luminance du fond

CONT: Light produced by an electronic display has to be of adequate intensity, often vaguely described as its ""brightness"". A more scientific term is luminance in candels per square metre (cd/m2). Visual perception of a pattern depends crucially on contrast. This becomes very noticeable when the controls are adjusted on a CRT [cathode-ray tube] display. Characters may become hard to distinguish and may be lost in the background luminance when the controls are wrongly set.
OBS: cd/m2: cd/m[superscript 2]