“In a lecture on the theory of three primary colors, given at the Royal Institution of Great Britain on May 17, 1861, Maxwell presented the first demonstration of a photograph in color. According to the records of that meeting (Maxwell, 1890c, p. 449), Maxwell first discussed Young’s theory of vision (Young, 1845, pp. 344-345; Helmholtz, 1924, pp. 142-146) and the principles involved in making color mixtures. He then illustrated these methods by placing three positive photographic transparencies in different projectors with red, green, and blue filters in their respective light paths, and registering the projected images on a screen. As a photograph, the result was not particularly good, but the principle involved was essentially sound. These same principles actually had been enunciated by Maxwell as early as 1855 (Maxwell, 1890b, pp. 136-137).
The photograph demonstrated by Maxwell was prepared by Thomas Sutton, a well-known photographer of that time. Sutton’s description of his work (Sutton, 1861) conflicts in some details with other reports of the Maxwell demonstration. He stated that four photographic transparencies were made and projected, a yellow filter being used in addition to the red, green, and blue ones. The two versions of what took place cannot be reconciled, but it is certain that Maxwell clearly understood that analysis and synthesis by three, and only three, basic colors were required.
Sutton found it difficult to obtain a photographic result with the red and yellow filters and, to an even greater extent, the green filter. The filter solutions finally used were so dilute and the exposure times so long that it is quite likely that only radiations from the ultraviolet and blue regions of the spectrum were effective in each case. The lack of sensitivity in the green and red spectral regions was characteristic of all the photographic materials available at that time and, for the major part at least, accounts for the poor quality of Maxwell’s results. It is possible that much of the color seen was of the subjective type due to adaptations similar to those which make two-color photography appear more satisfactory than colorimetric theory would suggest (see Evans, 1943).
The blue, green, and red filters used for the Maxwell photograph were obtained with solutions of copper ammonium sulfate, cupric chloride, and ferric thiocyanate, respectively. The same solutions were used in making the exposures as in projecting the final picture. As later indicated by Ives, and in accordance with present established theories of color reproduction in additive color photography (see pp. 621-622), the absorption distributions of the taking and viewing filters should, in general, be quite different from each other. Maxwell’s procedure did not, therefore, conform to what we now know to be the theoretical requirements. In fact, we may say that Maxwell’s ideas were accepted in spite of, rather than because of, his demonstration. His talk crystallized the possibility of three-color photography.”
(Evans, Ralph Merrill / Hanson, W.T., Jr. / Brewer, W. Lyle (1953): Principles of Color Photography. New York: Wiley 1953, pp. 271-272.)
Original Technical Papers and Primary Sources
Clerk Maxwell, James (1855): Experiments on Colour. In: Transactions of the Royal Society Edinburgh, Vol. XXI., part II, pp. 283-284.
Clerk Maxwell, James (1860): On the Theory of Compound Colours. In: Philosophical Transactions of the Royal Society, No. 150.
Clerk Maxwell, James (1861): British Journal Photography, 1861, 8, 272.
Evans, Ralph Merrill / Hanson, W.T., Jr. / Brewer, W. Lyle (1953): Principles of Color Photography. New York: Wiley 1953, pp. 271-272.