American cinematographer (Aug 1933)

134 American Cinematographer 0 August 1933 The new Teague mobile process projector. A Super-Portable Background- Pro|ector by Frank B. Good, A.S.C. W ITHIN the past two or three years, the “trans- parency” or projected-background process has revolutionized the art of trick cinematography, and effected tremendous savings in production-cists. Its basic principles are too well known to merit repetition be- yond the simple statement that the process consists of the projection of any desired cinematographic background upon a translucent screen behind the actors, with background- projector and camera operating in an electrical interlock. This process has literally made possible the making of sev- eral of the most successful productions of the day, and has saved hundreds of thousands of dollars—and incalculable time and effort—in its application to other productions. It is probable that nine productions out of ten contain at least one transparency sequence— and in a majority of in- stances, more than one sequence. Heretofore, however, this process has suffered from the fact that most transparency instalations have been of the fixed type, and accordingly, confined to a single stage. In natural consequence, the scheduling of process sequences in a large studio has become increasingly difficult. To re- duce this congestion, process technicians throughout the industry have been experimenting with the development of portable transparency installations, with varying degrees of success. The latest—and probably the most successful—of these is one recently developed by George J. Teague, one of the pioneers in transparency work. In designing this equipment, Mr. Teague (who will be remembered as one of the designers of the equipment first used for projected-background work, and associated with the process department of the Fox Studio on all process work from the first examples in “Liliom’’ and “Just Imagine’’ down to such recent productions as “State Fair’’) has had in mind the ideal of creating a background-projector as portable as a modern blimped camera. In attaining this end, however, he has taken pains to attain equal flexibility combined with the greatest rigidity and precision. As can be seen from the illustration, the projector is mounted on a wheeled base, fitted with pointed jacks by which it can be rigidly anchored to the stage-floor. Above this comes a geared hoist, by which he projecion-head can be raised or lowered in a vertical plane, and locked rigidly at any point. Above this is a firm base fitted with ad- justments by which the projection-head may be tilted or revolved to any desired position; the-tilt giving a range of 20° each way from tne horizontal, and the revolving head allowing a full 360° swing. Both of these movements, of course, are also fitted with positive locks, so that the pro- jector, though easily adjusted, is held rigidly in place when in use. The lamp-house is mounted on a rigidly-cast gib, which can be slid forward and back in absolute optical alignment and with the projection lens, or instantly removed. This movement, too, is fitted with postive locks. The projection-head itself is extremely compact, yet rigid. Registration is secured by the Technicolor method. The shutter—balanced with extreme precision, and allowing the maximum opening—it is behind the film apereture. The projector is powered by an interlock motor, placed on the right-hand side, and fitted with a simple connection allowing an exceptional degree of adjustment for synchronization with the taking camera. The whole mechanism is rigidly fitted into a finely machined base-plate, and demountable by re- leasing a single bolt and disconnection of the motor-shaft slip-joint. By this means, if it is desired to fly the equipment, the head and lamphouse can be removed from the base in a matter of seconds, and reassembled in an equally brief interval. The lamp-house is a standard, high-intensity projection mirror-arc type; this is an integral part of Mr. Teague’s design. Only, he says, by absolute co-ordination of all of the optical units of the projector can the maximum effi- ciency be attained. In a majority of installations, he points out, the lamp-house is considered solely as a light-source, not as an intergral part of the optical system. Accordingly, though transparency-technicians frequently change the focal- length of the projection-lenses used, according to the re- quirements of the scene to be made—but use the same reflecting-system at the light-source throughout. This prac- tice, he has found, is in a large measure the cause of the “hot-spot” which so frequently causes trouble in this work. Accordingly, he has gone to great pains to co-ordinate the foci of the mirrors used with the foci of the projection- lenses employed; he has, moreover, found it imperative to use mirrors and lenses of the same manufacture. By this (Continued on Page 148)