International projectionist (Jan-Dec 1952)

volume xxvn OCTOBER 1952 NUMBER 10 Theatre release prints on safety film stock are today an accomplished fact. A six-year span of consistently good performance has gained for this new film base widespread industry acceptance. Six years ago, in presenting the first authoritative series of technical articles on this film base, IP stated that projectionists were faced with a fact not a theory, and it added that the mark of true craftsmanship lies not in the medium employed but rather in the skill with which it is utilized. Safety film theatre release prints are here to stay, come what may, and it is in the best traditions of the projectionist craft that it use this film stock so as to achieve the best possible picture quality on the screen. This is no more or no less than an enlightened and an intelligent self-interest. — Editor Safety Film: Performance Characteristics MANY projectionists still hold tenaciously to the contention that safety film, despite several years of satisfactory service, has no place in the motion-picture theatre, and that use of nitrate stock should be resumed for the printing of release positives, no matter which kind of film be used in the camera or for master positives and duplicate negatives. The reasons given in support of this contention boil down to various complaints anent ease of handling and splicing, and picture-quality on the theatre screen. All of these complaints are worthy of serious consideration. The motion-picture industry has long sought a safe film. It is a quirk of fate that movies, until several years ago, have been made possible by running an explosively inflammable ribbon through an intensely hot beam of light. Such a condition as this has made projection a hazardous occupation. Nitrate Film and Film Fire Nitrate film is not safe even though it be left untouched in storage vaults. From the moment of its manufacture, nitrate film begins to decompose both chemically and physically. The insidious deterioration continues, hastened by repeated projections and improper storage conditions, until the film is no longer By ROBERT A. MITCHELL fit to use. Its kindling temperature, initially low, progressively decreases until the film is capable of spontaneous combustion during warm, dry weather. Can a blazing reel of nitrate film be extinguished? A carbon-dioxide extinguisher has a 50-50 chance because of the extreme coldness of C02 "snow"; but because nitrate film contains plenty of oxygen, in a loosely combined state with nitrogen, it can burn furiously even when submerged in water. The writer would not lift a finger to attempt extinguishing a film fire. Close the ports, turn on the house lights, break the arc (if you get a chance), and take off. After the film has burned itself out, ventilate the projection room thoroughly before making a survey of the damage or cleaning up the projectors. Thankfully, we need this advice less and less as safety film displaces nitrate film. Safety film won't burn in a projector magazine. In fact, it is difficult to make it burn at all when rolled up on a reel. All attempts to produce an acceptable safety film made prior to 1946 have been rejected by the trade because the safety films offered were physically unsatistory for machine processing and for repeated projections via arclamps of high power. These early safety films shrank, buckled, and wore out very quickly because of brittleness. Picture-quality on the screen accordingly failed to measure up to the high standards set by nitrate-film performance. Since picture-quality was, and still is, the vital consideration, not one of the early safety films was able, on its own merits, despite the absence of fire-hazard, to displace the dangerous and chemically unstable nitrate theatrerelease positive film. The Old (Diacetate) Safety Stock Now what about the quality and properties of modern safety film, known as "triacetate" film, or, more correctly, as "high-acetyl" film? Is it satisfactory? Does it compare favorably with nitrate film in performance? Exactly what are the objections so many projectionists raise against it? Considering the unhappy fate of earlier types of safety film, it would seem that we projectionists are judge and jury in the case of nitrate vs. high-acetyl safety film. Picture-quality, we repeat, is still more important to the motion-picture industry than complete reduction of the risks involved in the manufacture and use of its photographic and sound records. Projectionists, acutely fire-conscious, feel the same way toward the matter. The points to be considered, therefore, are INTERNATIONAL PROJECTIONIST • October 1952