Description of a Comprehensive Family of Relative Contrast Sensitivity (RCS) Functions of Luminance to Reflect Differences in Size of Task Detail, Task Eccentricity and Observer Age

Abstract

This article summarizes the analyses of all suitable experimental data containing information about the quantitative characteristics of the relative contrast sensitivity (RCS) function of luminance, a functional relationship which has become central to the evaluation of the effects of lighting parameters upon visual performance. Separate sets of experimental data are used to develop quantitative assessments of the following factors influencing the mathematical parameters describing the RCS function of luminance: (1) the size of task detail (Blackwell-Taylor data of 1969); (2) the extent to which tasks are viewed in locations eccentric to the ocular line of sight (Blackwell-Moldauer data of 1958); and (3) the effect of observer age (Blackwell-Blackwell data of 1971). A generalized mathematical description of the RCS function of luminance is given which permits calculation of a family of functions reflecting differences in one or more of these three factors.