International photographer (Feb-Dec 1929)

Sixteen The INTERNATIONAL PHOTOGRAPHER May, 1929 Dupont Sound Film Smith & Aller, western distributors of Dupont raw stock, have transmitted to The International Photographer the accompanying bulletins on the new V.D. and V.A. Sound Recording Film issued by the Dupont-Pathe Laboratories: VD — "Variable Density Sound Recording Film" V.D. TYPE The most important features of the V. D. film are its high resolving power and low gamma infinity. A special treatment is given the film in the course of its manufacture which considerably increases its resolving power and makes it capable of recording requencies far higher than those needed in practical work. The same treatment also serves to limit the maximum gamma obtainable with the film to a value of approximtaely 0.8 as compared with a value fo 2.8 which is representative of positive emulsions. This unique feature insures far greater ease and exactness in the control of development since the increase of contrast with time of development is much slower than with positive film. It has long been recognized that it is very advantageous to develop a film to at least 7 5 per cent of its gamma infinity. This criterion is met satisfactorily by the V. D. film with its gamma infinity of 0.8 since it is common practice to develop variable density sound track to a gamma of 0.5 to 0.6. Another distinct advantage which is characteristic of this film, is its freedom from the halo effect at the junction of a high and low density. The bromide liberated restrains development in the adjacent portion of the low density. This effect is characteristic of emulsions of high gamma infinity and becomes objectionable in the recording of high frequencies of large amplitude. V. D. film does not require any greater exposure than positive stocks and will improve the reproduction of sound, not only because of its high resolving power and freedom from halo effect, but also because of Its fool-proof development characteristics. VA — "Variable Area Sound Recording Film" V. A. TYPE A survey of the filed which was made prior to the working out of a special film for variable area recording revealed the fact that positive films do not have sufficient sensitivity for the purpose. Recording engineers are forced to operate their exposing lamps considerably above the rated amperage— a practice which shortens the life of the lamp and increases the clanger of lamps burning out during the taking of important scenes. In addition to this evil, laboratories find it necessary to force development of the sound track in powerful developing solutions. This practice slows down laboratory production and produces undesirable effects in the film. The new DuPont V. A. film with its higher sensitivity not only allows the reduction of recording lamp currents to safer levels but also shortens very considerably the time of development necessary to produce the desired track density. Some idea of the improvement in working conditions with DuPont V. A. may be obtained from the results of a comparative test made by the technicians of a concern using the variable area recording system It was found that positive stock exposed at 4.2 amperes required a development of by2 minutes as compared to a developing time of 4V2 minutes for DuPont V A ex I i°^e<ii at, 3iS ,amPeres The comparison test also included the recording of very high frequencies and it was found that the DuPont V. A. was fully equal, if not superior freq'uSs810^ '" "" *WUt3r l° r6C°rd h*h it1^ sl?°rt the use of DuPont V. A. makes it possible for sound recording engineers to reduce their lamp currents and increase their factor of safety; it makes possible a very considerable increase in production for the laboratories, and oes away with the bad film effects attendant on forced development. In including all these advantages in the DuPont V. A. it has not been necessary to sacrifice, in the slightest degree, the ability of the film to record frequencies far higher than those needed for practical purposes Spring Meeting S. M. P. E. The spring meeting of the Society of Motion Picture Engineers to be held in New York, May 6 to 9, presents an exceptional opportunity for the Motion Picture Industry to become acquainted with the work of the Society. Heretofore the meetings have been held in Boston, Washington, Norflok, Virginia, Lake Placid, Hollywood, Rochester, and other places which offered certain attractions or special facilities, but were difficult for some of our members to reach and therefore limited attendance. The meetings of the Society of Motion Picture Engineers have been uniformly successful, but the one to be held this year in New York should be the largest in the history of the organization. The Society of Motion Picture Engineers, since its formation in 1916, has quietly performed a service of inestimable value to the Motion Picture Industry. The work of the Society has been carried on with comparatively litlte recognition and practically no help except from its own members and the firms represented by membership. In spite of this the Society has prospered and built up a splendid record of accomplishment. The editor of "The Nation's Business" recently attributed much of our national prosperity to the work of industrial organizations working along lines similar to that of the S. M. P. E. The transactions of the 'Society constitute a history of the technical davance of the Motion Picture Industry. Through the Society of Motion Picture Knginners knowledge has been increased, interest created and pride developed which have been a tremendous force for the advancement of the industry in its technical departments. It is expected, and is certainly to be hoped, that the Motion Picture Industry will avail itself of the opportunity to see the Society actively function during the coming spring meeting in New York this year. The technical organizations and departments of this industry are to a large extent located in other places, but New York is the headquarters of the executives of this industry. Every effort should, therefore, be made by our members to see that the leaders in this field attend one or more sessions of the convention. The Convention Committee has worked very hard to make the meeting a success and the Papers Committee has prepared a program of exceptional interest. It is important, however, that members of the Society do their share toward making the meeting a success. A large attendance has a stimulating influence and our members should reward the committees for their work by being present at business sessions and social events. Members living in New York are under the particular obligation to do this. They should put aside thought of their offices, consider themselves out of town and devote as many days as possible to getting all they can out of the spring meeitng of the Society. In this way they will greatly help the work of the Society, derive a positive practical benefit and enjoy the recreational program which is laways an important feature of meetings of the Society of Motion Picture Engineers. Chairman P. A. McGuire, F. C. Badgley, Jos. Dubray, G. C. Edwards, Irl Gordon, O. A. Ross, P. H. Griffith, J. R. Theiss, Publicty Committee. A Color Pioneer Alfred Gosden, one of the distinguished pioneers of the motion camera specializing in color work, has joined the forces of Multicolor as laboratory technician. Brother Godsen began hi scareer in color photography with Kinemacolor, in the service of which organization he photographed such great spectacles as Durbar in India, and the coronation of Edward VII of Great Britain. Brother Gosden's present assignment is at Real-Art studios. Norton "Doc" Travis adds this gem to the "Pioneer" series. It was shot in 1906 at the old Twin-plex studio in New York City, owned by a man named Ruby. The shot discloses "Doc" with his Warwick camera, an English model, considered good in those days. The picture under execution was "The Dock Rats of New York," directed by Red Mack. "Doc" says that the first real motion picture camera was the Black, also an English make. o Poetry At the last open meeting President Wyckoff received the following telegram from the I. A. boys on location away up on the Feather river with Director Edwin Carewe "Evangeline" company: Hollywood Chamber of Commerce, Sunset at Hudson, Hollywood, Calif. "Can't be at the meeting so we send this little greeting; we are on the Feather river where we all stand and shiver. It rains, snows and freezes and we miss those southern breezes." Bob Kurrle, Elmer Dyer, Al Greene, Joe Novak, Bob LaPrell, Rod Tolmie, Jim Palmer. THE EVANGELINE GANG. Jackson Rose has recovered from an attack of influenza. Jack was too rugged for the "flu" to do much damage and henceforth no doubt it will be glad to leave him alone. * * Daniel B. Clark has trained down into the light heavy-weight class since he returned from Tahiti. Dan ascribes this falling off in avoirdupois to lack of the Tahiti diet of cocoanut juice. Brother J. M. F. Haase, chief aerial photographer of the U. S. Battleship Fleet, North Island, San Diego, is shifting his field of activity to Alaska. Hope you locate some gold mines up there J. M. Brother R. B. Hooper has entered a new exploitation field by signing a fiveyear contract as publicity man with Lillian Lane, well known stage and radio entertainer. Brother Hooper became interested in Miss Lane because of her unusual southern voice which sound experts pronounce perfect for talking pictures. Miss Lane has been cast for an important part in Paramount's all-talking picture "Magnolia," featuring Buddy Rogers.