Columbia colour

SUBJECT AREA: Broadcasting, Electronics and information technology, Recording

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After education in Hungary and a period as an assistant at the Technische Hochschule, Berlin, Goldmark moved to England, where he joined Pye of Cambridge and worked on an experimental thirty-line television system using a cathode ray tube (CRT) for the display. In 1936 he moved to the USA to work at Columbia Broadcasting Laboratories. There, with monochrome television based on the CRT virtually a practical proposition, he devoted his efforts to finding a way of producing colour TV images: in 1940 he gave his first demonstration of a working system. There then followed a series of experimental field-sequential colour TV systems based on segmented red, green and blue colour wheels and drums, where the problem was to find an acceptable compromise between bandwidth, resolution, colour flicker and colour-image breakup. Eventually he arrived at a system using a colour wheel in combination with a CRT containing a panchromatic phosphor screen, with a scanned raster of 405 lines and a primary colour rate of 144 fields per second. Despite the fact that the receivers were bulky, gave relatively poor, dim pictures and used standards totally incompatible with the existing 525-line, sixty fields per second interlaced monochrome (black and white) system, in 1950 the Federal Communications Commission (FCC), anxious to encourage postwar revival of the industry, authorized the system for public broadcasting. Within eighteen months, however, bowing to pressure from the remainder of the industry, which had formed its own National Television Systems Committee (NTSC) to develop a much more satisfactory, fully compatible system based on the RCA three-gun shadowmask CRT, the FCC withdrew its approval.

While all this was going on, Goldmark had also been working on ideas for overcoming the poor reproduction, noise quality, short playing-time (about four minutes) and limited robustness and life of the long-established 78 rpm 12 in. (30 cm) diameter shellac gramophone record. The recent availability of a new, more robust, plastic material, vinyl, which had a lower surface noise, enabled him in 1948 to reduce the groove width some three times to 0.003 in. (0.0762 mm), use a more lightly loaded synthetic sapphire stylus and crystal transducer with improved performance, and reduce the turntable speed to 33 1/3 rpm, to give thirty minutes of high-quality music per side. This successful development soon led to the availability of stereophonic recordings, based on the ideas of Alan Blumlein at EMI in the 1930s.

In 1950 Goldmark became a vice-president of CBS, but he still found time to develop a scan conversion system for relaying television pictures to Earth from the Lunar Orbiter spacecraft. He also almost brought to the market a domestic electronic video recorder (EVR) system based on the thermal distortion of plastic film by separate luminance and coded colour signals, but this was overtaken by the video cassette recorder (VCR) system, which uses magnetic tape.

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See also: Baird, John Logie

SUBJECT AREA: Photography, film and optics

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Both from distinguished musical families, Godowsky and Leopold Damrosch Mannes met at Riverdale School in New York in 1916, and shared an interest in photography. They began experiments in methods of additive colour photography, gaining a patent for a three-colour projector. Godowsky went to the University of California to study chemistry, physics and mathematics, while working as a professional violinist; Mannes, a pianist, went to Harvard to study music and physics. They kept in touch, and after graduating they joined up in New York, working as musicians and experimenting in colour photography in their spare time.

Initially working in kitchens and bathrooms, they succeeded in creating a two-layer colour photographic plate, with emulsions separately sensitized to parts of the spectrum, and patented the process. This achievement was all the greater since they were unable to make the emulsions themselves and had to resort to buying commercial photographic plates so that they could scrape off the emulsions, remelt them and coat their experimental materials. In 1922 their work came to the attention of C.E.K. Mees, the leading photographic scientist and Director of the Eastman Kodak Research Laboratory in Rochester, New York. Mees arranged for plates to be coated to their specifications. With a grant from Kuhn, Loeb \& Co. they were able to rent laboratory space. Learning of Rudolf Fischer's early work on dye couplers, they worked to develop a new process incorporating them. Mees saw that their work, however promising, would not develop in an amateur laboratory, and in 1930 he invited them to join the Kodak Research Laboratory, where they arrived on 15 June 1931. Their new colleagues worked on ways of coating multi-layer film, while Mannes and Godowsky worked out a method of separately processing the individual layers in the exposed film. The result was Kodachrome film, the first of the modern integral tripack films, launched on 15 April 1935.

They remained with Eastman Kodak until December 1939; their work contributed to the later appearance of Ektachrome colour-reversal film and the Kodacolor and Eastman Color negative-positive colour processes. Mannes became the Director of his father's Music Academy in New York, remaining as such until his death in 1964. Godowsky returned to Westport, Connecticut, and continued to study mathematics at Columbia University. He carried out photographic research un his private laboratory up until the time of his death in 1983.

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