The coming of colour.
Colour as a science began in 1666, when Isaac Newton discovered the solar spectrum and that colours are present in all light. By the mid-nineteenth century the basic principles of the colour theory were established. The first true colour photograph was made by Scottish scientist, James Clerk-Maxwell in 1861. It involved three black and white photographs, each taken through a red, green, or blue filter. Three projectors were then aligned so that the images reached a screen in register providing a recognizable colour picture of a tartan ribbon. This is the basis of “colour separation”. Following experiments by many able individuals, it was not until 1936 that Kodak and Agfa almost simultaneously produced a system practical enough to market. They both launched reversal colour film for 35 mm still cameras. These Kodak and Agfa tripacks were extremely slow, but throughout the 1940s film speeds increased. These slide films however did not wholly fill the needs of amateur photographers. They wanted colour prints. These followed in the 1950s. Since then chemists have made huge progress and today we have colour films giving superb saturation and sharpness even with fast films.