Contrast (C) describes the
difference in appearance of two parts of a visual field seen simultaneously or
where Lt = luminance of the
= luminance of the background, cd/m2
3.2 Contrast Rendering
Contrast Rendering Factor
(CRF) is the ratio of the detectable contrast in a task under a given lighting system (C1) to that under fully diffused reference lighting (C2).
The reference lighting
conditions are completely diffuse and unpolarized illumination from a photometric
integrating sphere where light comes equally from all direction.