luminous flux per unit of cross-sectional area.
noun, Optics. 1. the luminous flux in lumens emitted per unit solid angle by a light source, measured in candles. noun 1. a measure of the amount of light that a point source radiates in a given direction. It is expressed by the luminous flux leaving the source in that direction per unit of solid […]
[loo-muh-nuh s] /ˈlu mə nəs/ adjective 1. radiating or reflecting light; shining; bright. 2. lighted up or illuminated; well-lighted: the luminous ballroom. 3. brilliant intellectually; enlightened or enlightening, as a writer or a writer’s works: a luminous concept; luminous prose. 4. clear; readily intelligible: a concise, luminous report. /ˈluːmɪnəs/ adjective 1. radiating or reflecting light; […]
noun 1. paint containing a phosphor that emits visible light when irradiated with ultraviolet light.
noun, Navigation. 1. the distance at which a certain light, as that of a lighthouse, is visible in clear weather, disregarding interference from obstructions and from the curvature of the earth and depending on the power of the light.