Modelling glare effects on brightness perception

PABLO BARRIONUEVO; ELISA COLOMBO; LUIS ISSOLIO

Lausanne

Congreso; ECVP 2010. XXXIII Annual Meeting European Conference on Visual Perception; 2010

The brightness of a mesopic test is affected by peripheral glare in transient conditions, when the surround luminance is in the low mesopic or scotopic region. This lost of constancy seems to be caused by the change in excitation from rods to cones led by the increment of retinal illuminance due to glare. We present new complementary results and a model of these brightness variations. Three young subjects evaluated the brightness of a transient foveal test when a peripheral glare (60lx) was simultaneously presented. The stimuli were increments with luminance of test (Lt) and surround (Ls) between 0.01 and 4 cd/m2. The effect of the surround luminance on the results prevailed over the effect of test luminance while the highest effect of the test was obtained when the surround was the minimum. Results were fitted using an exponential function with only two parameters considering Ls as the independent variable. The exponential fit used can model, with enough goodness, besides the effects of surround, the effects of test and adaptation.