Main Page | See live article | Alphabetical index The luminous coefficient is a coefficient that measures the integrated fraction of the radiant power that contributes to its luminous properties as evaluated by means of the standard luminosity function. The luminosity coefficient is: Where yλ is the standard luminosity function and Jλ is the spectral power distribuiton of the radiant intensity. The luminous coefficient is unity for a narrow band of wavelengths at 555 nanometers. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.