The motion picture projectionist (Nov 1930-Oct 1931)

March, 1931 Motion Picture Projectionist 11 Won Naxdxoff Colob M/xer. Figure 6 A/aus£. COIOXED &LT£#S we should be able to distinguish its color as red, but when placed before either of the other colors, we should be unable to distinguish its true color. If, on the other hand, we do not get a test from either of these methods, we can safely conclude that the sample is that of some intermediate hue. In the careless observer's mind, the , false notion exists that the mixing of colored pigments is directly comparable to the mixing of colored lights. It is common experience for a painter to mix blue paint and yellow paint to produce some final piginent like green. But, to try this with colored lights produces a different effect. Let us consider the color disc in Fig. 5, upon which we can mount two cardboard semi-circles, one colored blue and the other colored a particular hue of yellow. Upon rotating both semi-circles at a speed which slightly exceeds the limit for persistence of vision, the result would be a gray rather than a green. The explanation of this is psychological. Since certain regions of our retinas are sensitive to particular colors, we fatigue the nerve-endings that are sensitive to that color. Now, since we see each color for an equal length of time, the nerve-endings for these colors become equally fatigued, resulting in a gray effect. Returning to mixing pigments, on the other hand, the reason for the resultant green is due to reflection back and forth between the differently colored particles, which results in the absorption by the opposite pigments of many of the colored rays, and leaves a single wave-length which produces the visual sensation of green. Eastman New-Type 'Fast' Film ANEW type of motion picture film, about three times as "fast" as that previously in use, has been announced by the Eastman Kodak Company and has been demonstrated to a group of leading camermen and laboratory technicians. The new film is expected to work marked changes in studio technique, by permitting greater freedom in making sound pictures and by cutting down the necessary amount of lighting, thus reducing heat, glare, and cost. The faster film is described by motion picture engineers as the greatest advance in motion picture materials since the introduction of panchromatic film eighteen years ago. The motion picture industry, subsequent to that development, went over almost entirely to panchromatic film, which, in monochrome, portrays colors in their proper tonal relation to each other instead of with distorted values. The new type of film was announced as possessing increased panchromatic qualities in addition to its greatly increased "speed." Increased speed, in cinematographic terminology, means simply the ability to expose a photographic image with less light. Since the advent of sound in motion pictures three years ago, the Eastman Kodak Research Laboratories have experi mented in the direction of developing a film to meet present conditions in the sound studios, where the substitution of incandescent lighting for electric arcs presented a new photochemical problem. The panchromatic film heretofore in use was developed for exposure with arc lighting. When the change to incandescent illumination swept over Hollywood, the film was adapted to the new conditions so far as that was then possible. The new type of film, on the other hand, was specially made for use with the "inkies," as Hollywood calls incandescent lights, and has a sensitivity to red and green hitherto undreamed of. Incandescent light contains a higher proportion of red than does the light from arcs. The increased speed and extraordinary color sensitivity of the new film are expected to be of particular usefulness in natural color photography, where the great concentration of light hitherto necessary has been a drawback. Another practical advantage claimed for the supersensitive film by Eastman representatives here is an increase in the possible "depth of focus" in sound film photography. The use of incandescent lighting made desirable the wider opening of lens diaphragms to let additional light into the cameras. This, in turn, by a law of optics, greatly diminished the range within which the actors could move and yet remain in focus. When sound came to the movies, depth of focus became of increasing importance because it is irritating to audiences to hear a clear voice coming from an out-of-focus actor. With the greatly increased speed of the new film, it will henceforth be possible to "stop-down" lenses, increasing the depth of focus and thus permitting greater latitude to directors in moving their actors about before the camera. The characters will no longer have to remain in a narrow plane at a fixed distance from the lens under penalty of blurring into the background or becoming fuzzy in the foreground. An alternative advantage of the new type of film is the possibility of reducing the amount of light to onehalf or one-third the present quantity necessary for sound picture cinematography. In practice, it is expected that the studios *will compromise between the maximum reduction of lighting and the maximum gain in depth of focus, taking partial advantage of both benefits offered by the new type of material. A further characteristic of supersensitive panchromatic film is the greater ability it will give newsreel cameramen to make pictures under difficult conditions, both at night and in daylight insufficient to make clear pictures on film of the speeds previously in use. Prize fight pictures, taken under incandescent lights, will be better, and previously impossible indoor action scenes like hockey games and basketball games will become possible. Successful motion pictures of action on a theatre stage, photographed from the balcony, were made during the tests that preceded announcement of the film — a feat considered difficult. Decided "development latitude," minimizing the danger of making films "chalky" or "over-contrasty" in processing, is cited as an additional quality of the new film. The sensitive "emulsion" of the new film is very closely related to one prepared for astronomical photography, as well as to super-speed panchromatic plates put into use by newspaper photographers during the past few months for action photography under artificial lights. This fact was revealed by Dr. C. E. Kenneth Mees, director of the Eastman Kodak Company in charge of Research and Development. Astronomers, it has been learned, used the new emulsion recently in making observations seeking to discover whether there is water in the atmosphere of Mars. The necessary time for exposing plates in the spectroscope was reduced from ten hours to four in the observations in question.