The E-3 process is a now outdated process for developing color reversal (transparency)

Transparency (photography)

In photography, a reversal film is a type of photographic film that produces a positive image on a transparent base. Also known as dias or slide. The film is processed to produce transparencies or diapositives instead of negatives and prints...

 photographic film, which was invented in the early 1950s.

The E-3 process was run at near room temperature (24°C/75°F) and requires a manual reexposure of the film in order to affect color development. Often, still photographers would accomplish this by use of a strobe unit in the darkroom. The process took approximately one hour.

Films designed for E-3 are prone to fading because of inferior color dyes. The process was phased out in 1974 in favor of E-4

E-4 process

The E-4 process is a now outdated process for developing color reversal photographic film.The process is infamous for its use of the highly toxic reversal agent Tertiary Butyl-Amine Borane . The use of the reversal agent permits processing of the film without the manual reexposure that its...

, and two years later E-6

E-6 process

The E-6 process is a chromogenic photographic process for developing Ektachrome, Fujichrome and other color reversal photographic film....

was introduced which remains in use to this day.

External links

• Kodak specifications for hand mixing of chemistry

Processing of older Ektachrome films including Process E-3 :

• Process C-22 UK and Europe
• Film Rescue USA and Canada
• Rocky Mountain USA