In color vision, the color experience of a given light mixture may vary with absolute luminosity, due to the fact that both rods and cones are active at once in the eye, with each having different color curves, and rods taking over gradually from cones as the brightness of the scene is reduced. This effect leads to a change in color rendition with absolute illumination levels that can be summarised in the Kruithof curve, named after A. A. Kruithof .

References:

• A.A. Kruithof. "Tubular Luminescence Lamps for General Illumination". Philips Technical Review, vol.6, 65-96, 1941.
• Davis, Robert G. and Dolores N. Ginthner. 1990. Correlated color temperature, illuminance level, and the Kruithof curve. Journal of the Illuminating Engineering Society 19(1):27-38.

External links

• The Color of White: Is there a "preferred" color temperature for the exhibition of works of art?
• Daylight: Is it in the eye of the beholder?