An Infrared Traveling Matte System with Electronic Masking

Abstract

A new, single-film infrared traveling matte system for combining background and foreground scenes, based on the mixed utilization of motion-picture and television technology, has been developed at Lenfilm Studios, Leningrad, U.S.S.R. The infrared electronic traveling matte system employs a special-purpose film which combines color emulsion layers with a black-and-white Infrared-sensitive bottom layer. Photography of the live foreground action is carried out with a standard motion-picture camera against an infrared-radiating background. After exposure, the film is developed for a short period of time in a fast-acting surface developer, as a result of which a transparent silhouette of the foreground action is formed in the infrared-sensitive layer against a dark background or, in other words, a negative “female” matte. The image in the other color-forming layers remains in its latent form. Next, the printing of the background is effectuated by means of a narrow, electronically controlled beam of white light which scans line by line the surface of the background positive in contact with the camera film, exposing the background only in those areas not occupied by the pre-exposed foreground action. Afterwards the film is processed in a regular color negative developer, in the course of which the female matte, composed of metallic silver, is disintegrated in the bleaching step together with the metallic silver images in the color layers. Dimensional mismatch between the matte and the components of the final composite image is thus avoided.