The Cine Technician (1938-1939)

September-October, 1939 THE CINE-TECHNICIAN 103 REPORT OF THE PROGRESS COMMITTEE FOR 1938 [Society of Motion Picture Engineers). This report covers the period June, 1938 to April, 1939. The most notable advance is in the new type panchromatic films, particularly the fine-grain Background Negative which permits considerable improvement in process scenes, and is also suitable for all types of exterior photography. The new camera designed and built by the 20th Century Fox Studios is outstanding and eagerly awaited. .Mitchell have also improved their N.C. Model. Due to extensive research, advances in the design of exposure meters are expected. Mole-Bichardson have a new series of baby spots, also a silent Arc Broad lor colour work. Several two-colour systems report expanded business, and Cinecolor have a new plant. Technicolor have now a much greater speed set of negatives, showing an increase of from two to four times on their standard negative. Dunning also announce a three-colour bi-pack process. A new non-slip printer developed on principles recognised by R.C.A. in 1936 has been perfected by Bell & Howell. It incorporates many novel features and operates in a horizontal position. The triple-head background projector is described in another section of these abstracts. Developments in sound recording effected by pushpull modulators, improved noise reduction methods, preand post-equalisation, track squeezing, volume compressors and limiters have made considerable improvements in quality and overall volume range. The use of squeeze track in release prints has grown during the period. L.U.O. E. R.P.I. SOUND INVESTIGATOR {American Cinernatographer). Electrical Research Products Inc., have recently produced an instrument, the Vocoder, that analyses speech and then proceeds to remake it in practically any form desired. The Vocoder was developed primarily for telephonic use and also plays an important part in the Voder instrument which manufactures artificial speech. The usefulness of the Vocoder lies in its ability to vary, singly and together, each of the elements of speech. Thus, for instance, it is possible to make one voice into a trio. Alt bough its potential use in the serious side of entertainment is great, the effects that could be achieved with it in the more bizarre productions like " Snow White " are almost bevond imagination. T.S. L-H. A NEW PHOTO-ELECTRIC METER (American ( 'inematographerj . The new Model 715, the Weston Master, is claimed to have extensive sensitivity for measurements in low li^ht ; increased range, permitting measurements from 1/lOth candle per square foot to 1000 candles per square foot ; automatic change from " Hi<di Light " to " Low Light " scales; a more selective and sharply directional viewing angle ; and an increased number of exposure values. The "Low Light" scale has wide divisions and bold numbers which make for easy, accurate reading, and the "High Light" scale has a viewing angle of only 30° which cutH out most of the unwanted extraneous light. T.S. L-H. SILENT WIND-MACHINE.— F. G. Albin (S.M.P.E Journaf). The machines generally used on motion picture production sets to create wind for pictorial effects are large motor driven propeller fans mounted on floor stands. The noise-level at high velocities is so high that satisfactory sound recording of the scene is practically impossible. Their size and shape require that the machines be placed at such distance that the directivity is not readily controllable. The additional hazard to sound recording of causing wind around the microphone always exists, and commonly the desirable microphone placement is sacrifixed in order to avoid this. A new wind-machine that has been adopted and tested for use for several years gives great improvement. It is a centrifugal blower, such as is commonly used in ventilating systems. Air is conducted by canvas ducts to the set. These ducts are equipped with variously shaped fittings and nozzles so that the air stream may be directed as desired. It has been found expedient to locate the blower outside the stage building and enter the duct through a special portal. Thereby the greatest noise source, the blower, is mostly insulated frtm the scene by the walls of the stage building. (It incidentally serves as a ventilator). Measurements of noise-level for various wind velocities indicate improvements up to 70 decibels in noise reduction. Thus sound recordings of scenes requiring wind are made possible where heretofore it was necessary to photograph the scene without sound and provide synchronized sound subsequently. L.U.O. ANALYSIS AND MEASUREMENT OF DISTORTION IN VARIABLE DENSITY R ECOR D I NG.— J. G. Frayne and R. R. Scoville (S.M.P.E. Journal). Several types of non-linear distortion in variable density recording are discussed and methods of measurement outlined. The two-frequency inter-modulation method is described. Mathematical and experimental relationships between per cent modulation and per cent harmonic distortion are established. The intermodulation method is applied to film processing for the determination of optima] negative and positive densities and overall gamma. Variance of these parameters from those indicated by classical sensitometry are traced to halation in the emulsion and to processing irregularities. The use of special anti-halation emulsions appears to reduce residual distortion effects and tends to bridge the gap between intermodulation and sensitometric control values. L.U.O. TECHNICAL VOLUNTEER WANTED THE Technical Committee of A.C.T. would be glad to hear from any technician w ith a knowledge of foreign languages who is willing to give a little time to the preparation of Technical Abstracts from foreign technical journals. The languages required are German. French, Russian, Czech, and Hungarian. Volunteers should communicate with Mr. T. S. Lvudon-Haynes, c/o A.C.T. . 9, Bromefield, Stanmore, Middlesex.