Glossary A–ZLetter N
Nits (brightness, cd/m²)
One nit is one candela per square metre (cd/m²) and describes how much light a screen's surface emits.
Data sheets almost always use “nit” for this unit, which measures luminance.
Brightness determines whether a picture can still be seen clearly in its surroundings. A screen in a windowless corridor needs far less than one in a shop window that gets direct sun. There are dedicated high-brightness devices for bright locations; some adjust their brightness to the surroundings using a light sensor.
How well the picture can be seen also depends on ambient light, reflections on the surface and the content itself. More brightness also means more power consumption and more heat. A screen set too bright in a dark room dazzles and is unpleasant to look at. Operators should therefore look at the location before settling on a figure from the data sheet, and adjust brightness according to the time of day.