Color coupler

In analog photography, color couplers are colorless substances or substances provided with azo dye compounds that produce the three basic colors in photographic multilayer films after subtractive color mixing ( color coupler reaction ); it is a chromogenic process .

During chromogenic development, the color couplers, together with the oxidation products of the developer and the silver bromide, form water-insoluble, diffusion-resistant dyes.

In addition to color films, chromogenic black and white films can also have color couplers which produce a black and white dye image during development.

Most of the color couplers have been patented for the respective manufacturers ; the Fuji Fujichrome Velvia , for example, has three patented couplers, the so-called X, V and S couplers.

See also

• Color photography
• Film development
• DIR coupler ( Developer Inhibitor Releasing Coupler ), a colorless color coupler in films based on the Eastman Color process

Films:

• Kodak Kodachrome - here the color couplers are not incorporated into the film layer, but are only introduced during processing with the color developers .

Web links

• The chromogenic development on the homepage of Prof. Blume