The motion picture projectionist (Nov 1931-Jan 1933)

16 Motion Picture Projectionist December, 1931 possible, but since these are not yet available for motion picture work, they may be ignored for the present. Two Color Processes All professional work to date has been done on so-called "two color" processes, due to the relative simplicity of the problem as compared to true three color. It should be understood that a two color process, by its very nature, is incapable of reproducing true natural color. Twocolor processes are, at best, approximations of natural color, and can never be anything else. Great care has been exercised in choosing the two colors to be used, with the result that orange-red and blue-green are universally accepted as representing the best that can be done without the third element. In choosing the orange-red and blue-green combination, it has been first assumed that the two colors used must be capable of producing both black and white, with a complete scale of grays, these things being very common in nature. Since people are most interested in other people, it was necessary that a good approximation of flesh tones be produced, as well as of hair texture of the several complexions. The combination used happens to meet these requirements, and at the same time give fair foliage tints, earthy browns, and brilliant reds. It is of interest to note that these are all approximations, at best, except where the original tints happen to coincide exactly with one or the other of the color registers. By the law of averages, the chance of such coincidence is nearly zero. The Complexity of Color It is to be hoped that the reader will not be confused by the circle diagram herein represented, since it will fall far short of explaining the true situation in color mixing. From a scientific viewpoint, there is much in color which is still unknown. Each branch of science has its own method of representing color graphically, and no real agreement has been reached on the subject. The science of psychology favors the interpretation offered by the "color pyramid" shown in Fig. 2. It is claimed that every possible color, of every possible intensity, may be found in or on the pyramid. Consider the pyramid as a solid, in which each particle represents a given proportion of color and intensity. This diagram is offered here, not as a practical scheme for comprehending color film processes, but as an indication of the infinite complexity of color and color combinations, in the hope that the reader will have sympathy and understanding of the magnitude of the problem which faces those patient researchers in motion picture photography in color. (To be continued) Perfect Changeovers By M. H. Goldberg SINCE the adoption of the Standard Release Print and its acceptance by all members and divisions of the craft there has been much discussion regarding its advantages and its disadvantages. Champions of the standard cue marking and footage were of the opinion that individual marking of the film for start motor cues and changeover cues would be a thing of the past — that punch marks, chalk marks, clicker patches, foil contacts, and scratches would no longer disfigure the ends of the reels. While these conditions are indeed greatly lessened, there is nevertheless a great deal of film disfiguration still in evidence. Causes of Disfiguration An investigation of the situation reveals that this practice of individually marking film ends is attributable to several distinct causes. The principal cause is that of fear — fear that the dots will run through without being seen. To obviate that fear, projectionists have marked their reels for better visibility. Other reasons for the practice may be listed as: Timing for the difference in the pickup speed of various machines. Difference in technique. Individual practice and preferences of projectionists on shifts and differences among shifts. The cutting and removal of film, either on cues or after. Indecision caused by a variety of scratches, punchings and other markings put in during many runs. A New Method These are a few of the many causes which really should not affect operation, but which in practice very often do so. In the breadth of this country there are without a doubt many personally made devices and personal methods most of which tend to disfigure the prints. If these can be replaced by a method which will reduce disfiguration to an absolute minimum, even permitting the size and the number of the present dot markings and at the same time affording the projectionist a positive means of identifying them for start motor and changeover cues, then it must be admitted that a great forward step has been taken. Such a method may, it is believed, be found in the use of the GoldE Three Alarm. The device consists of three duralumin arms, light, strong and durable. These arms are provided with adjustable rollers and a locking device for micrometer setting. The arms are mounted on a bearing arm which in 1;urn is pivoted the mounting plate with a spring locking pin. The entire assembly is easily fastened to the inside of the upper magazine and is so designed as to permit the use of the largest size reels. The parts are accurately machined and the whole becomes in effect a micrometer caliper for three diameters. In operation, three distinct alarms are given, one as each arm drops against the side of the magazine. The first alarm is a general warning, the second is the start motor warning and the third for the changeover. The mechanism is simple and positive in operation and requires only a first survey of the reels used. Reel Hub Sizes The warnings are pre-set for the particular equipment's pickup speed and the diameter of the reel hubs in use. The hub diameters must of course be exactly alike for the method to work. A method has been developed for checking and correcting reel diameters which, once the operation has been performed, need never be repeated. Reel hubs have been checked in hundreds of theatres. Two general diameters have been found, namely, two-inch hubs and five-inch hubs. The five-inch hubs as manufactured at the present time are accurate and applicable to the Three Alarm method. Where a variety of hubs is used, a method has been devised for building up the diameters. Reel diameters may be simply and accurately checked by cutting a length of film which will exactly meet and butt when wrapped once around the hub. As may be expected, the length of the film from the changeover to the end of the reel must be alike on all reels. It has been found that each film manufacturer has adopted a trailer which is standard for the reels which he produces, in fact, the length of film from the changeover to the end of the reel is kept surprisingly close by all film manufacturers. It is expected soon that a common standard will soon be adopted by all film companies. Present Limits Satisfactory Even at the present time the GoldE device will operate with entire satisfaction within the limits established. In exceptional cases, a little checking on the part of the projectionist before the first show will enable him to see that all reels are alike. This is merely a matter of counting the turns of the reel or the rewind handle from the changeover to the end of the reel. A variation of two feet or less will not interfere with the operation of the alarm. More or less variation as between subjects or features, when running more than one, can be equalized on the film.