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:
- <math>\frac{ \int^{\lambda = \infin}_{\lambda = 0} y_\lambda J_\lambda d\lambda } { \int^{\lambda = \infin}_{\lambda = 0} J_\lambda d\lambda }</math>
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.