The Cine Technician (1943 - 1945)

12 THE CINETECHNICIAN FINE GRAIN by JOHN A. OJERHOLM March— April, 1943 ■I ALREADY in Britain, even' in the midst of war, motion pictures have been shown which reveal a marked advance both in the definition and relief of the image, and a remarkable increase in the frequency range of the sound recorded on the sound track. There is a definite step in the direction of stereoscopy, an increase in volume, and a clearer sound definition. These advances have been made possible by the use of fine-grain film, either in the studio, or the positive processing plant, or in both. Finegrain film has, in fact, quietly, behind the noise of war, brought about, not a revolution, but emphatically an incalculable reform in the technical reaches of the motion picture. Fine-grain recording is not being operated in England to-day, but fine-grain dupes and lavenders are being imported here increasingly. On these the increased visual definition, and the greatly improved sound, has been reported and saluted in the columns of the trade press without exception. Fine-grain has come to stay. It will inevitably be used here, in British laboratories, in the postwar period. It is being increasingly used for dubbing prints. A naturally progressive step in the march of the modern motion picture, its forward movement is an inevitable as was sound and colour. What then is fine-grain? Whence did it come? What are its precise technical achievements? What are the exact relations of fine-grain in studio recording, photography and laboratory printing in the picture theatre itself? These questions are easily answered. Look at a fine-grain film as projected to-day, and the technician will see, less boiling of the image, because of the greater resolution of the fine-grain film. Where fine-grain film is used for dubbing, he will find that the use of it in printing has brought a material advance in volume range, which permits greater latitude in the original recording. There is an improvement in sound quality because of the reduction of noise and modulated noise effects which, it is well known, tend to mask the signal, where coarser grain types of emulsion are used. Both ear and eye, in fact, are given a closer contact with reality. For years past the limitations of the older and established types of emulsion have been recognised, and the need for a finer-grain stock never needed argument. The use, nowadays, of finegrain stock for dubbing and release prints, in addition to its use on master positives, duped negatives and back projection prints, has brought about a solution of that problem. The normal type of film emulsion in general use to-day has a coarse grain structure. As a consequence, sound prints are subject to much extraneous noise, modulated noise effects, loss of high-frequency resolution, image spread, halation, and other deficiencies and defects. Picture prints have marked limits of definition and clarity. Early experiments, dating back to 1937, with fine-grain, on duplicating and back projection prints, led to the belief that if suitable films of this type were applied to recording and release printing, there would be material improvements. Experiments, dealt with more exhaustively below, were launched in Hollywood, fruits of which are being harvested in England to-day. Numerous devices have been essayed and perfected by motion picture technicians, aiming to reduce the basic film noise of positive type emulsions. Noise reduction equipments, push pull recordings, track-matting devices, wider original sound-tracks, pre and post-equalised push-pull recordings, have all been tried. Ultra-violet printing of sound track, on positive type emulsions, was found to bring about some reduction of film noise, as well as improving the high-frequency response, and reducing halation. It is the only method, in fact, which basically affects the source of film noise. First experiments with the use of fine-grain film were made in the studios of Hollywood. Since 1938 research and experiment has been carried on by ERPI and Paramount, with a view to using fine-grain emulsion for variable density negatives and re-recording prints. Metro have adopted the fine-grain stock for all purposes. Goldwyn Studios experimented with both Dupont and Eastman stock. For some time all re-recording prints at Paramount have been made on fine-grain stock, from a normal sound negative, and one complete picture was re-recorded on fine-grain release negative, with a limited number of release positives printed also on fine-grain. These were, in fact, the first complete adaptations of fine-grain stocks to release. Simultaneously, ERPI have been constantly active in investigating the sensitometric proper