Luminous Efficacy

Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source's output, or it can be the total power (electric power, chemical energy, or others) consumed by the source. Which sense of the term is intended must usually be inferred from the context, and is sometimes unclear. The former sense is sometimes called luminous efficacy of radiation, and the latter luminous efficacy of a source.

The luminous efficacy of a source is a measure of the efficiency with which the source provides visible light from electricity. The luminous efficacy of radiation describes how well a given quantity of electromagnetic radiation from a source produces visible light: the ratio of luminous flux to radiant flux. Not all wavelengths of light are equally visible, or equally effective at stimulating human vision, due to the spectral sensitivity of the human eye; radiation in the infrared and ultraviolet parts of the spectrum is useless for illumination. The overall luminous efficacy of a source is the product of how well it converts energy to electromagnetic radiation, and how well the emitted radiation is detected by the human eye.

Read more about Luminous EfficacyEfficacy and Efficiency, Lighting Efficiency, SI Photometry Units

Other articles related to "luminous, efficacy, luminous efficacy":

Light-emitting Diode - Technology - Efficiency and Operational Parameters
... One of the key advantages of LED-based lighting sources is high luminous efficiency ... White LEDs quickly matched and overtook the efficacy of standard incandescent lighting systems ... In 2002, Lumileds made five-watt LEDs available with a luminous efficacy of 18–22 lumens per watt (lm/W) ...
Growroom - Luminous Efficacy
... High Intensity discharge lamps (HID) have the most efficacy in terms of Lumen (unit)s of light output vs ...
Compact Fluorescent Lamp - Comparison With Incandescent Lamps - Energy Efficiency
... For more details on this topic, see Luminous efficacy ... The luminous efficacy of lamps is the number of lumens produced for each watt of electrical power used ... The luminous efficacy of a typical CFL is 50–70 lumens per watt (lm/W) and that of a typical incandescent lamp is 10–17 lm/W ...
Fluorescent Lamp - Advantages - Luminous Efficacy
... See the table in the luminous efficacy article ... The efficacy of fluorescent tubes ranges from about 16 lumens per watt for a 4 watt tube with an ordinary ballast to over 100 lumens per watt with a modern electronic ... tube, a high-frequency electronic ballast gives about a 10% efficacy improvement over an inductive ballast ...
Luminous Efficacy - SI Photometry Units
... SI photometry units v t e Quantity Symbol SI unit Symbol Dimension Notes Luminous energy Qv lumen second lm⋅s T⋅J units are sometimes called talbots ...

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