Discomfort Glare from Small, High-Luminance Light Sources When Viewed against a Dark Surround

摘要

This research examined human subjective responses to small, high-luminance light sources against low-luminance backgrounds and evaluated performance of four discomfort glare models. Forty-seven observers evaluated 36 conditions including three glare source luminances (20,000, 205,000, 750,000 cd/m(2)), two source positions (0 degrees, 10 degrees), two source sizes (10(-5), 10(-4) sr), and three background luminances (0.03, 0.3, 1 cd/m(2)) on a seven-point rating scale of perceived glare. The Unified Glare Rating (UGR) small source extension had the highest correlation with subjective responses (r=0.879, P<0.0001) within the ranges of the variables tested. This study validates and extends the UGR small source extension, typically used in interior spaces, to dark surrounds (for example, outdoor nighttime environments).