In 1862, Louis Ducos du Hauron began development of a camera and photographic process designed to record full colour images. Six years later he suggested subtractive colour synthesis and patented a three-image process requiring the use of different filters and coloured papers. Charles Cox, a poet, also proposed his own separately developed additive process which superimposed orange, green and blue negatives to produce full colour.
Neither of these methods proved practical nor found commercial success, but they nevertheless formed the basis of the Lumiere brother's work at the beginning of the twentieth century. Auguste and Louis Lumière were pioneers in the public projection of moving images. At their factory in Lyons in France they devised a varnished glass screen, coated on one side with tiny randomly-scattered particles of starch dyed in the three primary colours. A layer of panchromatic emulsion was applied to the reverse. Exposures were of a few seconds in good light and the plates were processed to give a positive colour image. This became known as the "autochrome" process, and was made available in 1907.
In 1912 chromogenic development, the conversion of latent silver images directly to colour, was proposed. Kodachrome, the first commercial three-layer colour film based on this principle, became available in 1935.