Luminance is the scientific term for “Photopic Brightness” which specifies the visual brightness of an object. In layman’s terms, it is commonly referred to as “brightness”. Luminance is specified in candelas per square meter (Cd/m2) or nits. In the US, the British unit Foot-lamberts (fL) is also frequently used. To convert from fL to nits, multiply the number in fL by 3.426 (i.e. 1 fL = 3.426 nits).

Luminance is an influential factor of perceived picture quality in an LCD. The importance of luminance is enhanced by the fact that humans will react more positively to a brightly illuminated screen. In indoor environments, a standard active-matrix LCD with a screen luminance of around 250 nits will look good. In the same scenario an LCD with a luminance of 1,000 nits or more will look utterly captivating.