Autochrome Process
French · Autochrome Lumière 1907–1935
The first practical colour photography was made with dyed potato starch. Millions of microscopic grains, coloured orange, green and violet, spread over a glass plate and acting as a filter mosaic.
Origin
Patented by the Lumière brothers in 1903 and on the market from 1907, the autochrome was the first colour process available to ordinary photographers, and it remained dominant for around thirty years. Albert Kahn financed the Archives de la Planète, an attempt to document the world in colour, which produced some seventy-two thousand autochromes between 1909 and 1931 and is the largest collection of early colour photographs anywhere.
Technique
A glass plate is coated with a layer of potato starch grains dyed orange-red, green and blue-violet, sorted so that no two adjacent grains share a colour, then rolled flat under pressure and the gaps filled with carbon black. A panchromatic silver emulsion goes on top. Light passes through the coloured grains before reaching the emulsion, so each grain records only its own portion of the spectrum. After reversal processing the plate is viewed through the same grain layer, which reconstitutes the colour. Exposures were long — several seconds in good light — and the result is a unique transparency that cannot be printed conventionally.
The palette
Soft, desaturated and pointillist, with a characteristic warm-tending cast. The dyes are not spectrally pure, so colours are approximate rather than accurate, and the visible grain structure gives the image a granular, slightly dreamlike surface that has been compared to Neo-Impressionist painting since the process appeared. Blues and greens tend to be weaker than reds and yellows, and skin renders particularly well, which is why so many autochromes are portraits.
Legacy
Because the plates are unique and were viewed by transmitted light, they were shown in viewers or projected rather than printed, and most surviving examples have never been widely reproduced accurately. Kodachrome and other subtractive films made the additive screen processes obsolete in the 1930s, but the autochrome remains visually unlike anything else in the history of colour photography.
Palette
The colours reconstructed for this artist, with the reasoning behind each.