Tuesday, January 19, 2010

Eigengrau

From http://en.wikipedia.org/wiki/Eigengrau

Eigengrau (German: "intrinsic gray"), also called Eigenlicht
("intrinsic light"), dark light, or brain gray, is the color seen by
the eye in perfect darkness. Even in the absence of light, some action
potentials are still sent along the optic nerve, causing the sensation
of a uniform dark gray color.

Eigengrau is perceived as lighter than a black object in normal
lighting conditions, because contrast is more important to the visual
system than absolute brightness. For example, the night sky looks
darker than eigengrau because of the contrast provided by the stars.