Perception lag as a function of stimulus luminance

Abstract Perception lag as a function of stimulus luminance has been measured over the intensity range of about 10–1000 trolands. Three techniques have been used, based on (1) a subjective concurrence of two flashes with different luminance, (2) a subjective concurrence of a flash and a tone pulse, and (3) reaction time to a flash. The results of the three methods are in fair agreement and show a simple logarithmic relationship.