I recently came across a collection of the first colour photographs of Paris (taken from 1907 to 1930). They are well worth a look. Here are the details of how the potato helped take these colour photographs:
As surprising as this may seem, there are many photographs of Paris shot in direct color from 1907 to 1930.
The Autochrome process was developed by the Lumière brothers in 1903. The technique was based on a composite of black and white emulsions passed through a series of color filters (red, blue and green) designed based on potato starch.The presence of these filters reduced the sensitivity of the emulsion, where the length of the pause time and difficulty required to capture movement. The first shots were carried out in Morocco in 1907. The process was a such a hit such that the Lumière factories produced up to 6000 plates per day! This technique was abandoned in 1935 in favor of the process Kodachrome, then Agfachrome the following year. The banker Albert Kahn, who wished to leave an imprint of the period, sent photographers across five continents to create the “Archives of the Planet”. Its foundation is now a base of approximately 72,000 Autochromes. The images published on this site are among others the work of Leon Gimpel, Stephane Passet, Georges Chevalier and Auguste Leon. They offer an unexpected proximity with this century that imagination restores in black and white. This site is a collection of Autochrome made in Paris between 1914 and 1918. Lovers will find all additional information on the Albert Kahn Museum website, which own the rights of some of these images.–