British Kinematography (1952)

48 BRITISH KINEMATOGRAPHY Vol. 21, No. L._ i — CONTROL AND PRODUCTION DESK tube. A few inches from this tube was the film camera and its associated sound head, sound being brought through from microphones in the Chamber in the normal television manner. The camera records both vision and sound on 35 mm. film (16 mm. can be used) and the Kinescope process starts. From the camera the film passes through a series of tanks which completely process it. At the end of the process, which includes drying, the film goes through a projector for monitoring purposes, and is then wound to its final reel (see Fig. 1). Only ninety seconds elapse from the time a frame passes before the cathode-ray tube until it is wound on the reel. The equipment is made up of three basic units. First there is the high definition television monitor capable of displaying H h a positive or negative picture on the cathoderay tube. This change is achieved by simple reversal of polarity. The unit includes an electronic shutter as an integral part to allow the 30 frame (in Britain it would be 25 frame) television signal to synchronize, or resolve, to the motion picture rate of 24 frames per second. This monitor can, of course, be adjusted to receive any television standard of line and frequency. The circuits are designed for a bandwidth of 10 megacycles but can easily be adapted to take higher definition standards. The function of the electronic shutter is to blank out the cathode-ray tube at appropriate intervals in order to synchronize with the pull-down of the shutterless movie camera ; it is completely automatic and assures one complete television frame being exposed on one film frame. The polarity of the picture (positive or negative) is controlled by one switch while simple controls adjust for non-linearity of incoming signals, for brightness and contrast. The second unit is the shutterless cameras td and its associated film magazine which contains 12,000 feet of film. It also incorporates a newly designed sound-on-film recorder which has no moving parts. The 12,000 feet of film will give continuous recording for over two hours. The sound track is a variable density type and sound fidelity is limited only by the reproduction system in a theatre. This unit photographs the image on the cathode-ray tube of unit 1, and records the sound passed through the microphones. This produces a completely exposed single-system film. The third unit is a high-speed processing machine designed to develop, rinse, fix, wash, and dry the exposed film at synchronous sound projector speed of 90 feet per minute, 24 frames per second, using high temperature, high pressure spray PROCESSING UNIT PROJECTOR D r^-0 Fig. 1 . Layout of the Kinescope. techniques. Fast drying is accomplished by means of squeegees and hot air and the film quality, using these techniques, is equal to or better than standard release quality. At the end of the processing chain the film can, if required, be passed through a projector for theatre use or monitoring before being wound on its finished reel. The complete process is automatic — one control starts the camera, process machine, theatre or monitor projector, and final wind. All temperatures are thermostatically controlled and all components are interlocked to ensure simultaneous stopping and starting. The film normally used is standard 35 mm. fine grain and packaged chemicals allow unskilled operators to take charge. Physically the whole unit takes up 60 square feet of floor space and can be situated (in a theatre) anywhere near to the projectors.