Sensitometric Evaluation of Reversible Color Film

Two considerations are involved in the sensitometric evaluation of reversible color film; we are interested in determining the gray-scale characteristics of the material, as well as its faithfulness of color rendition. Equations have been derived relating the equivalent densities of the 3 layers to the color densitometer readings. The 3 curves showing equivalent densities as functions of log exposure indicate speeds, contrasts, maximum densities, and color balance of the film. Color rendition problems are investigated using the principles of colorimetry. — The equivalent densities of a reproduction depend upon the spectral sensitivities of the material as well as the spectral characteristics of the light source and color sample; the color of the reproduction, however, depends not only upon the equivalent densities but also upon the spectral characteristics of the dyes and of the projection source. A typical problem is that of the effect of change of contrast upon the color renditions. Unit contrast, although giving lighter reproductions, involves saturation errors which are prohibitive. A contrast of 1.5 is found to more nearly balance the errors of lightness, hue and saturation.

Print ISSN

0097-5834

Published

1946-05

Content type

Original Research

DOI

10.5594/J11833