Color transparency film forms dyes according to a reversed silver positive; for example, a yellow dye image forms in the top emulsion that corresponds to an absence of blue in the original scene. This yellow dye subtracts blue light. A blue image is formed by magenta dye (minus green) and cyan dye (minus red), thus leaving blue. In color transparency film, the dyes subtractively produce a correct color positive image of the scene photographed.

The Kodak E-6 Process is used in the Navy for processing color reversal film. There are seven chemical steps and two wash cycles in the Kodak E-6 Process. They are as follows: first developer, wash, reversal bath, color developer, prebleach, bleach, fixer, wash, and final rinse.

The first chemical step is the first developer. The first developer is a black-and-white developer that converts the exposed latent image in each emulsion layer to a metallic silver. Like black-and-white negative processing, after the film leaves the first developer, there are undeveloped areas where the silver halides are unaffected by camera exposure. It is these undeveloped areas that the final color positive images are formed in reversal film.

After the first developer, the film is chemically fogged or re-exposed in the reversal bath. The reversal bath exposes the silver halides that were not developed in the first developer. This re-exposure is what forms the positive image. After 1 minute in the reversal bath, the normal room lights can be turned on.

After fogging, the film is developed in a color developer. The color developer works the same way in color reversal processing as it does in color negative processing. It changes the fogged silver halides to black metallic silver and at the same time, cyan, magenta, and yellow dye couplers are formed by the exhausted developer.

At this stage the film looks completely black because the formed dyes are shielded by the developed silver. The film is then placed in a prebleach. The prebleach prepares the film for the bleach and also stabilizes the dye layers.

The metallic silver is removed by the bleach and fixer processes. The bleach and fixer work the same way as they do for color negative processing. After the silver is removed, only the dyes remain, forming the image.

The film is then washed to rinse away any remaining chemistry and soluble silver. The last chemical step in the E-6 process is the final rinse. Final rinse provides a wetting agent to aid in uniform drying.

It is possible to push process (underexpose and overdevelop) or pull process (overexpose and underdevelop) most color reversal film; however, some sacrifice in quality results in "push processing." Less detail in the shadow areas (weaker blacks), less exposure latitude, and noticeably increased grain occur when color reversal film is "push processed." When the film speed is altered, only the first developer time is changed. All other chemical steps remain the same. You should not exceed two f/stops when you intend on push or pull processing.