Abstract
Abstract: :
Purpose: We had shown earlier that viewers prefer to look at art works lit by higher color temperatures than the typical lighting of 3000 K at 200 lux. The preferred illuminant was about 3600 K at 200 lux, but the illuminants we used differed by steps of about 400 K. To refine those findings, observers now continuously adjusted color temperature and repeated the settings at each of four illuminances. We also tested the hypothesis that the preferred illuminant would appear neither warm nor cool. Methods: The observer looked at a "painting" hung on a matte-gray wall lit by overhead banks of lamps whose combined value could be adjusted continuously between 3000 and 4400 K while keeping illuminance constant. This was repeated for paintings varying in subject matter and color. On different sessions the illuminance value was one of 50, 200, 500, or 2000 lux, achieved by wearing goggles with Inconel neutral density filters. Each trial began with the illumination set, randomly, to one of 3000, 3600, or 4400 K; observers adjusted color temperature until they were satisfied they found the "best" illumination for each painting. In a separate study, using the same procedures, observers viewed a white reflectance standard and adjusted the illumination until it appeared neither warm nor cool. Results: The chosen illuminant for viewing paintings was about 3800 K, independent of intensity from 50 to 2000 lux; settings were largely the same across paintings and across eight observers. A different group (N=8) chose approximately 3700 K as neither warm nor cool, independent of intensity. These illuminants are not "achromatic" but correspond to a dominant wavelength of about 580 nm at 35% purity. Conclusions: Illumination in many museums is suboptimal for aesthetic enjoyment. Preferred illuminant isone that is neither warm nor cool, rather than achromatic. We calculate that for the preferred lighting, the small addition to short-wavelength energy should have minimal impact on preservation.
Keywords: scene perception • color vision