Autochromes Lumière

The Investigations of the Lumière Brothers  (1891 - 1895)

Before the Invention of the Autochrome Plate
In 1895, the Lumière brothers produced their first trichromatic slides on glass. The patent for the invention was entitled Procédé photographique aux mucilages bichromatés donnant sans transfert, des images avec leurs demi-teintes, et application de ce procédé à la photographie des couleurs [Photographic process with bi-chromatic mucilage, produced without transfer, of images with their semi-colouring, and application of the process to colour photography] (French 15-year patent no. 245948, 22nd of March, 1895). The result was surprising and obtained levels of saturation far beyond those that would later be realised in the Autochrome. It prefigured, at a relatively primitive era, results close to modern transparency slides with Chromogenic Chromogenic
The collection of silver-based colour photographic procedures in which the colourants making up the definitive image (yellow, magenta and cyan) are formed by chemical synthesis during development.
photography. This process would be presented under the title ALL Chroma, with the acronym ALL standing for Auguste and Louis Lumière. But the two inventors were never able to sufficiently simplify the operational protocol associated with the procedure. It would however be applied to the edition of stereoscopic views produced in a specially converted workshop at the Monplaisir site. The definitive image was formed by bringing the three coloured elements (yellow, magenta, and cyan) together on a glass support. This technique, which could be described as a hybrid, incorporated the photo-sensitivities of some bichromated colloids (a process of sodium chromate) with the transfer of colourants by Hydrotropy or Imbibition Hydrotropy or Imbibition
The penetration of a liquid composition into a solid body. In photography, the colour procedures called "by imbibition or hydrotropy" produce images by exploiting the affinity of a substance, generally organic (gelatine, amidon, etc), to solidify water-soluble colourants.
. The term "mucilage", borrowed from pharmacology, designates a viscous liquid formed by a watery solution from a colloid (gelatine, gum, etc.).