The Luminance-Difference Threshold in Viewing Projected Pictures
E. J. Breneman · Journal of the SMPTE · 1960
The luminance-difference threshold has been determined as a function of luminance for viewing conditions similar to those recommended by the ASA for the projection of professional motion pictures. A stimulus subtending an angle of 0.5° was superimposed briefly upon various areas within typical photographic reproductions. The effective presentation time for each stimulus was about 1 second, which is near the maximum fixation time commonly occurring in the viewing of scenes and pictures. The mean luminance-difference threshold for relatively bright areas within the test scenes was found to be equivalent to a density difference of 0.015. The results indicate the nature of the dependence of the luminance-difference threshold upon the luminance of the test area and upon the luminance of surrounding areas.