Correlated Color Temperature is usually expressed in Kelvin’s of a blackbody radiator that most closely resembles the color of a stimulus of equal brightness.
Effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference illuminant.
In order to meet the new needs in the Solid State lighting industry and consumers for communicating color quality of all lighting products, Color Quality Scale (CQS) is being developed at NIST, which evaluates several aspects of the color quality of objects illuminated by the light source.
Illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception.
Color as described in the CIE1931 system can be plotted on a chromaticity diagram, usually a plot of the chromaticity coordinates x and y.
Wavelength of peak, the wavelength at which the intensity of a light source is maximum. Peak count, the maximum counts in the spectral diagram.
The dominant wavelength of a color is the wavelength of the spectrum color whose chromaticity is on the same straight line as the sample point and the illuminant point.
Excitation purity is the distance from illuminant point to reference point, divided by that from illuminant point to spectrum locus. The ratio used as a guide of the wavelength of spectrum color needed to be mixed with a reference color to give the specified color.
European Broadcasting Union (EBU) presented new evaluation standard for studio lights and luminaires, Television Lighting Consistency Index (TLCI).
Gamut area index (GAI) is a good indicator of color saturation. A light source with high GAI shows good color discrimination, saturation, and vividness. Choosing a source with high CRI (85 or greater) and a high GAI (80-100) is better. However, GAI higher than 100 might be saturated.