Though the invention of photography had an immediate impact on the whole art world, the early photographs were in monochrome. As an additional service, daguerreotypes could be hand- painted, which kept a number of painters of miniatures in business. However, it was to be some time before colour photography was to become a reality.
In the 1860s James Clerk Maxwell, using as a subject a tartan ribbon, showed that three monochrome images could be formed of a subject, each one taken using a different colour filter (red, blue and green). By projecting these images using three lanterns, each equipped with a corresponding filter, the colours could be recreated.
The results were somewhat disappointing to Maxwell and his collaborator Thomas Sutton, but nevertheless they deserve the credit for laying the foundations of trichromate colour photography.
Interestingly, strictly speaking this experiment should never have worked! Maxwell did not know this, but at that time the emulsion in use only responded to light at the blue end of the spectrum. So how could anything have been recorded on the "red" and "green" slides? It was not until one hundred years later that when the experiment was repeated, it was discovered that the green filter had also passed some blue light, whilst the ribbon's red colours were also reflecting ultra-violet rays, which had been recorded on the red plate. However, though this (by sheer coincidence) produced the right effect, it does not detract from Maxwell's discovery, for with an appropriate emulsion responding to all colours the method works well.
In 1873 Herman Vogel discovered sensitising dyes, which was a step forward in the pursuit of full colour photography. As a result of his work, "orthochromatic" plates, sensitive to all colours with the exception of red, were produced.
When in 1906 "panchromatic" films, sensitive to all colours, came into production, some photographers began taking three "separation" negatives, using a viewer which enabled one to see all three slides superimposed upon one another.
In 1907 Auguste and Louis Lumière produced plates they called Autochrome, using a different system from that above. The colours appeared in delicate pastel shades, often looking very dark, but were well received at the time.
Back in 1869 Ducas du Hauron had published a book offering another method - the subtractive one - by which colour could be re-created. One of his suggestions had been that instead of mixing colour lights, one could combine dyed images; film could be coated with three very thin layers of emulsion, each sensitive to the primary colours; once processed as positives, the transparency could then be viewed as a full colour photograph. At the time, however, the emulsions were such that none of his proposals could be tested. It was not until the mid 1930s that Kodak was to produce a film based on this principle, to be named Kodachrome; up till then the additive methods suggested by Maxwell had been used.
© Robert Leggat, 1999.