Journal of the Society of Motion Picture Engineers (1930-1949)

on the enclosure for the picture projection tube and on various components of the amplifier and control equipment. It is extremely important that all of these safety circuits be intact at all times. Unauthorized modifications are the height of foolishness where potentials dangerous to life are concerned. FILM METHOD FOR THEATER TELEVISION PROJECTION This method, the so-called storagetype system, for television theater projection uses a 35mm motion picture camera to photograph a negative image on a television receiver to produce a direct-positive print. The exposed film is transported continuously to equipment for rapid development and drying. From this equipment it is transported to the projector for immediate projection on the theater screen. The elapsed time from the television camera pickup at the scene of action to the time of projection of the completed positive print on the theater screen is 61 sec. This method requires a properly ventilated room of fireproof construction for the television receiver, the 35mm picture camera with a magazine which may contain 12,000 ft of unexposed film, and for the developing and drying equipment. This room obviously must be adjacent to the theater projection room and provision must be made for feeding the completed positive print to the upper fire valve rollers of the theater projector, from which the upper magazine has been removed. This arrangement of equipment will provide a continuous projection of motion pictures on the theater screen for more than two hours' duration. From the viewpoint of safety, the present method used for feeding the processed print to and across the theater projection room to the projector head on a series of open pulleys could hardly be considered as complying with the most elementary standards for safe handling of 35mm film. With the take-up magazine and the take-up device on the projector designed for only approximately 2000 ft of film, it is obvious that cutting of the film at the end of each 2000 ft will be required. The running end of the film must quickly be attached to the hub of an empty reel and the excess film on the projection-room floor must be spun onto the hub, after which the reel must be placed into position on the take-up spindle of the lower magazine for taking up the succeeding 2000 ft of film. This procedure must be repeated five times during the continuous projection of 1 2,000 ft of film. Such a procedure does not appear to follow any of the longstanding practices for the safe handling of motion picture film. Conclusions Some of the safety hazards in theater and television studio projection rooms have been pointed out and the importance of adequate corrective measures has been emphasized. The special safety precautions developed over a long period for theater projection rooms have been shown to be sensible and desirable without regard to the ignition characteristics of the film used, and the same considerations are shown to be applicable also to television studio projection rooms. Special hazards in television studios have been outlined. Theater television equipment, which presents safety hazards of new types, has been discussed and attention has been called to some of these in the hope that full knowledge of them will aid in their eventual elimination. 218 September 1952 Journal of the SMPTE Vol. 59