Abstract

Using gratings with various areas (A) and spatial frequencies (f < 4 c/deg, where the attenuating effect of the transfer function of eye optics is negligible) we measured Michelson contrast sensitivity as a function of retinal illuminance (l). At high luminance levels contrast sensitivity (S) was independent of retinal illuminance obeying Weber’s law, whereas at low luminance levels S = k × l^–0.5 obeying the DeVries-Rose law.

© 1991 Optical Society of America