Louis Ducos du Havron, French physicist and inventor, c 1900.
© Science Museum / Science & Society Picture Library
Du Havron (1837-1920) invented the trichrome proces, a key invention in the development of early photography. This involved photographing through coloured filters, printing the negatives on coloured gelatin sheets, and superimposing the resulting positives to create a full-colour photograph. Four years earlier, in 1864, he patented a device for taking and projecting motion pictures. His work was described in his books 'Colours in Photography: Solution of the Problem' (1869), and 'Colours in Photography: Colour Reproduction with Carbon Pigments' (1870). In 1891 he also patented the anaglyph, a device for three-dimensional photography. Although he made little money from his inventions, he was made a chevalier of the French Legion of Honour in 1912.