The art of sound pictures (1930)

COLOR 253’ color and Multicolor processes as examples, since they represent the latest developments in this type of color reproduction. Technicolor The Technicolor camera, in which a single lens is used, is specially built for color work. Behind the lens is a group of prisms put together in such a way that two separate pictures are thrown on two successive frames of the same film, A revolving color filter is so arranged that these two pictures, a red picture and a green picture, are photographed simultaneously. When the entire series of picture sequences has been recorded, the film is developed, and this represents the negative carrying latent red and green color values on alternate picture frames. The negatives are now printed on two independent strips of positive film. That is, all the red color values are printed on one strip of film, and the green values on a second strip. These are developed and fixed in the usual way. The two positives are now subjected to a chemical treatment which converts the silver images into what is termed a ‘‘mordanted image.” A mordanted image is one which has the property of absorbing certain dyes. Thus, a positive having the red records is dyed green, and the green records are dyed red. When the films are dyed in their primary colors, both sets of colored pictures are transferred to the same side of a new film. In this process, a fresh film, covered with appropriate gelatine preparation, is pressed successively against the dyed films. The gelatine on the fresh film absorbs the dye from the dye film in the same way that a blank newspaper page absorbs the ink from the presses.