International projectionist (Jan-Dec 1948)

the outside of the film, these have heen tested by the Bureau of Standards. Chemically we have found that none of these things add to the life of the film. As to mechanics and to wear and tear on the film, that is another matter. Q. What percentage of the films have you had to duplicate because of incipient and partial decomposition? A. A considerable body of film has deteriorated because we were not able to duplicate because of lack of funds, equipment and personnel. In many cases, when the film was brought out of storage, unwrapped and unwound, the moisture in the air immediately precipitated deterioration ; overnight, almost. Advocates Equalization of Temperature We have developed tempering techniques, bringing the film out and letting the temperature rise §lowly by radiation. Care should be taken to prevent exposure of the film to the air until the temperature of the film is in balance with the temperature of the air; otherwise condensation on the surface of the film will result. Q. To what extent do you plan to store the film at low temperatures — say, around 50 F. — and to what extent do you plan to isolate the films in individual compartments as against mass storage in a unit vault? A. Nitrate film of high record value we intend to store in cabinets, reducing the unit of risk to a minimum, perhaps one reel instead of a vault full of reels. We intend, for the same film of high record value, to maintain temperatures of about 50 F. and about 50% relative humidity. That is about as low a temperature as people can work in. We will have the tempering cans in which we will bring the film out of the vaults, set them in the workroom, and let radiation lift the temperature so it will be safe to unwind the film. Film of less record value can be stored without the cabinets. However, our entire program contemplates the transfer of record film to acetate stock as fast as funds will permit, so all record film will ultimately be on safety stock, which has a much longer life than nitrate film. Estimated Film Life in Storage Q. Has any estimate been made as to the life of the film in storage? A. Three to five hundred years for acetate film, at which time it can be copied and perpetuated for perhaps three to five thousand years. Q. Has any progress been made in the transfer of images to metal films? A. It does not seem necessary. The only metal used above an experimental stage has been aluminum which will pit under the influence of sulphur fumes. It also is faulty in that it crinkles and has to be ironed out. It is also opaque and projection has to be by reflection; but so far no other metal has been used widely. When acetate film has preservation characteristics better than the best rag paper, we do not feel the need for metal. Q. Anent the vaults in The Archives Building, are the cabinets of 18-8 stainless steel, and have you observed any corrosion of the metal? Will it be necessary to construct them of molybdenum stainless steel instead of ordinary 18-8? A. The cabinets are of molybdenum stainless steel. There has been some corrosion on them owing to the fluxing material when they were welded and fabricated. However, that is a seepage process which we believe will expend itself in a few years. We are simply wiping it off with lemon oil and watching it, but the main body of the cabinets themselves seem to be holding up nicely. A new cabinet has been developed, called the Cascade Cabinet, which can be made out of ordinary furniture steel at considerably less cost, can be thrown away when it rusts over a period of time, and be much cheaper than stainless steel. The latter cabinets cost us about $30 per reel to put the film away. Cabinets for eight vaults (about 2000 rolls) cost us about $60,000, which is much above the reach of the average film library. The Cascade Cabinet can be built for about $2 per roll (wholesale cost), and by painting and by having proper air we feel that they will not rust for over a decade at least; and at that time, if they did rust, new cabinets could be put in. They avoid insulation and other excessive expenses. Handling, Preserving 16-mm Film The handling and preservation of 16-mm acetate (safety) film introduces problems not encountered with 35-mm nitrate stock. To those who inquired about correct procedure for 16-mm stock, R. A. Mitchell, author of the original contributions on film handling, offers the following: Many modes of treatment effective for 35-mm nitrate film do not work well with acetate stock. Neither the late F. H. Richardson in his Bluobook nor I in my articles on the projection room handling of prints had 16-mm film in mind. 16-mm film is constituted differently chemically from 35-mm nitrate stock in that no camphor or similar substance is used in the manufacture of the Consolidate RCA Film Section, With Kreuzer Heading Group Consolidation of all RCA motion picture activities into a newly-created RCA Theatre and Recording Equipment Section has been announced. Comprising the Section will be the following groups: Theatre equipment, Film Recording, and Brenkert Light Projection Co. General manager of the combined groups will be Barton Kreuzer, who, joining RCA in 1928, has served successively in the development, engineering, installation, service, and for the past two years as head of film recording activities. J. F. (Jack O'Brien) will continue to direct sales of all theatre equipment, and Karl Brenkert still will oversee activities at the projector manufacturing plant in Detroit. Barton Kreuzer former, it all being acetate ("safety") film. Thus it appears doubtful that camphor could be used with any success for the purpose of lengthening the life of 16-mm prints. Safety film base has a much, greater capacity for moisture than nitrate base. When much of the absorbed moisture is lost by repeated projection or by exposure to excessively dry air, the film becomes brittle and in this state is easily torn or broken. In the case of 16-mm film, therefore, "humidifying" by some means whereby the film is exposed to a humid, or moisture-containing atmosphere is distinctly beneficial, although even this treatment won't prolong film life indefinitely. It is safe to say that 16-mm films will last longer if stored under proper humidifying conditions, but of course no one can say how much longer. Prints suffer greatly from ordinary use. Projection of 16-mm film by high-powered lamps greatly shortens their useful life. Wafer Tanks in Film Cabinets? What about water tanks in the film cabinets? Don't use them, Richardson notwithstanding. The risk of film damage is too great. Much better are the humidor-type film cans that have been on the market for many years. These cans are provided with blotting paper or other absorbent material in the covers. The blotting paper may be moistened with plain water or with a dilute solution of glycerine — the same kind sold at drug stores as a hand lotion. Glycerine has the property of holding moisture for a long time, and this retards the drying out of the blotting paper in the humidor film can. (Similar humidors are used for keeping pipe tobacco moist at all times.) If the films are not kept in individual cans, perhaps some arrangement may be devised for moistened blotting paper or absorbent cotton inside the storage cabinets used. Just be sure that there is no possibility of the film getting wet. I think some good will result from such an arrangement, even though reels are shipped out during the day. When films are stored for long periods of time — say, several weeks or months — great care must be used to prevent too much humidity. If the film "dews," that is, if tiny droplets of water condense upon it from the air, great damage may ensue. No matter what the film base is made of, dampness has a softening effect on the emulsion. We all know how easily emulsion scrapes off after having been dampened. I once purchased several reels of theatre film which had been stored in the vaults of a big film laboratory for more than ten years. The air in this vault — a large room in which the open reels are stacked on racks like books in a bookcase — was kept moist continually by tanks of water arranged in the old-fashioned "approved" manner. Although old, these prints had never been projected and therefore could be said to be "brand-new." But they had been so saturated with moisture that the emulsion had softened and the layers of film were literally glued together. Some kind of mildew which imparted a peculiar "peppery" odor to the film had attacked the emulsion along the edges. It required many hours of hard (Continue on page 30) 14 INTERNATIONAL PROJECTIONIST • May 1948