Color Photography makes life colorful and enjoyable
British mathematician and physicist James Clerk Maxwell (1931-1879) was a giant of nineteenth century science. Best known for his Maxwell equations which were the best insights 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 short 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.
Creating colors by mixing colored lights (usually red, green and blue) in various proportions is the additive method of color reproduction. LCD, LED, plasma and CRT (picture tube) color video displays all use this method. If one of these displays is examined with a sufficiently strong magnifier, it will be seen that each pixel is actually composed of red, green and blue sub-pixels which blend at normal viewing distances, reproducing a wide range of colors as well as white and shades of gray. This is also known as the RGB color model.