is possible, is the most necessary element in the cure of tuberculosis.
Proper Rest Most Important
Even in early states of the disease, comparative rest is the best method we know of to prevent its further progress. There are many children whose lungs have been invaded by the tubercle bacillus and who have suf- fered some slight damage — so slight, in fact, that there are no symptoms and the child may appear as healthy and rosy as any other. Only by means of the tuberculin test and the X-ray, which pictures the slight damage, can the diagnosis be made.
These children are not sick in the usual sense, but if, as they grow older, they are subjected to strain, the re- sistance of the body, which has thus far held the disease in check, may be so depleted that the sparks of the disease are easily fanned into a flame and then consumption develops. That happens frequently during adoles- cence, when parental control is less- ened, when boys and girls become ab- sorbed in their studies and sports and dances, and when the rapid transition from child into adult makes unusual demands on the body.
Xmas Seals Pay the Bill
Tuberculosis associations through- out the country have this year, by means of a vigorous campaign, brought to the attention of parents
and teachers the necessity of finding out whether the sparks of the disease are already in the young child's body. During 1931, these associations pro- pose to follow up this good work by bringing to the attention of older boys and girls and their elders the danger of overstrain, especially to those youngsters who already have the germs in their bodies. The slogan of this campaign will be, "Tuberculosis, the Foe of Youth." Posters, leaflets, motion pictures, lectures and numer- ous other means will be employed to sound this note. The work is to be financed by the sale of Christmas seals.
Cost to Wage Earners
According to a survey made by the U. S. Bureau of Labor Statistics a few years ago, two per cent of the American population is sick at any given time. The cost of this sickness aggregates the total of more than two billion dollars every year.
Since this survey, another made by a life insurance company shows that approximately $80 per year is spent by each wage-earner's family as the cost of sickness. This amount would not seem to be excessive — if it could be safely assumed that eighty dollars would cover the cost of all sickness from which the family might suffer. Unfortunately, no family can arbi- trarily fix any given sum to be spent. Ill health and its attendant medical attention may not be the only items to make inroads upon the family's "sick budget." A large dental job may present itself; a major operation may suddenly be required, or a con- tagious disease may infect some or all of the family — then where does the eighty dollar budget come in?
An average of $80 for a sick budget represents a combination of larger and smaller amounts that vary from next to nothing to thousands of dollars per year. So long as sickness expendi- tures do not exceed the eighty dollars, so long can the budget hold its own. When it exceeds that amount trouble begins — for that family. They are either forced to go into debt, or accept charity. The latter is something no- body cares to do, so it often happens that the family resort to quackery, patent medicines or do without medical attention entirely.
20>Year Records of Progress
Tuberculosis, alone, is responsible for a death rate that is from eight to twelve times higher among certain industrial workers than it is among farmers, for example. As menacing as these figures sound — and, in re- ality, are— the tuberculosis death rate has been declining since those statistics were compiled a few years ago. It is still altogether too high, (79 out of every 100,000 persons) and tuberculosis still kills more persons between 18 and 40 than any other disease. At the same time, the rate has been cut in half in the last 20 years.
November, 1930
Motion Picture Projectionist
29
Review
Our Review Department inaugurated with the last issue met with a fine reception on the part of our readers and elicited much correspondence sug- gesting matter for review. It is our intention to include a wide variety of topics in this department with sound pictures to receive its due share of atten- tion but no more. Some readers were under the erroneous impression that this department would be devoted exclusively to sound picture data, but this month's department will serve to dispel such thoughts. Film mutilation is a pertinent topic just now, and because of the elementary nature of the infor- mation presented this month we feel that it will be very welcome. — The Editor.
How to Prevent Film Mutilation
By Eastman Kodak Company
EVERY year the loss through needless film mutilation runs into staggering sums and of course someone has to pay the bill. There are several contributing causes to this waste, as will be pointed out in the pages that follow, and it is with the frank purpose of giving projec- tionists helpful facts with which they may not be familiar that this paper was prepared. Needless film mutila- tion may be caused by defective manu- facture, faulty laboratory methods, poor inspection in the exchanges, care- less handling in the projection room and worn or imperfectly adjusted pro- jection machines, and, while it is diffi- cult in many cases to fix the exact responsibility, each possible source of damage will be fully discussed.
The Film
The film can be blamed only when the manufacture is defective. The base or support of motion picture film, which is of standardized thickness, is made from cotton and with reasonable care will fulfill the requirements of commercial use, but due to the nature of its origin consideration should al- ways be given to the fact that it has physical limitations. The Eastman Kodak Company, with its years of ex- perience in the manufacture of motion picture film, quite naturally observes every possible precaution to assure it- self that the quality of its product is kept uniform. Samples from all coat- ings are thoroughly tested for their photographic and physical properties and must pass careful scrutiny of in- spectors whose sole duty it is to find flaws or imperfections.
The matter of accurate perforating is of the utmost importance and is only accomplished by constant vigi- lance on the part of experts to keep the machines at the highest degree of precision. Recent changes in the per- foration dimension of Eastman posi- tive film was adopted only after exhaustive practical tests had proved its greater endurance and wearing properties.
As a final check against photo- graphic quality and physical charac- teristics, test lengths are run through regular commercial projectors, under
exactly the same conditions as would be encountered in the theatres.
The Laboratory
Improvements in equipment and methods of manipulation in all the important laboratories have reduced the possibility of affecting the physi- cal properties of the film during the printing, developing and finishing op- erations to an extent as to be almost negligible.
The Exchange
Investigation of the general pro- cedure in the inspection and repair of prints indicates that a considerable proportion of the burden of print mu- tilation begins in the film exchanges. It is not so much that the exchange starts the damage as that it fails to stop it. Inspections are invariably too rapid to be thorough. Splicing is carelessly done with the result that the films are frequently sent to the theatres in such poor condition as to be unable to withstand ordinary pro- jection, to say nothing of the super requirements, particularly with re- spect to high speed of projection and rapid rewinding, which are all too frequently the case. In rewinding, care should be taken to see that the "rewind" is properly lined up so that the film will feed from the one reel to the other without striking the edges of the reels. The use of defective reels caused untold damage in the re- winding operation. Cinching occurs
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Fig. 1. The full hole splice generally recommended
when the person rewinding attempts to tighten the roll. This causes scratches on both sides of the film.
Cupping the film to detect damaged edges, perforations, or loose splices is very apt to crack or split the film, more especially on subjects which have had repeated projection on pro- jectors using high amperage. Careful inspection and repairs in the ex- changes will result in better service to the exhibitor, eliminate breaks which are the frequent cause of film damage, reduce the amount of replace- ments due to breakdown, and make the subjects available for constant service. Longer commercial life means increased earning capacity.
The Exhibitor
Good projection is entirely depend- ent on the skill of the projectionist and the condition of the film and the projection machine. Through con- stant use projection machine parts become worn and out of adjustment. Projectors should never be permitted to get in this condition. Replacement parts are readily available and for the most part inexpensive, and any ex- penditure in this connection will im- prove projection and materially help in the reduction of unnecessary film loss.
Careful study of the following will be helpful to all concerned with mo- tion picture film.
Splices
Splicing, whether done in the film laboratories, film exchanges or pro- jection rooms, has such direct bearing on the welfare of the film as to call for special and constant attention.
Much film is ruined by poor splic- ing. Splices that are wide, stiff, buckled and out of line cause the film to jump the sprockets resulting in torn perforations or breaks. Perfora- tions in the vicinity of a splice of this kind will always be found to be strained or broken out. Stiff and buckled splices are caused by exces- sive scraping of the film, or a too lib- eral application of cement or both. The use of a poor quality cement re- sults in. splices pulling apart espe- cially in the film gate or trap. This constitutes a hazard; therefore, all weak or otherwise bad splices should be remade before projection. Figure 1 shows the well-known full-hole splice which is the most widely used and if properly made gives the best all- around results.
Pamphlets on splicing instructions may be had without any charge on application to the Eastman Kodak Company, Rochester, N. Y.
Whenever film is damaged on a pro- jector, it is generally customary to lay the cause of the trouble to one or more of three different things: namely, sprockets, idlers, and tension exerted on the film by the springs in the gate or film trap.
While it is true that in most cases the trouble can be traced to one or {Continued on page 39)
30
Motion Picture Projectionist
November, 1930
e Laboratory
Light Sensitive Cell Nomenclature
A JOINT committee of representatives of Institute of Radio Engineers, Westinghouse Electric & Mfg. Co., Bell Telephone Laboratories, and General Electric Com- pany are reported to have finished their work in connec- tion with light sensitive cell nomenclature and have decided upon the use of the word "phototube" as expres- sive of the photo electric cell. This action is perfectly all right as far as it goes, but to this writer's mind, at least, the term is hardly suitable as standard nomenclature for all light sensitive cells, since it apparently refers only to that specific type of cell which gives what is known as the "Hallwachs effect," i.e., electronic action as a result of light.
It is commonly known that there are other types of light sensitive cells, and while they do not belong to the electronic group it cannot be denied that they function as a result of light falling upon them. In addition to the photo electronic group there are (1) the photo conduc- tion family, of which selenium is a very prominent mem- ber and the sulphides and oxides of the metals, etc., and (2) the type which embodies the so-called Becquerel effect in which a chemical action is the result of illumination. This latter form is commercially known as the photo voltaic cell.
My contention is that the action of the standardization committee above referred to is hardly in keeping with a wholly desirable forward-looking outlook on progress within the art, since the use of the word "phototube" im- plies a limitation of work in the art to the vacuum or gas- filled types of cells.
When one recalls the splendid work accomplished in the light sensitive field by workers in other than the vacuum and gas-filled fields the shortsightedness and unfairness of the new standard becomes apparent.
While the term "light sensitive cell" covers the entire phenomena of light action on the metals and compounds — including all three types : photo electric, photo conductive, and Becquerel effects — a non-descriptive term should be applied as a family name with further subdivisions to be classified according to their true nature.
•Conducted by SAMUEL WEIN-
A New Type Exciting Lamp
DR. J, W. MARDEN of the Westinghouse Electric Co. announces a new type of lamp, in which an abun- dance of ultra violet rays emanate. The lamp is intended for subjecting human beings to artifical sun, and so stimu- late blood circulation below the skin, etc. The lamp has a rating of 25 watts, i.e., 20 volts at 1.25 amperes. The physical dimensions of the lamp are that of the conven- tional incandescent lamp.
Just why such a lamp cannot be used as an exciting lamp is the concern of the present article. It seems logical, that any source of illumination so rich in ultra violet rays, and with such a low rating, would find immediate applica- tion to sound motion pictures, particularly as an exciting lamp.
Rich in Ultra Violet Rays
It will be remembered that the greatest flow of photo electrons are had on exposing the photo-electric cell to a rich source of ultra violet rays. Such being the case, a larger number of photo-electrons ought to flow as the result of exposing the cell to the lamp devised by Dr. Marden. A decided advantage of a greater photo-electron
flow is that less amplification would be necessary, and, ac- cordingly, less distortion would result.
It is hoped that Dr. Marden will take our suggestions in this respect, and adapt his lamp particularly to ac- commodate the requirements for sound motion pictures, and thus aid development in the art.
Use of Battery Eliminators
THE elimination of batteries, and the attendant care, is the subject of considerable experimental investi- gation by a number of investigators. By elimination of batteries is meant the adaptation in the circuit of a device which gives a D. C. potential without any "ripple" — in simpler terms, a rectified A. C. potential.
There is available today several types of rectifiers which can be used in the projection room: (1) the electronic tube, in which a filament and plate are used (diode tube), with a trace of an inert gas, and (2) the crystal recti- fiers, i.e., the oxides or sulphides of the metal and in par- ticular, the sulphides or oxides of copper. As might be expected, each of these rectifiers have their own particu- lar advantages.
It is possible to design at the present time a rectifier giving extremely heavy potentials, sufficiently high to function the A, B, or C potentials of an amplifier circuit, or to operate the "exciting lamp" circuit, etc. All that is required is the proper capacity rectifier unit, and a suitable capacity and inductance in the circuit to "smooth out the ripple" of the "raw D. C." so formed by the recti- fier. Proper shielding of the rectifier is another requisite.
Here is a list of manufacturers making rectifier units who are in a position to give detailed information con- cerning the proper number of elements, capacity of con- densers, and inductance characteristics:
Forest Electric Corp. Newark, N. J. Tube types
Elkon Works, Indianapolis, Ind. Copper sulphide units
Westinghouse Elec. & Mfg.Kodel Elec. Mfg. Co.
Co. Cincinnati, Ohio
East Pittsburgh, Penn. Copper oxide units
Copper sulphide units
B-L Electric Corp. St. Louis, Mo. Copper sulphide units
Anti-Vibration Material
ALL projectors, be they stationary or portable, have a tendency to vibrate, and these vibrations are picked up by the sensitive sound amplifiers and these in turn are heard by the audience. Various methods of compensating for vibration have been resorted to, particularly the suspension of the sensitive devices by heavy springs, elastic bands or flexible plates. Other methods employ rubber or felt padding with good results.
There has been submitted to us for approval "Keldur" a synthetic rubber for anti-vibration purposes. The physical appearance of the compound is sort of a black or dark brown gelatinous mass, and is cast between two course woven material. This material can be had in sheets 26 inch by 36 inch by % inch thick.
We have tried this material out with good results, and it is hereby recommended to those projectionists who are experiencing difficulty as a result of vibration.
November, 1930
Motion Picture Projectionist
31
Continuous Projection
(Continued from page 26)
on the aperture. Assuming that the screen image is in frame, the optical centers of a pair of lens wheel ele- ments will also lie on the axis of the front element of the objective, there- fore, at this instant, we have a centered system which is comparable, in all respects, to any ordinary pro- jection objective. In this position of film and lens wheels, the light reach- ing the screen is supplied through the single frame centered on the axis, which we will call frame No. 1.
As the film moves downward across the aperture, and the lens wheel ele- ments rotate downward at the re- quired proportional rate, the screen image of this frame No. 1 remains stationary, and of full intensity until such time as the succeeding pair of lens wheel elements enters the light beam. As the radial line between lens wheel elements enters and passes through the light beam, the image of film frame No. 1 decreases in in- tensity, but the total screen illumina- tion is maintained constant by the additional light coming through the adjacent film frame No. 2, which is transmitted to the screen by the in- coming pair of lens wheel elements. At the intsant when the radial line
between lens wheel elements crosses the principal axis, the line between frames No. 1 and No. 2 will also be on the principal axis, and each of the frames No. 1 and No. 2 is supplying equal light to the screen.
As the film continues to move down- ward, the first pair of lens wheel elements moves further and further out of the light beam until they finally clear it entirely, and, at this instant, No. 1 film frame ceases to supply light to the screen, and No. 2 film frame supplies all the light reaching the screen and continues to do so until another pair of lens wheel elements enters the light beam. Stated briefly, the dissolving action between film frames, which provides a smooth pro- gressive and relatively long transition, is accomplished entirely automatically by the passage of the lens wheel ele- ments through the light beam.
As far as the effect on the screen is concerned, this dissolving action is exactly identical to the effect obtained with a double stereopticon having a pair of iris diaphragms operated by a common control handle in a manner whereby one diaphragm closes pro- gressively at the same rate at which the other opens. That is to say, in
the revolving lens wheel system, each film frame, starting from zero, fades in smoothly to full intensity which continues for the greater part of the picture cycle and then fades out smoothly to zero. No other system of transition can equal this in smooth- ness and in the accuracy with which the dissolving images are superim- posed.
Film Shrinkage Problem
The next important function to be provided for in any continuous pro- jector is the adjustment of the optical system to compensate for variations in film shrinkage. Generally speak- ing, the amount of shrinkage in any given reel of film does not vary ap- preciably from one end to the other, hence it is seldom necessary to make readjustment during the showing of any single reel or even during a com- plete picture. However, it is neces- sary to adjust the optical system when a new subject having very little shrinkage is to be run on the program with an old one which has shrunk con- siderably, and this brings us to the second stiff problem the designer must solve. The exact and complete ex- planation of how this is accomplished in the revolving lens wheel system is rather long and involved and requires the use of several diagrams, but I will (Continued on page 33)
TRIPLEX LENS TURRET
A door is furnished with lens turret which encloses
the entire mechanism and allows ample room for
the projectionist
TRIPLEX Lens Turret
For Movietone — Vitaphone — Magnascope
Also suitable for all wide image from stand- ard film processes.
LEGEND:
1. Handle for revolving lenses into direct position of aperture.
2. Stop position, insuring lenses always coming into same position.
3. Block to be put in same position as present lens holder.
4. Support in turret to center frame of mechanism, in- suring durability and steadiness.
5. Lens fastening screw — in a position that is easy to get at.
6. Collar on lens to adjust picture in position of screen, side to side and top and bottom, without moving pedestal. Also for centering lens for Movietone.
Sold and Manufactured by
Capitol Motion Picture Supply Co.
630 Ninth Ave. (Write for Literature) New York City
32
Motion Picture Projectionist
November, 1930
YOU
WOULD NOT
revert to the obsolete hand- crank type of projector THEN
WHY
SHOULD YOU
maintain the nearly obsolete method of cueing and change-overs. The Cue-meter has revolutionized the art oP projection There is no guesswork • • • Cue-meters are infinitely accurate.
Ask your dealer or write for* further information
THEATRE ENGINEERING SERVICE COMPANY
'442 Beachwood Drive Hollywood, California
DON'T GU€SS---USE CUE -METERS
Normal Images From Sound -On -Film
— made possible by speed-method change from silent or sound-disc films. Here is the simplest and most satisfactory system yet devised to eliminate masking, faulty centering and black flipper, by providng —
ACCURATE FOCUS
PERFECT ALIGNMENT
CORRECT PROPORTION
ADJUSTABLE
LENS
MOUNT
Combines instant lens change, side shift for centering image, and accurate focusing adjustment in a compact, sturdy device quickly installed on a Simplex head.
Lenses may be changed, shifted and focused for either silent sound-on-disc or sound film in less time than it takes to tell about it.
Side shift is limited by an adjustable stop screw. A simple adjustment assures repeated automatic centering merely by shift- ing the lever conveniently located OUTSIDE THE PROJECTOR HEAD.
Easily installed by simply removing your present lens holder and slide and inserting the new Lens Holder designed to fit per- fectly. No necessity for cutting the front plate or changing doors. (Available also for Motiograph.)
__ PROPORTIONAL
^F^ APERTURE
GATE
Apertures for both sound-disc and sound-on-film are mounted in an E-16 Simplex Film Trap which instantly replaces that on your machine. Slight movement of the accessible lever shifts either aperture into exact framing position.
Apertures are machined to such precise limits that projected images will be perfectly true with respect to frame, size and pro- portion.
Two types of proportional aperture gates are available. One is for use with your present single set of lenses, whereby you will obtain an image slightly smaller with sound film than with, normal film. The other requires use of the Adjustable Lens Holder plus two sets of Lenses, and projects identical images, regardless of film.
List
$25.00
List
$35.00
CHICAGO CINEMA EQUIPMENT CO
1738-52 N. SPRINGFIELD AVE., CHICAGO, ILL.
WRITE FOR BULLETINS No. 41 and 42
November, 1930
Motion Picture Projectionist
33
try to describe the underlying prin- ciple as simply as possible.
Going back to our simple lens ex- periment again, you will recall that the apparent displacement of the horizontal line was proportional to the displacement or decentration of the lens, the maximum bending effect for a given lens being obtained when look- ing through the extreme top or bottom edge. It is also true that the bending effect is proportional to the refractive power or strength of the lens. Neither of these factors, however, offers any help in the solution of the present problems because the refractive power and maximum decentration are fixed once and for all by the physical di- mensions of the lens wheel elements. We must look elsewhere for adjust- ability in the revolving lens wheel system.
The only other factor which can produce a variation in the apparent displacement of our horizontal line, as viewed through a lens, is the dis- tance from the lens to the line under observation. In other words, a given lens, of fixed refractive power and diameter, will cause a fixed maximum angle of deviation, but the apparent displacement resulting from this fixed maximum angle of deviation is pro- portional to the distance between the lens and the object under observation. It is evident, therefore, that changing the distance from the aperture plate to the revolving lens wheels, in our projector, will vary the apparent dis- placement. This is just what is re- quired to accommodate variations in film shrinkage which have the effect of changing the distance between centers of film frames.
The greater the amount of film shrinkage the shorter will be the dis- tance between film frame centers and, therefore, the closer the aperture plate must be to the revolving lens wheels. But everyone knows that changing the distance from the aperture plate to the objective is the means whereby focusing is normally accomplished, and any change here, however slight, will interfere with the definition of the screen image, hence it is apparent that the operation of adjusting for variations in film shrinkage and focusing are very intimately related in the revolving lens wheel projector. As a matter of fact they are per- formed simultaneously, the change m the back focus being made possible, without loss of definition, by a pro- portional displacement of the front element of the objective along the principal optical axis. The law governing the relation of the aperture distance and front element distance from the revolving lens wheels, is known, and, with this as a tool, it is a simple matter to design a propor- tional movement having single unit control, which provides simultaneous adjustment for both film shrinkage variation and focus.
If the projector is not in correct ad- justment for a given film, the dissolv-
Every production
can have both
color-tints and sound
EASTMAN Sonochrome Tinted Positive Films give charming atmospheric tints that express the mood of every scene, or the prevailing lighting of the picture. Besides, these films reproduce sound with exceptional fidelity. Through their use every production can have both color- tints and sound, for Sonochrome costs no more than ordinary black - and - white positive.
EASTMAN KODAK COMPANY
ROCHESTER, NEW YORK J. E. Brulatour, Inc., Distributors
New York Chicago Hollywood
ing images will not be exactly super- imposed on the screen, and there re- sults what might very properly be termed an astigmatic loss of definition which is most pronounced on hori- zontal lines and not at all present on vertical lines in the picture. That is to say, horizontal lines will not be sharply defined and the definition of any given line in the picture will be better the nearer the line approaches to the vertical. We might say, there- fore, that the adjustment of the optical system for varying shrinkage of film, which is accomplished by operating a single conveniently lo- cated hand-wheel, is, in reality, the operation of securing definition on
horizontal lines equal to that on the vertical lines in the picture. When the optical system has once been ad- justed for any given film, the defini- tion on vertical lines does not change, and any loss of definition on hori- zontal lines, due to change in amount of film shrinkage, is quickly noted by the projectionist and easily corrected.
Continuous Projection? What About It?
The trend of human thought is strange indeed, and very often the joy of anticipation is greater than the pleasure of realization. About every- one connected with the motion picture industry, has, at some time, thought of the advantages of continuous pro-
34
Motion Picture Projectionist
November, 1930
ASHCRAFT
SUPER HIGH INTENSITY LAMP
THE ASHCRAFT
SUPER HIGH INTENSITY PROJECTION LAMP
Among some of the prominent users are the following:
Fox Studios, Warner Bros. Studios, Met- ropolitan Studios, Universal Studios, M-G-M Studios, United Artists Studios, First National Studios, Fox Theatres (New York and Los Angeles) and ^^====^^===^^^=^^^^====
Warner Bros. Theatres.
Designed for theatres where an enormous increase in light is necessary for the presentation of large pictures. It is a noteworthy fact that all motion picture studios now developing wide film are using The Ashcraft Super High Intensity Lamp.
Ashcraft Automatic Arc Company
4214 SANTA MONICA BOULEVARD HOLLYWOOD, CALIFORNIA
jection; some stress the value of pro- longed life of film; while others re- gard quietness of operation as of greatest value; all have hoped that some day continuous projection would be an accomplished fact. Now that a practical continuous projector has been developed, the question is, how is it to be introduced to the industry? The first step is naturally to make known its important characteristics and the following statements are made with that end in view.
Most of the advantages ordinarily credited to continuous projection are the direct result of continuous film movement, and although they are im- portant, especially in connection with sound film equipment, they are in reality minor considerations compared with the advantages of continuous projection as we have denned it, namely, the showing of motion in pictures through the medium of con- tinuous non-periodic screen illumina- tion. If all the benefits to accrue to the industry from the adoption of continuous projection resided in the advantages of continuous film move- ment, per se, it is doubtful if the cost of re-equipping theatres would be warranted. It is strange to me that the deep-thinking men of the motion picture industry have not begun to realize the value and possibilities of the dissolving transition provided by the revolving lens wheel system, for therein reside the prime advantages of continuous projection.
Just because our great-grandfath- ers got along with illumination from a few tallow dips, there is no reason why the present generation should do without electric lights. . . . So, after all, what about continuous projection? Does it represent progress? What are its real advantages to humanity?
That Certain "Quality"
In every direct comparison demon- stration (and there have been many of them made in the past seven or eight years, although in the early days, our presentations were unsteady and poorly illuminated and often suffered from lack of critical defini- tion), observers, both in favor of and opposed to the development, have never failed to notice, in spite of inherent defects, a "quality" of image unknown to intermittent projection. As the imperfections in optical and mechanical parts were slowly but steadily eliminated year after year, this "quality" became more apparent, and now, that our projection is pro- nounced equal to the best intermittent performance as regards steadiness, illumination and definition, this "quality" stands out as the striking difference between continuous and in- termittent projection. I shall not at- tempt to describe this "quality," but those who have seen a demonstration of the revolving lens wheel projector, know it is real, and those who reason will get some understanding of what this "quality" may be from the fol-
November. 1930
Motion Picture Projectionist
35
lowing analysis of conditions at the screen.
The Flicker Phenomenon
Some of the characteristics of periodic illumination are commonly known and the examples are numer- ous. Here is a typical one. The other day, late in the afternoon, while riding in a ear on the elevated rail- way structure in New York, I happened to be seated where the sun shone on my face. The sun was too bright to look at it directly, but it was not uncomfortable to look in its general direction until the train pulled into a station and the shadows of successive window frames, forming the station enclosure, blinked across my eyes, at first rapidly and then more slowly as the train came to rest. The sensation that momentarily came over me, due to the low frequency beat, was not unlike that caused by seasickness. A similar condition obtains when one walks alongside of a high picket fence when the sun is shining brightly from behind it in such a manner as to cast shadows across the eyes. These, of course, are low frequency phenomena and the effects are often very marked.
Stepping up a little in frequency, we come to the peculiarities of 25- cycle small unit incandescent lighting, and here we find some characteristics which appear in motion picture pro- jection, although the shutter fre- quency in sound picture presentations is 48 cycles. If one looks directly at a small incandescent lamp filament which is operating on 25-cycle cur- rent, or at a small area illuminated by such a lamp, there is scarcely any flicker noticeable at the filament or on the small area, but one knows, from the effect of light entering the eyes from areas surrounding the spot under critical observation, that the general illumination is not steady.
This phenomenon is due to the structural nature of the retina of the eye. The relatively small central area of the retina, while possessing the greatest resolving power, is far less sensitive to periodic illumination than are the outer zones, hence, when one looks intently at one small area, the flicker sensation seems to come from somewhere else, and, the further removed the sources of illumination from the center of observation, the more pronounced the flicker sensation. While walking through the stations of the Hudson Tubes, when 25-cycle station lighting was used, I have often observed a very decided strobo- scope effect on the posters in the passageways. On looking directly at any word or small picture area, it would appear clear-cut and station- ary, while similar surrounding ob- jects, although less distinctly visible due to being imaged on the outer zones of the retina, showed the characteristic stroboscopic multiple outlines. This effect is undoubtedly
20/40 to 100/200 Ampere 2-Bearing Actodector
EXCEPTIONAL COMMUTATION
As a result of exceptional commutation Roth Actodectors are especially suitable for use with sound equipment. This feature, combined with the ability of Roth Acto- dectors to maintain projection arcs of uni' form intensity and unvarying brilliance — - even during change-over — is responsible for their wide use by the large circuits. . . . Furnished in 2- and 4 'bearing types — vari- ous si?es from 20 to 600 ampere capacity — standard voltages of 75, 85 and 100 volts.
ROTH BROTHERS AND COMPANY
Division of Century Electric Com pany
1400 W. Adams St. » » » Chicago, III.
//
THEY KEEP A-RUNNING
//
another manifestation of the flicker phenomenon.
Much has been written about motion pictures and their effects on the eyes, but nothing has come of it thus far because there was no practical way of overcoming the "intermittency," as many writers describe it. The aver- age movie patron pays for seeing the show in two ways: first, in cash for the privilege of looking at the screen, and second, in more or less discomfort which results from eye strain and nerve fatigue, and some pay dearly in this latter respect.
But everything worthwhile costs something, and the human mechanism is wonderfully adaptable to its sur- roundings, so our average movie-goer, having never experienced any better motion picture presentation, is satis- fied. Moreover, has he not been
assured time and again, that the movies do not tire his eyes any more than reading does? But if this is really true, why do professional film folks invariably sit well back of the center of projection rooms whenever they view pictures? Surely .the best place in the whole room to see the defects and other details, is up close to the screen and not back near the projection booth. Of course, the further the position of the observer from the screen, the smaller will be the angle the screen subtends at his eyes, hence the areas of the retina most sensitive to flicker effects will be less likely to be illuminated by the screen. Perhaps the experienced screen observers have chosen the rear seats without really knowing why, but they have certainly chosen wisely, be- cause the flicker and stroboscopic ef-
36
Motion Picture Projectionist
November, 1930
SietierScreenSiemlts
with
BRENKERT
LOW INTENSITY REFLECTOR LAMPS
OROVEN by installations throughout United States A and Canada, you are assured of complete satis- faction when you specify Brenkert Lamps.
Made and guaranteed by one of the oldest and larg- est manufacturers of light projection equipment for the theatre and sold and serviced by progressive in- dependent supply dealers throughout the country.
Write for literature or see your independent dealer.
Brenkert Light Projection Co.
ENGINEERS and MANUFACTURERS St. Aubin at East Grand Blvd. Detroit, Mich.
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fects are unquestionably more pro- nounced closer to the screen. If you don't believe it, just try the experi- ment of sitting in the front row through an entire presentation, and don't forget that, in most houses, you are still several times the screen height away from the nickering images.
Incidentally, it is interesting to speculate as to just what effects wide screen presentations will produce in connection with this phenomenon. We have already heard much about the difficulty of getting good light dis- tribution on wide film projection. Perhaps it may not be altogether the "distribution" after all. There is one other thing to be observed in connec- tion with the consideration of flicker effects, namely, the greater the in- tensity of illumination per unit area of screen surface, the more pro- nounced will be the flicker at a given frequency. While flicker is seldom visible in the darker areas of a scene, it invariably appears as a scintillation or glistening effect in the highlights if the screen is brightly illuminated.
Excessive Screen Illumination
The demand for more and still more intense screen illumination is re- sponsible for another effect which is not altogether advantageous. In the first place, the clear whites become glary and therefore hard to look at, especially when they cover most of the screen area, as in snow, water and sky scenes. In the second place, the scale of gradations, from clear whites to darkest shadows, is unbalanced by a preponderance of detail in the brighter parts of the picture and a dearth of detail in the darker por- tions. It is not difficult to account for this effect. The iris of the eye ad- justs itself to limit the intensity of the light reaching the retina, so, if the highlights of the picture under observation are excessively bright, the iris opening is correspondingly re- duced in size to cut down the average intensity of the retinal image, thus blotting out gradations in the darker areas of the picture by admitting too small an amount of light from these areas to cause them to become dis- tinguishable one from the other. While this effect is present with con- tinuous non-periodic illumination, there is considerable scientific data, concerning the "speed of seeing," which indicates that it is greatly accentuated by intermittent illumina- tion, even at the relatively high fre- quency of 48 cycles. The general effect of excessive screen illumination is in some ways similar to the effect of glare spots, the evils of which are now quite generally recognized.
Much more can be said about inter- mittent screen illumination and further investigation will undoubtedly disclose other reasons why it causes eye strain and fatigue. There is no denying that the sound picture pro- jection rate produces a more pleasing show than the old 16-picture-per-
November, 1930
Motion Picture Projectionist
37
second rate did, but the illumination is still intermittent and the eye strain effect has not been noticeably re- duced. A 16-picture rate with present screen intensities gives a decidedly flickery performance. However, for conclusive proof that intermittent pro- jection does cause eye strain, one has but to turn to the great quantities of statistical data already compiled, study the reports of physicians and other authorities, and analyze their recommendations concerning the use of motion pictures for instruction purposes in schools. In view of all this evidence, no intelligent person can deny the fact that intermittent projection causes eye strain.
While relatively few have ever seen motion pictures presented through the medium of continuous non-periodic screen illumination, everybody under- stands and appreciates the qualities and characteristics of images pro- jected with lantern slides. Did you ever hear of anyone sitting way back at a stereopticon show because the pictures hurt his eyes? Have you ever noted the pleasing qualities of lantern slide images projected as in- troductions to features? There is un- questionably a difference in "quality" which is quite apparent when the intermittent images come on over the slide images.
Continuous projection, by the re- volving lens wheel system, provides the kind of screen illumination pre- sent in lantern slide exhibitions and consequently produces slide "quality" in the presentation of motion pic- tures. Thus continuous projection, possessing many advantages over the intermittent system, surely represents improvement and progress in the art of motion picture presentation. By providing a more pleasing show, it adds to the theatre patron's enjoy- ment, and by greatly reducing eye strain and nerve fatigue, it removes one of the most serious factors tend- ing to reduce attendance at motion picture theatres.
The question is this ; Which is pref- erable, a shutter cut-off transition and intermittent screen illumination with all of its well-known shortcom- ings, or a smooth dissolving transition without shutter effect and lantern slide "quality" of screen illumina- tion? Equipment manufacturers are puzzled. What will be the reaction of Producers, Exhibitors and the Public to this question?
Big Technicolor Net
Technicolor and subsidiaries for the eight months ended Aug. 31, report net profit of $942,590 after opera- tions, amortization and taxes. Gross profit was $1,849,019. Current assets totaled $1,397,396, of which cash com- prised $289,387 and accounts receiv- able $570,880. Current liabilities aggregated $589,364, accounts pay- able totaling $320,861 and surplus $1,891,217. Total resources of the company are $7,790,071.
The American Public Has Spent More Money this Year for Amuse- ment Than Ever Before
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Schenck on Color, Wide Film
Warning against a repetition of the industry's experience with color, Joseph M. Schenck said that this ele- ment in picture-making has lost pop- ularity not through its constant use, but through abuse. Producers, in a hurry to get color product on the market, put out prints inadequately made, he asserted. The results were the same as if they had produced bad pictures as theatergoers formed a dis- taste for them.
Color must be used discriminately, said Schenck. Costumes and back- grounds must be selected with great care, as in the case of "Whoopee," he declared. He believes that the in-
dustry needs a three color process in order to produce the best results.
Television 5 Years Away Television, if it ever arrives on a commercial level, is at least five years away, said Schenck. He stated he has personally examined two processes in which interests were offered him.
In addition to "The Bat Whispers" wide film will be used in some se- cuences in Douglas Fairbank' "Reach- ing for the Moon," the United Artists chieftain said. The company's wide film process involves making the scenes on 65 millimeter film, and re- ducing it to 35 millimeter in printing. A projector attachment permits en- larging of the image when screened.
38
Motion Picture Projectionist
November, 1930
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45 West 45th Street, New York City
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Enclosed please find $2.00 for which enter my subscription for one
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Inventive Trend Shown in Annual Patent Report
Inventors throughout the country stimulated by the wave of prosperity which was still showing great vigor in the first part of the last fiscal year, established a record for all time in their dealings with the Patent Cffice during the twelve months which ended June 30. While the industrial decline was clearly apparent during the greater part of that period, Patent Office figures made public showed that the creative effort previously encour- aged on such a large scale had con- tinued in numerous cases to fruition. Many of the patents represented de- velopments in the mechanical and chemical fields, which have come to be the fairways of modern life.
During the last fiscal year, his pre- liminary statement showed, the appli- cations for mechanical patents totaled 91,430 as compared with 87,039 in the preceding year. The 49,599 patents issued exceeded the total of the pre- ceding fiscal year by 5,982.
The "10-Cent Store"
The Patent Office "10 cent store" also did a phenomenal business, since the number of printed copies disposed of during the year increased from 6,- 405,000 to 7,453,000, or 17 per cent. In fact, the number of printed copies disposed of increased from 5,595,000 two years ago is 7,153,000 last year. This means that each day the Patent Office disposed of 5,000 copies more than it did two years ago.
The number of photostats made by the Patent Office increased during the year from 713,000 to 978,000, or 37 per cent, bringing a profit of over $40,000.
The total receipts for the year were over $4,000,000 or $300,000 greater than the previous "peak" year, 1929.
Weston Test Set
The Weston model 547 test set manufactured by the Weston Elec- trical Instrument Corp., Newark, N. J., is designed to meet service require- ments as found in the projection room and studio.
It will measure the various AC and DC voltages used for the audio am- plifiers either at the socket or at any part of the set while in operation.
Has Many Adaptations
It will test continuity of circuits and test tubes including the AC or DC screen grid (type '24 and '22), also the '50, '45, and '10 type power tubes under the same conditions as exist when in their sockets. All these tests, it is said, can be made by using the regular voltages normally supplied to the set by its batteries or rectifier power units, with no change in con- nections, so that no auxiliary power supply is required.
The AC voltmeter is provided with ranges up to 750 volts, which may be used to measure the voltage of the plate supply transformer.
November, 1930
Motion Picture Projectionist
39
Film Mutilation
(Continued from page 29)
more of these points, it must be admit- ted that the direct cause of a great amount of film damage is never defi- nitely settled between the film ex- changes and the projectionists, espe- cially when the projectors in question have been gone over quite carefully and everything has been found to be in apparently good condition.
In cases of this kind, it is only natural to assume that the film stock is at fault. There are, however, vari- ous projector parts, generally consid- ered more or less unimportant which, as a rule, receive little or no attention on the part of the projectionists. The result is that the film trouble is apt to start at any one of them.
The following resume covers the more important points which must be given careful attention by the projec- tionist, if the maximum wearing qual- ities are to be obtained from the film.
Tension on Springs in Gate or Trap
One of the principal sources of trouble is the use of excessive ten- sion exerted on the film by the springs in the gate or trap. A great variation will be found in tension on various projection machines being used in the trade. Moreover, there are some projectionists who are not
familiar with the amount of tension which should be used, and as far as we know, there is no set standard which is generally accepted as being correct.
It is common practice to set the springs just tight enough to hold the film stationary at the speed which is used in a given theatre. Excessive tension as high as 34 ounces has been
XL
f- — ^"
T
Fig. 2A. A spring balance gradu- ated in ounces is convenient for tension tests.
Fig. 2B. Tension tests are made on each side. 1 is the film, 2 the pressure plate and 3 is the spring balance at S ounces.
found to exist on certain projection machines and causes badly nicked and pulled out perforations. Heavy ten- sions on one side can be caused by a poorly adjusted, weak or broken spring and results in an uneven pull- down strain on the film. On projectors using the gate a stop or catch is pro- vided which holds the gate in the same position each time it is closed.
Projectors using a trap door or pressure plate are not provided with a stop of any kind, thereby allowing varying amounts of tension to be ap- plied to the film. The trap door or plate should never be let back against the film with great force as this re- sults in exceptionally heavy tension, which must be withstood by the film until the door or plate has worked back to its proper position. The proper tension exerted by the springs should be 8 ounces for each spring or 16 ounces combined tension. Below Figure 2 is given the proper method of making a tension test.
Referring to illustration JB : first the tension on one side and then on the other is taken by using one-half of a strip or film about 8" long. This strip is prepared by slitting a piece of film down through the center. Care should be taken to observe that the perforations on this strip of film are free of the teeth on the intermittent sprocket and are held properly in place by the tension shoe before pro- (Continued on page 44)
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40
Motion Picture Projectionist
November, 1930
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Practical Hints on Storage Batteries
By S. C. Aikenhead* Willard Storage Battery Company
STORAGE batteries reduce to a minimum noise due to variations in the current through the filaments of the exciting lamp and the tubes in the first four stages of amplifica- tion. The proper design, manufacture and performance of the batteries is therefore very important to good quality sound reproduction.
Batteries must be in good condition, freshly charged, and of ample ca- pacity; batteries cannot be used to anywhere near the point of complete discharge on account of the voltage drop that occurs, which drop renders it impossible to obtain the proper current values.
Failure of batteries during a pro- gram may be guarded against by the periodic use of a suitable low reading voltmeter, carefully observing the voltage of each battery when the ap- paratus is drawing its normal oper- ating current. Where the voltage of a fully charged battery shows indica- tion of abnormal and rapid drop, when put on load, to a point below 5.8 volts, an internal inspection should be made. Voltage measurements made on a battery when it is NOT delivering full operating current do not give a reliable indication as to its fitness for further use.
Causes of Noisy Operation
Several conditions may exist in a storage battery causing noisy opera- tion of the system. Careful attention
* Notes from a lecture delivered by Mr. Aiken- head before the Cleveland Chapter, A. P. S.
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must be paid to the following points:
(1) A battery continues to evolve bubbles of gas for sometime after it is taken off charge, and while it is doing this it will cause noisy opera- tion.
(2) Corroded and dirty terminals make it hard to secure good electrical connections. Clean the terminals and scrape the contact surfaces bright with a knife or wire brush, coat the contact surfaces with pure vaseline or non-oxide grease, tighten the clamping nuts and wipe off any sur- plus grease.
(3) Battery tops on which acid has been spilled, or dust or dirt has collected, are a likely source of noise. Take particular care to clean under the connecting bars, as ALL parts of the insulating surface on the top of the battery must be clean.
Sulphuric acid is very corrosive in its action and will ruin clothing or other fabric. It should be neutralized immediately when spilled with house- hold ammonia, a bottle of which should be available at all times. Use pure distilled or other approved water only for filling batteries and this water must not be stored in metallic containers. Ordinary water or water stored in metallic containers contains impurities harmful to batteries.
Never add acid under any circum- stances. The acid in a battery is not "used up" by the chemical reaction and never needs replenishment un- less it is upset and spilled in which case very careful attention is required by a competent battery man.
Careful Checking Necessary
The most reliable means of check- ing the condition of charge of a storage battery in daily practice is that of measuring the specific gravity of the electrolyte. The specific gravity of pure sulphuric acid is about 1.835. Enough water is added to this to bring the specific gravity down to that required for the particular service on which the battery is to be used — in sound work about 1.285 or 1.300. When fully charged all the acid has been forced out of the plates into the electrolyte and the gravity should read on the hydrometer 1.285 or 1.300 or whatever is normal for that par- ticular battery.
Two different types of storage bat-
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November, 1930
Motion Picture Projectionist
41
teries are in general use on sound equipments, the low gravity type and the high gravity type. The charg- ing of the low gravity type is taken care of by the operator. The high gravity type is floated across a gen- erator to remove ripples from the gen- erator voltage and requires special care.
It is not necessary to take specific gravity or voltage readings of all cells in your battery equipment each day. Read one cell in each bank daily as an indication of the state of charge of the entire battery. Once every three months select a new pilot cell. When selecting a new pilot cell charge the battery until the cell shows no further increase in specific gravity or voltage for a period of one hour and use this value as the "Fully charged" indications for all future readings taken on that cell. Test all cells every 60 or 90 days.
Points to Remember
Periodically give the batteries an equalizing charge by continuing the charge at a lower rate until the cells gas freely and until the readings show no further increase over a period of one hour.
The following rules should be borne in mind:
(1) Always charge at the lowest rate possible consistent with the time available for charging.
(2) The charging rate can be com- paratively high when the bat- tery is in a discharged condition.
(3) The charging rate should be low when the battery is almost fully charged.
(4) Never allow storage batteries to get hot. The nearer the battery is to being fully charged the more heat is generated by a given charging current.
22 Television Stations Now Operating in U. S.
THE Federal Radio Commission reports that 22 Television sta- tions are now being operated in the United States by 18 companies.
In licensing applicants for fre- quency assignments for television transmission the Commission insists that they must produce evidence that their work is legitimate re- search. The main purpose of the regulation is to encourage and fos- ter technical progress in television in order that the public may be bet- ter served. Because of the scarcity of available channels, the Commis- sion has been forced to deny a large number of requests for television sta- tions from applicants who were not interested in television from an ex- perimental standpoint but merely from its commercial aspects.
Many Problems Unsolved
Efforts are being made to hasten the arrival of television, but tech-
nical as well as economic obstacles still must be surmounted, according to Dr. C. B. Jolliffe, chief engineer of the Federal Radio Commission, who states that within the laboratory and on the five experimental visual broadcasting channels now being used, technicians are doubling their efforts to speed the day when tele- vision will be practical.
On the television channels set aside for experiments, Dr. Jolliffe pointed out, there are twenty-four licensed stations as well as seven under con- struction. These transmit images which may be picked up by visual broadcast receiving sets, he said, ex- plaining, however, that at present television has little sustained enter- tainment value.
Urge Standards Adoption Dr. Jolliffe urged the adoption of standard scanning systems by ex- perimental television stations, as a means of expediting development. "The Commission, while it does not require the use of standards in tele- vision, feels that the adoption of a standard scanning system by as many as possible of the companies engaged in the experimentation will increase the value of the experiments," he asserted.
Standards might be adopted such as those of the Radio Manufacturers Association, which provide for scan- ning from left to right and from top to bottom, with pictures of 48 lines, and with 15 pictures per sec- ond, he pointed out.
One of the major television prob- lems, declared Dr. Jolliffe, is that of maintaining synchronous operation between sending and receiving ap- paratus. Unless the receiving ap- paratus is calibrated at precisely the same speed as that of the emitted impulses, the pictures re- ceived are off-tangent, he said.
Cleanograph
Automatic Sound Track Cleaner
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Technicolor cameras are now being equipped with a newly developed lens which widens the field of sharp focus and brings into backgrounds definition heretofore impossible in color pictures, it is announced by Dr. Herbert T. Kalmus, president of Technicolor. The improved color work in recent Techni- color pictures is the result of this new lens, which is the outcome of 16 years of experiment, says Dr. Kalmus.
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42
Motion Picture Projectionist
November, 1930
Good Projection
Requires
Good Rectification
Statistics on Theatre Fires
M. P. 25-25
Good Rectification Means
Forest Rectifiers
THIS Forest Rectifier meets the de- mand for a single unit to supply direct current for two projectors, and will funish 15 to 25 amperes to either projector continuously.
It supplies a steady direct current, free from pulsations, and will produce a better light than other current supply devices. The only wearing parts are the bulbs which will last at least one thousand hours and usually much longer since only two bulbs are being used at a time (ex- cept during change over) and the load is alternately carried first by one set of two tubes then the other two as the projectors are alternately used.
This Forest Rectifier embodies the use of four rectifier tubes which are connected to supply current to two direct current circuits independent of each other thus preventing loss of current at the first arc when the second arc is struck.
Both arcs can be operated at the same lime during the change over period and there will be no diminishing of the light from one projector while lighting up the second.
Two Ammeters are mounted on the unit which will show at a glance the amperage being used at either arc.
Links are provided for operating from 110-220 or 240 volts.
Rectifiers for all purposes made in 15 amp., 25-25 amps., 30, and 65 amps, sizes.
We are specialists in our field. Send us your technical problems. Literature on request.
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THE observation of Fire Preven- tion Week during the early part of October of this year brought to light some interesting, and, in some cases, astounding facts relative to theatre fires.
In the records of the National Fire Protection Association there are listed 530 such fires, caused from a wide variety of causes. As was brought out in the discussion of the National Electric Code by Jac R. Manheimer in the October issue of Motion Pic- ture Projectionist, the fire hazard in theatres has been increased with the installation of talking equipment and it is therefore imperative that a new code be devised and extra pre- cautions taken by each individual theatre manager to keep careful watch, reducing the hazard as much as is within his power.
In the opinion of experts, 75 per cent of the recent theatre fires were preventable had proper precautions been taken in advance.
The Projectionist's Role
It is but natural that the larger percentage of theatre fires start in the projection room and it is a re- markable tribute to the efficiency and cool-headedness to the Projec- tionists that the vast majority of such fires are confined to where they started. Projectionists on numberless occasions have proved themselves real heroes and the same may be said of ushers and other theatre employees who in many instances have pre- vented loss of life and damage to property by quick, cool, decisive action when theatre fires have broken out.
It is good that such things have happened. The example of such ac- tion on the part of these men might
well be an example for others and undoubtedly will be the means of in- stilling the same courage into others.
It rests with the manager of the theatre to see to it that his staff is properly