British Kinematography (1952)

July, 1952 KNOPP : PRESIDENTIAL ADDRESS 13 Within studio installations, imperforated tape is used to some extent for nonsynchronous sound, but perforated magnetic film is normally employed for all synchronous work. Synchronising procedure is the same as that employed for photographic recording and indeed, many of the recorders used appear to be photographic machines which have been converted to the magnetic system. For location work, the sound recording truck fitted with a studio channel (or a simplified version of it), is still used for some types of work, and transportable sprocket driven magnetic recorders have also made their appearance. I note, however, that unperforated tape is being used on an increasing scale, and several feature studios, together with the majority of small production units specialising in location work, now use equipment employing this medium. Early difficulties in synchronising have been overcome by one English company, which has developed an ingenious system employing a pulse modulated control track. This track is recorded alongside the speech track. The pulses on the control track are derived from the associated picture camera and represent the frames turned by it, thus ensuring that synchronism is as precise as with the more conventional perforated tape. By operating both picture camera and sound recorder from separate local batteries, no A.C. need be generated for synchronising, and the whole equipment is kept light and portable. Thus, in both studio and location sound recording, considerable advances have been made towards higher efficiency and lower operating cost. At the present time magnetic recording is used as an intermediary step in the production of sound films and the sound so recorded is transferred photographically onto release positives. Time is not far distant, however, when magnetic recording may be used exclusively. Already it is being widely employed on 16mm. film and there are projectors on the American market fitted with both magnetic and optical sound heads, Such a projector will be available in this country within the next few months, and this innovation will mark another forward step towards higher fidelity. The Intensification Process Manufacturers of film stock are already alive to this development but I think you will agree that the greatest progress that has been made by these manufacturers is the latensification process which is now past its experimental state and is a trustworthy and reliable means for increasing the sensitivity of film stocks. Much research work has been conducted on photographic emulsions and one British company has now succeeded in producing an emulsion having a speed of 400 Weston or 37° Scheiner, which is 4-5 times faster than any known product. This emulsion is not at the moment available on kinematograph film but it is hoped, as work further progresses, that it will become available. Safety Film It may be reported that the production of cellulose nitrate film in this country has altogether ceased and except for a small quantity of nitrate film being imported by a Continental manufacturer, all new positive release prints are on tri-acetate base. It has been stated that only 1015 per cent of film at present in use is on cellulose nitrate base and the time is fast arriving when it will be to the advantage of the renting and exhibiting sides of the industry to get together to agree mutually to the exclusive use of safety film. Such an agreement would involve reprinting some of the older films that find their way out of the industry's archives on Sundays but this would not be a costly matter when compared with the advantages that would accrue. It must be remembered that a new Cinematograph Bill is at present making its progress through Parliament and before the close of the present Parliamentary session we shall have a new Cinematograph Act ; this is an enabling Act and gives the Home Secretary powers to publish regulations for safety, etc., and it will be materially to our advantage