What is the luminous efficiency of the LED light source?
Any artificial light source has luminous efficiency". It is the ratio of the light emitted by a light source (unit lumen) to the power consumed when it emits light.
LED emits light of 120 lumens and uses 2 watts, then its luminous efficiency is (120/2) 60 lumens / watt.
Luminous efficiency refers to the amount of visible light (380-700nm) from the surface of the LED chip (that is, how much LM) is divided by the power supplied to the LED. Another algorithm is to multiply the LED's optical efficiency by LED's radiation efficiency.
