International projectionist (Jan-Dec 1948)

FOREWORD : Eighteen months ago it was revealed exclusively by IP* that film manufacturers, notably Eastman Kodak Company, had developed an acetate film support to the point where it could challenge the long-standing supremacy of nitrate film for use as release print positive. Subsequent developments, including the circulation of several featurelength releases on acetate stock, induced widespread comment reflecting sharply conflicting opinions among projectionists concerning the relative merits of these two film supports. Although the new acetate base won some degree of acceptance, projectionist opinion in the main was distinctly unfavorable. The situation was not aided by the rather inept manner in which the first acetate prints were distributed, with many theatres not even having the proper splicing fluid on hand and thus sustaining a series of delays and damaging film breaks during performances. The overall picture was one of confusion compounded largely of a lack of information about and the difficulty experienced in handling the new film stock. During the past year further improvement in the quality of this new acetate base and the assurance of greatly increased production made it obvious that the days of nitrate release prints were numbered. Because of the prime importance of this topic to projectionists in particular and to the industry in general, IP held it to be imperative that all the facts relative to the situation be thoroughly investigated and weighed objectively by means of an impartial independent survey. The results of such a survey are given in the appended article. * "Acetate Stock to Supplant Nitrate. "' by Henry B. Sellwood; IP June, 1947, p. 5. Safety Film: Projection Factors SAFETY Film for release print positives has definitely arrived and it is only a question of the length of time required for the expansion of present manufacturing facilities until it supplants the nitrate release prints now used almost exclusively in the professional motion picture field. Moreover, this new Safety Film need not be the beneficiary of any indulgence by its users, for there exists ample evidence to warrant the belief that in terms of the printing, processing and projection operations it compares favorably in every important respect with nitrate stock. This is the considered opinion of the writer following an exhaustive investigation which included the observance of every procedural step incident to all three operations aforementioned, in addition to the examination of all available data at the manufacturing end. Inclusive Investigation Made This latter activity was made possible through the cooperation of Eastman Kodak Company in making available all facilities of Kodak Research Laboratories for a thorough-going, on-the-spot independent checking of all test data from its laboratories and from theatres of varying classification as to run, physical characteristics, operational procedure and type ol projection equipment used. No restrictions of any sort were imposed as to type or variety of tests in either laboratory or theatre, and it is the writer's belief that the data thus adduced would match almost exactly the conclusions that would be reached by any other impartial observer amid different yet comparable surroundings.1 1 As a matter of fact, this new acetate film has never been cloaked in secrecy. A straightforward exposition of the relative merits of this film base and standard nitrate stock was given before the Spring 1948 convention of the SMPE and is now on view for all the world to see in the October issue of the Society's Journal: ''Improved Safety Motion Picture Film Support," by Charles R. Fordyce, p. 331. By HENRY B. SELLWOOD A word anent correct nomenclature. The new acetate film is known in the laboratory as "High Acetyl Film 5302," in commercial circles as "Release Positive Safety Film,' while operational crews refer to it simply as "Safety Film." This latter term is used throughout this article. Projectionists in general seldom concern themselves with the various phases of processing and printing of motion picture film, yet these production steps have a very important bearing upon the quality of the image that is projected onto a theatre screen. Important Processing Factors In processing, for example, the degree of swelling of the film which occurs during the developing step is of prime importance. If the longitudinal swell is too rapid or too great, some processing machines encounter trouble from excessive slackness which allows the film to be displaced on the bottom rollers. Likewise, excessive swelling during development may result in correspondingly excessive shrinkage at the beginning of the drying operation. This has been a difficulty with previous safety films, not only because of the magnitude of swelling but also because of the very rapid rate of shrinkage of the Safety Film upon drying, causing rapid building up of tension in a critical area. Of importance also is any tendency of the film to curl too highly negative (away from the emulsion ) at the beginning of drying, or .too highly positive (toward the emulsion) when completely dry. The new Safety Film, while exhibiting an appreciable amount of swelling, has a comparatively slow rate of shrinkage upon drying, which tends to reduce the possibility of excessive operating tensions. Tests carried out in two commercial laboratories, each test involving several thousand feet of film, gave no indication on any of the machines of greater tension than normal (Table A). Likewise, in none of the tests did the swelling during development cause difficulty from slackness. Duplitized Film Processes There exists a widespread misconception regarding the nature of the film support used for various color processes, namely, Trucolor, Cinecolor and Magnacolor. All three of these processes employ duplitized cine film which carries emulsion on both front and back surfaces. However, and this is important, of these three only Trucolor releases are printed on acetate safety stock, the other two employing standard nitrate release positive. Trucolor prints (distributed by Republic Pictures) has had first call upon practically all the acetate film available up to this time. Oddly enough, and seemingly indicative of the power of suggestion, projec TABLE A. Results of processing tests of safety film in commercial laboratories. Macnine Threading Laboratory Length Drying Conditions A 1,750 feet 77°?. <f2?S H.K. B 2,120 feet 63°F. 6o£ R.H. -ipprcxinate Feet of Test 12,000 Filni Curl at Rewind Difficulties + .CC" + .14" INTERNATIONAL PROJECTIONIST • November 1948