Neutral Color Balance of Films for Color Television

Abstract

Proposals have been made to international standardizing groups that the color balance of films for television be defined as that balance which produces in the film a metameric match of a gray object in the scene. This criterion has been questioned on the basis that photographic experience leads to the conclusion that a color balance based on exact neutral reproduction does not result in the most pleasing picture. — We have tested this assumption by an experiment in which observers determined the most pleasing Eastman Color print of several scenes from a variety of prints of differing color balance using the paired-comparison viewing method. The neutral balance of each scene, determined from a separate but correlated picture, was compared with the color of the original neutral object. When the prints were viewed with 3600-K projection light, the neutral balance corresponding to the preferred print was colder (more cyan) than the original neutral object. However, when the prints were viewed at 5700 K, with and without ambient light of the same color, the most pleasing picture was obtained when the picture neutral was a metameric match with the object neutral. — We conclude, therefore, that for the Eastman Color system, a metameric gray scale match can be used as a basis for color balance specification.