Basics of illumination and Laws of illumination
Basics of illumination and Laws of illumination Introduction: Light is a Electromagnetic radiation Which has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be seen by the normal human eye. what is light? It is the part of radiant energy from a hot body which produce the visual sensation on human eye. Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that is perceived by the human eye. Luminous flux: it is the light energy radiated out per second from the lamp. Its unit is lumen. Lumen : it is defined as the luminous flux emitted in a unit solid angle by a source of one candle power. i. e. Lumen=candle power x solid angle= cp x ω. Luminous intensity (I) or Candle- power: Luminous intensity (I) or Candlepower of a point source in a given direction is the luminous flux (number of lumens) radiated o...