Movie Makers (Jan-Dec 1930)

IMO^ME l»ajm.H.EKKS is darkened. The last thing to be done before turning out the white light for the actual start of development is to see that every needed piece of equipment is in its proper place and that the temperature of the solution is reasonably close to sixty-five degrees, that is, between sixty-three and seventy degrees Fahrenheit. Actual Development. The rack is placed upon its support. For example, in the case of the spiral rack, it is placed upon the winding pin which has previously been attached to the table. The film is wound upon the rack in such a manner that the only contact with any supporting surface is upon the celluloid side. The emulsion is thus left absolutely free and exposed to the action of the solution. When the rack is filled, it is immersed in the developing bath and then raised and dropped three or four times to remove all air-bells. During the development process, the rack should be slightly agitated at intervals of approximately thirty seconds. When development is completed, as indicated either by a time and temperature factor for the developer being used or by the appearance of the film itself, the rack with its film is lifted from the solution. It is allowed to drain a few seconds and then the entire rack is placed in the second tray which contains pure water or water containing a slight amount of acetic acid. This rinsing need not take more than a second or two. The film is then placed in the tank of hypo and left for about fifteen minutes, if negative, or for about five to eight minutes, if positive film. It is then removed from the hypo and placed in the tank of water. A continuous stream of running water is allowed to flow into the tank and overflow across the edges for a period of approximately one-half hour. After Treatment. When the film has been thoroughly washed, as explained, it is ready for drying which should be done in a room as free of dust as possible. It is placed upon a supporting surface such as a wire screen. From either spiral rack or the pincross rack the film can be removed in the form of a loose spiral. By immersing in just sufficient water to cover the film this spiral may be rapidly tightened into a comparatively compact coil. If the film is removed from the water in this condition, the closely adhering turns of the film in the coil force out most of the surplus water. The end of the film is now attached to a drying rack or a small wooden drum and by rotating this drum or rack the film is wound upon it. In carrying out this operation it is essential that the film be wound with the emulsion side out and the turns be made rather loosely. The film shrinks while drying and, if wound too tightly upon the drum, this shrinkage will cause it to break. In the absence of such a rack or drum, the film may be suspended from any convenient support in long loops. All surface moisture should be removed with a pad of absorbent cotton. This will prevent uneven drying, remove foreign matter and tend to eliminate the difference in film density due to the lower ends of the loops drying less rapidly than the upper ends. When the film is thoroughly dry, it is wound loosely upon a spool. This is placed upon a film rewind. Two pads of heavy chiffon-velvet, chamois skin, or absorbent cotton wrapped in surgical gauze are saturated with carbon tetrachloride, although there should be no free excess of the fluid. The film is held firmly between these pads and wound from one reel to the other. Two or three repetitions of this process should remove all drying marks and other foreign matter from the film, leaving it perfectly clean and burnished, ready for printing or projection. Before concluding, it is advisable to include a little information regarding the control of development. The system in highest favor at the present time, and one which certainly has many points to recommend it, is the so-called time and temperature system. This is based on the fact that a developer of given dilution, allowed to act for a definite length of time at a definite temperature, will produce a definite re sult in the emulsion. Most developing solutions are supposed to be used at a temperature of sixty-five degrees Fahrenheit. Developers of such strength that they will produce full negative development in about fifteen or twenty minutes at this temperature are the most widely used for ordinary purposes. Many formulae, and, in fact, all of them intended for tank developers, have the time and temperature factor given. Motion picture negative film may be developed in almost any good negative developer, although the metol hydroquinone combinations are the most popular. The very finest quality is obtained tlirough the use of a developer such as glycin and, although this is a developer which is supposed to be difficult to use, the fact is that it presents few, if any, more difficulties than the more prominent developers. When a glycin developer is used, it may be used in a dilution requiring from thirty to forty-five minutes for development. On the other hand, positive films are almost always developed in metol hydroquinone at a strength which will give complete development in five minutes or less. Another method of control is the visual method. Although this is excellent in the hands of those who have had considerable experience in photographic development, it certainly is not a dependable method of control for the beginner. Very little advice can be given regarding the appearance of the developed image, although, an old-time rule is that the film is ready for fixing when the image is plainly discernible upon the back of the film. Those who expect to control development by visual means should devote at least one spool of film to experimental work. This should be exposed and developed in five foot lengths. Each piece should be fixed and dried before the next is developed and, if possible, tried out in a projector. The development of twenty five-foot pieces of film will give far more important and valuable information than could be imparted in a volume of written instruction. It is quite possible that the first trial at development will not be entirely successful but, certainly, after developing one or two rolls of film the amateur should have no further difficulty in this work. Those who wish formulae for motion picture developing can secure them by writing the technical consultant of the Amateur Cinema League.