These are not used by commercial C-41 processors, and are marketed for home or field use. There are simplified versions of the process that use a combined bleach-fix ( EDTA) that dissolves the silver generated by development and removes undeveloped silver halide. This is followed by a wash, and a final stabilizer and rinse to complete the process. After the bleach, a fixer removes the silver halide. Incorrect temperature can result in severe color shifts or significant under- or overdevelopment of the film.Īfter the developer, a bleach converts the metallic silver generated by development to silver halide, which is soluble in fixer. The control of temperature and agitation of the film in the developer is critical in obtaining consistent, accurate results. As the silver is developing, oxidized developer reacts with the dye couplers, resulting in formation of dyes. The developer develops the silver in the emulsion layers. The developing ingredient is a paraphenylene diamine-based chemical known as CD-4. The C-41 process is the same for all C-41 films, although different manufacturers' processing chemistries vary slightly.Īfter exposure, the film is developed in a "color developer". These couplers, located in the blue, green and red-sensitive layers, produce yellow, magenta and cyan dyes, respectively, when developed. There also may be layers to space different emulsions, or additional filter layers.Įach emulsion layer, in addition to the light-sensitive components, contains chemicals called dye couplers. Some films are top-coated with UV blocking layers or anti-scratch coatings. In addition to multiple emulsion layers, real films have other layers that are not sensitive to light. Each of these layers has different speed and contrast characteristics, allowing the film to be correctly exposed over a wider range of lighting conditions. Almost all C-41 films contain multiple layers sensitive to each color. The illustrative example outlined above differs from the design of actual film, in respect to the number of layers. Beneath the blue-sensitive layer and the yellow filter are the green and red sensitive layers. This filter layer serves to remove the blue light, which would expose the layers beneath it. All silver-based photographic emulsions have some sensitivity to blue light, regardless of what other colors they may be sensitized for. Beneath the blue layer is a yellow filter, composed of dyes or colloidal silver. In the classic illustrative example, there are three emulsions: one is red sensitive, another is green sensitive, and the top is blue-sensitive. Each layer is only sensitive to a certain color of visible light. Note the antihalation layer.Ĭ-41 film consists of an acetate or polyester film base, onto which multiple emulsions are coated. This diagram illustrates the layers FujiFilm has chosen for this film.
FujiColor Superia is an example of a C-41 process film.
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