Additive 3 color: 4 images on 65 mm
Nowotny, Robert A. (1983): The Way of All Flesh Tones. A History of Color Motion Picture Processes, 1895-1929. New York: Garland Pub., pp. 272-273.
Ryan, Roderick T. (1977): A History of Motion Picture Color Technology. London: Focal Press, pp. 46–47 and p. 49.
Thomascolor was a three-color additive system of color cinematography invented by Richard Thomas. Examination of the patents granted to Thomas, 1934–1941 indicates he started his research in an attempt to solve the parallax problem for a two-color system, and from this work evolved a three-color system.30 Although demonstrated successfully several times, the Thomascolor process was never used for feature production.
For original photography the Thomascolor process employed a conventional type 65 mm camera equipped with a special optical system. Four segmented optical units arranged around a common axis and separated by septums were used to produce four color separation negatives within a single frame (Fig. 20). The upper left image was the red record, the upper right image was the green record and the two lower images were the blue record. Thomas states that two images were necessary for the blue record in order to compensate for the sensitivity of panchromatic emulsions to blue and ultraviolet light. By using very dense filters and obtaining two partially exposed violet images, much better color rendition was obtained and the process was more readily controlled. The Wratten 25 filter was suggested for the red record, Wratten 58 filter for the green record and Wratten 47 for the blue records.31 Ordinary black and white panchromatic film was used in the camera. An adjustment of 1 1/2 lens stops was necessary when calculating the correct exposure because of the light loss in the optical system. After exposure, the negative received normal development in a conventional black and white developer. Prints were made on black and white print film by optical reduction to 35 mm. A conventional reduction printer was used.
A disadvantage of the Thomascolor process that possibly had some effect on its lack of acceptance by the motion picture industry was the need for a special optical system in order to project the Thomascolor prints in color. Its use in a production would require every theater that showed the picture to obtain the special Thomascolor optics for both projectors.
30 The Thomascolor two-color system is described briefly in “Report of the Color Committee,” Journal of The Society of Motion Picture Engineers, July, 1931, p. 116.
31 USP 2152224.”
(Ryan, Roderick T. (1977): A History of Motion Picture Color Technology. London: Focal Press, pp. 46–47 and p. 49.)
A two-color additive system invented by an American named Richard Thomas. Plagued with unacceptable parallax problems, Thomas turned to a three-color additive system in 1934. Although several demonstrations of his three-color system proved successful, neither of his color processes was used for feature production.
Additional color processes announced in trade publications, industry journals or film history texts for the period 1928-1932 include: the Busch Process, Dunning Color, Sirius, Wolff-Heide, Herault Process and Talkie-Color. None of these additional color systems reached the theater screen either in the United States or abroad. Somewhat more successful were the French Chimicolor Process and the German Ufacolor Process (called Spectracolor in England), which were both introduced in 1931. Their use, however, was confined to the European continent.”
(Nowotny, Robert A. (1983): The Way of All Flesh Tones. A History of Color Motion Picture Processes, 1895-1929. New York: Garland Pub., pp. 272–273.)
Timeline of Historical Film Colors by Barbara Flueckiger is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.