This week marks the anniversary for the application of a patent by the Lumiere brothers for an early color photography process known as Autochrome. The Lumiere brothers are primarily known for their innovative work in moving pictures, but they quickly became bored with the medium and shifted their focus to the color photography process. While color photographic processes had been possible since 1861, it wasn't until the Lumiere brothers patented their Autochrome process in 1904, and that it was made available to the general population in 1907, that color photography became a commercially viable process. Relegated to scientists' labs and artists' studios until this point, color photography had been relatively inaccessible. Autochrome plates could be easily developed at home in 15 minutes.
The Lumiere Autochrome utilized an additive color process that involved coating a glass plate with potato starch dyed red, green, and blue that acted as color filters. A fine black soot was used to fill up any spaces left between the starch grains. A varnish layer was then applied followed by a gelatin silver emulsion layer. When loaded into a camera, light would pass through the dye filter before reaching the emulsion. Plates were then reversal processed into a positive transparency.
Color photography was available long before the technology for color printing came along in 1941, when Kodak made it possible to order prints from Kodachrome slides. Because printing wasn’t an option, Autochromes were best viewed as projections or with the aid of special equipment, such as a diascope. The Autochrome process was used to produce color photography well into the 1930s, but fell out of use as advances in subtractive color film processing allowed for a wider spectrum of color to be captured.
Check out the Smithsonian Gardens blog, where the role of Autochrome in capturing colorful gardens is explored.