Cross-cultural preferences for optimal daylight illumination in viewing human faces

Lighting conditions influence the perception of health, well-being, and human interaction when viewing faces. This study aimed to determine the preferred daylight illumination to perceive human faces, considering cross-cultural influences. Hyperspectral data from 11 human faces were used to simulate on a computer screen the effects of 41 CIE D illuminants with correlated color temperatures (CCTs) from 4000 to 25,000 K. The observers' task was to select the preferred image of the faces rendered under the illuminants. Images represented faces of male and female individuals of both dark and light skin tones. Among the 41 illuminants available, the most frequently selected as preferred by European participants was 5063 K, by African participants was 5756 K, and by Asian participants was 5836 K. Significant differences were found between the European group and the other groups. These findings have implications for lighting design in multicultural environments.