Luminosity Curve, CIE
Graph representing the luminous intensity of wavelengths in the visible spectrum relative to the maximum intensity at the same wavelength. The relative luminosity curve is described by the Y color matching function in the CIE System. The shape of the curve depends on the area of the retina being stimulated and on the intensity of the incident light. Thus, the CIE luminosity curves for the 2° and 10° observers are slightly different, and those for daylight vision, i.e., photopic vision, and for dark adapted vision, i.e., scotopic vision, are extremely different.