Abstract

Using circular gratings, where luminance L=Lo [1 + m sin(2πfE + ø)] was modulated as a function of eccentricity E in angular degrees of the visual field, we measured Michelson contrast sensitivity as a function of relative grating size, calculated as Af² and expressed in terms of the number of square cycles. As with linear gratings (e.g., vertical bars and horizontal luminance modulation), the increase of contrast sensitivity with Af² was similar at all spatial frequencies studied and saturated between 100-200 square cycles irrespective of spatial frequency. In addition, contrast sensitivities for a linear and circular grating were similar irrespective of spatial frequency (f) or grating area (A).

© 1991 Optical Society of America