Journal of the Society of Motion Picture and Television Engineers (1950-1954)

recording and reproduction into very wide use in all communication fields, other than motion-picture release, by virtue of numerous basic superiorities. CinemaScope presented an opportunity to introduce magnetic soundtracks advantageously into the theater field; accordingly, magnetic materials are striped upon the picture print, after processing, to create the composite sound and picture release print. Although of lesser width than the conventional optical release tracks, superior signal-to-noise ratio is obtained and the reproduced frequency characteristics can be extended to 8 kc without significant loss. The three principal tracks are of 0.063-in. width; the fourth track is of 0.029-in. nominal width.27 Magnetic coating machinery has been developed by Reeves Soundcraft, Bell & Howell, Eastman Kodak, and Pyral of France. Minnesota Mining is presently developing a means to laminate solid magnetic tape materials onto 35mm film. The use of multiple magnetic tracks demanded a new reproducer design.25"27 It has been found universally convenient and advantageous to design and manufacture a wholly new unit to be mounted on the projector between the projector mechanism and the upper magazine. The problem of conversion parts for the many types of soundheads is thereby obviated and the performance, and use, of optical or magnetic scanning systems is not compromised in any way. All of the new reproducer attachments are film driven, have good flutter performance, satisfactory freedom from sprockethole modulation and are designed for adaptation to a large variety of projectors. One was used both as a recorder and reproducer to make and project the first composite film demonstration in CinemaScope in August 1953. Approximately 1200 theaters were fully equipped by year's end. Manufacturers in this country in full-scale production of theater equipments are: International Projector Corp., RCA Victor Div., Westrex Corp., Altec Lansing Corp., Ampex Electric Corp., Magnasync Manufacturing Co., the Ballantyne Co., Motiograph Co. and Century Projector Co. In the foreign field, sound equipment was manufactured by G.B.-Kalee Ltd., RCA Photophone, Ltd., Sound Equipment, Ltd., Western Electric Co., Ltd., in England; Brockliss-Simplex, S.A., Westrex Corp., Etablissements Charlin, S.A., Compagnie Radio-Cinema, in France; Zeiss-Ikon A.G., SiemensHalske Aktiengesellschaft, in Germany; Cinemeccanica S.P.A., Compagnia Generale di Costruzioni Cinematografiche e Radioelettroniche, Ing. Angelo Fedi S.A., Microtecnicca S.P.A., Officine Pio Pion, Officine Prevost, in Italy; Aga, in Sweden; Produit Perfectone S.A., in Switzerland; and N. V. Philips, in The Netherlands. The large picture used with CinemaScope would suffer from lack of sufficient brightness unless the available projector light could be made more effective. Consequently, as a part of the CinemaScope "package," Twentieth Century-Fox engineered, developed and put into production a lenticular screen material available in two basic pat-1 terns. The screen surface is composed of small precisely embossed optical ele«| ments to reflect perpendicularly incident light rays within a useful vertical included angle of 60° and a horizontal angle of 100°. Within these limits the reflection factor is relatively uniform providing good viewing from all seats of the average theater. By this device, the apparent screen brightness, with a given incident intensity, is increased by two times. One pattern is used for essentially head-on projection and the other, a tilted element pattern, is useful for high-angle projection. In all installations it has been found desirable to hang the screen on a curve whose radius is that of the projector throw. The screen carries the trade name of Miracle Mirror. This screen material, 340 May 1954 Journal of the SMPTE Vol. 62