Journal of the Society of Motion Picture and Television Engineers (1950-1954)

Color Television The NTSC compatible color television system made great development in 1953 under the continued direction of the various panels of the National Television System Committee. An NTSC color television demonstration was presented at the Hotel WaldorfAstoria, New York City, in October 1953, where 13 color television receivers, as produced in the United States, were placed in operation. The color pictures were viewed by many engineers, the press, industry leaders and others who are interested in the color television development. Late in 1953 the FCC approved the NTSC method, reversing its earlier approval of the CBS field-sequential system. NBC has been transmitting several of its regular shows in color. The transmissions have been picked up with excellent quality on standard black-andwhite receivers. The RCA color cameras used were equipped with three image-orthicon tubes, one for each of the primary colors. A one-tube camera is under development by RCA. CBS has developed a color camera which uses a single tube operating on a fieldsequential basis with a rotating filterwheel behind the lens. The signal then goes to a "chromacoder," a device which translates the signal into the NTSC standard. One of the techniques making up the NTSC system is described in the FCC Report and Order as follows: "(It) relates to the demonstrated fact that the eye is much less sensitive to changes in hue and saturation in small areas than it is to changes in brightness. The corollary is that as the size of the viewed object is reduced, the eye becomes progressively color-blind so that ability to distinguish hue deteriorates. It follows that the color components of a picture can be transmitted over a narrow band of frequencies since resolution of fine detail is a function of bandwidth. In the NTSC system faithful colors are transmitted over a 0.06-mc bandwidth while the monochrome or luminance signal is transmitted over a 4.2-mc bandwidth. In between is a twilight zone where adulterated colors are transmitted. Thus, faithful colors appear in the coarse areas of the picture, adulterated colors in the medium-fine detail and only monochrome in the finest detail of the picture. The saving of frequencies resulting from the use of this technique is obtained at a cost in terms of the adverse impact on picture quality, but as indicated below, the overall result meets minimum standards of acceptability." Studio experience in television color program production indicates that lighting will be simplified over what it has been heretofore. Lower color temperatures will be needed — 2900 to 3200 K is expected to be standard. This means that color television can use standard tungsten light sources and will not require the radical changes in studio lighting which were necessary when Technicolor, for example, entered the motionpicture studio. Levels will, of course, be considerably above those required for black-and-white television. "Electronic Photography" in Color and Black-andWhite on Magnetic Tape Recording of television pictures on magnetic tape in color and black-andwhite was demonstrated by RCA on December 1, 1953. 97 Thin, half-inch wide, magnetic-coated plastic tape, running at 30 ft/sec, was used for the color demonstration. Seventeen-inch diameter reels recorded 4 min of television program. Five parallel recordings were made on the single tape, one for each of the red, green and blue primary color signals, the fourth for the synchronizing signal and the fifth for sound. A J-in. wide tape is sufficient for black-and-white recording. Daily: Progress Committee Report 355