Unit of luminous intensity
SI unit (symbol cd) of luminous intensity, which replaced the old units of candle and standard candle. It measures the brightness of a light itself rather than the amount of light falling on an object, which is called illuminance and measured in lux.
One candela is defined as the luminous intensity in a given direction of a source that emits monochromatic radiation of frequency 540 x 10-12 Hz and whose radiant energy in that direction is 1/683 watt per steradian. + prikaži više