In motion pictures, Kodak's Kodacolor brand was associated with an early lenticular (additive color) film system, first introduced in 1928 for 16mm film.[1] The process was based on the Keller-Dorian system of lenticular color photography.
The process used a special panchromatic black-and-white film stock used with the emulsion away from the lens.[2] The film base in front of the emulsion was embossed with a mass of tiny lenses, the purpose of which was to form small images of a striped filter which was attached to the camera lens. The filter had three coloured stripes (red, green and blue-violet); when an exposure was made the varying proportion of each colour reflected from the subject passed through the filter and was recorded on the film beneath each of the embossed lenses as areas of strips in groups of three, each strip varying in density according to the received colour value (Dufaycolor used similar principles, but had the filter as part of the film itself).
Filming required the camera to be used at f/1.9 only, so that the striped filter worked correctly. The original Kodacolor film required an exposure of about a 1/30 second at f/1.9 in bright sunlight representing a film speed in modern terms of about 0.5 ISO. The later Super Sensitive Kodacolor could be used "outdoors in any good photographic light, and even indoors under favourable conditions."
To project the film a projector was required fitted with the Kodacolor Projection Filter, which is similar in appearance the filter fitted to the camera. The lenticular image on the film is transformed into a natural colour picture on the screen. As with most colour processes involving a lenticular image the pattern intrudes, and there is noticeable light loss.
While Kodacolor was a popular color home-movie format, it had several drawbacks. It could not yield multiple copies easily, special film was necessary to shoot with, and the additive image was colorful and clear, but inherently darker than subtractive processes. The process was discontinued in 1935 with the introduction of Kodachrome.