Brightness is the perception of intensity of light. Roughly, the more intense a light is, the brighter it seems to be. Intensity refers to the physical energy of light, as measured by a photometer. Brightness, however, is a perceptual phenomenon: it cannot be measured by physical instruments. It is a basic perception, difficult if not impossible to describe; it must be experienced. Measurements of brightness are generally observers’ reports of their experience viewing lights of different... więcej

Salem Press Encyclopedia of Health, 2023. 4p.