The brightness of a digital display device is measured in?

The brightness of a digital display device is primarily measured in candelas per square meter, which provides a quantifiable measure of luminous intensity per unit area. This measurement indicates how much light is emitted from the display surface in a specific direction, effectively capturing the perceived brightness to the human eye.

Candelas per square meter, often referred to as "nits," actually represent the same measurement but are expressed in different terminology. While "nits" is commonly used in the context of displays like televisions and computer screens, the scientific standard unit is indeed candelas per square meter.

Lux and foot-candles, on the other hand, measure illuminance, which pertains to the amount of light that illuminates a surface rather than the brightness of the light emitted from a source like a digital display. Therefore, while these terms may relate to lighting and visibility, they do not apply directly to how a digital display's brightness is defined and quantified.