Joly, John

SUBJECT AREA: Photography, film and optics

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b. 1857 Holywood, King's County (now County Down, Northwern Ireland), Ireland

d. 8 December 1933 Dublin, Eire

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Irish pioneer of additive screen-plate colour photography.

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Professor of Physics at Trinity College, Dublin, Joly developed a concept first suggested by Ducos du Hauron, creating in 1893 a process in which fine transparent red, green and blue lines, less than 0.1 mm wide, were ruled on a glass plate. The coloured inks were aniline dyes mixed with gum. This screen plate was held in close contact with a photographic negative plate which was exposed through the screen in a camera. The processed negative was printed onto a positive plate, and a viewing screen, similar to that used for taking, was bound up with it in careful register, to reproduce the original colours. The process was patented in 1894, and marketed in 1895. It was the first commercially successful additive screen-plate process to appear. While the results could be quite acceptable, the inadequate colour sensitivity of the negative plates then available limited the usefulness of this process. Professor Joly's other achievements included geological research and the treatment of cancer by radium.

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Further Reading

J.S.Friedman, 1944, History of Colour Photography, Boston.

B.Coe, 1978, Colour Photography: The First Hundred Years, London. G.Koshofer, 1981, Farbfotografie, Vol. I, Munich.

BC