Luminance range effect on brightness exponent in the fovea and periphery.

Using a method of magnitude estimation, the exponent of the brightness power function has been determined for functions describing the brightness of stimuli presented at the fovea and the following peripheral retinal locations: 10, 20, 30, 40, and 50 degrees nasally eccentric to the fovea along the horizontal meridian of the right eye. The exponent for a 1-sec. flash was significantly increased as a function of increasing eccentricity at the lower luminance ranges whereas slightly increased at the higher luminance ranges.