ASSESSING UNIFORMITY OF ILLUMINANCE BASED ON A LED TUNABLE SYSTEM

Two psychophysical experiments were conducted to study illuminance uniformity on a desk top. The data were used to evaluate three uniformity metrics. Three attributes were scaled: uniformity, comfort and brightness perceptions using a categorical judgment method. Observers were asked to rate the attributes under different degree of illuminance uniformity in two separate experiments. The results showed that using the ratio between minimum and average to evaluate the uniformity performed the best. The visual results showed that a more uniform light will be felt more comfortable. At a lower illuminance level, a higher uniformity is required to achieve same level of comfort than that at a higher level.