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The intelligent way of lighting.

Luminous Efficacy

What are scientist talking about when they speak about `luminous efficacy`? You can read terms like the figure merit for light sources or the ratio of luminous flux to get power ect. In simple words it is indeed the luminous flux that is being emitted from a light source to the electric power by the source. It describes how the source provides us with visible light from electricity. Luminous efficacy of radiation (LER) gives us a certain spectrum which describes very well how sensitive our sight is (our eyes) to the mix of wave lengths that is involved here. The LER can be compared to an emission spectrum. It shows the conversion efficiency from electrical energy to electromagnetic radiation.

Wavelengths of lights outside of the visible spectrum are not useful from illumination because they cannot be seen by our human eye. The human eye is a very complex and sensitive organ. The response of the eye to the wavelengths is then represented in the luminosity function, because the eye reacts under bright conditions a certain way as well as it does under dim conditions. Brief, luminous efficacy of radiation measures the fraction of electromagnetic power that is useful for lighting. It is a very powerful tool when inventing new ways to save energy in modern lighting technology.