British mathematician and physicist James" Clerk Maxwell (1831-1879) was a giant of nineteenth- century science. Best known for his Maxwell equations, which were the best insight into electromagnetism of their day, his interests also included Saturn's rings and the human perception of color. It was this latter interest that led to the first color photograph in 1861.
In the manner of a true showman, Maxwell revealed his photograph of a tartan ribbon at the Royal Institution in London. His studies of human vision, including the condition of color blindness, had led him to conclude that color images were possible using a "trichromatic process." He had arranged for his tartan ribbon to be shot by professional photographer Thomas Sutton, the inventor of the single-lens reflex camera. The images were black and white, but, critically, Maxwell had three such images taken through red, green, and blue filters, respectively. Having turned the images into slides, he then projected them through the same filters in such a way that they were carefully superimposed on each other on the screen. The effect was a recognizable reproduction of the tartan in glorious color.
Maxwell was lucky. His demonstration should not really have worked at all because, unknown to him, his photographic emulsion was not sensitive to red light. Fortunately, the red in the tartan did reflect ultraviolet light, and this was picked up by the emulsion.
The trichromatic process became the foundation for all color photography, and Maxwell's three original slides of the tartan ribbon are now on display in a small museum in Edinburgh.
