In colour negative films, there are 3 types of dye couplers.

Dye coupler technology has seen considerable advancement since the beginning of modern color photography.

In color slide film, the dye couplers attach to the non-exposed areas.

Chromogenic materials use dye couplers to form colour images.

Each of these dye coupler types react with one of the color layers in the film.

In ordinary print film, the dye couplers attach to particles that have been exposed.

Colour films and papers usually have multiple layers of emulsion, with dye couplers added.

These were the first commercially available color prints created by the chromogenic dye coupler method.

The Kodachrome films contained no color dye couplers; these were added during processing.

The film is then treated with three different dye developers containing dye couplers.

Underneath each color layer, there is a developer layer containing dye couplers.

This film had the dye couplers incorporated into the emulsion, making processing simpler than for Kodachrome.

Each emulsion layer, in addition to the light-sensitive components, contain chemicals called dye couplers.

The fogged silver halides are developed and exhausted developing agents couple with the dye couplers in each layer.

Chloroacetone is used to make dye couplers for colour photography, and is an intermediate in chemical manufacturing.

It was a three-color dye coupler process that produced full-color images in a single photographic emulsion.

Dye coupler is present in chromogenic film and paper used in photography, primarily color photography.

As the silver is developing, oxidized developer reacts with the dye couplers, resulting in formation of dyes.

In concert with the dye couplers in each layer, the process subsequently forms dyes only in those areas where silver is present.

This is the chromogenic reaction-the union of the oxidized developer and the dye coupler form a color dye.

Chromogenic processes yield organic dyes that are less stable than silver, and can also leave unreacted dye couplers behind during developing.

Unlike substantive transparency and negative color films, Kodachrome films did not incorporate dye couplers into the emulsion layers.

The colour developer develops the silver negative image, and byproducts activate the dye couplers to form the colour dyes in each emulsion layer.

Different dye couplers are used in each of three layers, so this same reaction forms a different colored dye in each layer.

Some colour photographic processes also use a weak solution of hydrazine as a stabilizing wash, as it scavenges dye coupler and unreacted silver halides.