High-CRI LED lighting

[3] In 2008, the U.S. Department of Energy created the L Prize to find an incandescent light bulb replacement that met efficiency metrics and had a CRI above 90.

[5] CRI is calculated from the differences in the chromaticities of eight CIE standard color samples (CIE 1995) when illuminated by a light source and by a reference illuminant of the same correlated color temperature (CCT), commonly measured in kelvins, indicating the light color produced by a radiating black body at a certain temperature; the smaller the average difference in chromaticities, the higher the CRI.

[2] For CCTs less than 5000 K, the reference illuminants used in the CRI calculation procedure are the spectral power distributions (SPDs) of blackbody radiators; for CCTs above 5000 K, imaginary SPDs calculated from a mathematical model of sunlight are used.

Its color sample set has just 8 items, which is too few to test lights with complex spectra.

A light manufacturer can tune its SPD to the sample set so as to achieve an artificially high CRI.

Color Rendering Index (CRI) is determined[9] by the distinctions in the chromaticities of fifteen test color samples (TCS), where objects are illuminated by the light source to be evaluated and a reference illuminant with the same CCT.

Therefore, it is important to check certain Ri numbers in the extended CRI, such as R9 and R12 which represent two significant colors for film/video and medical lighting.

As a result, color rendition can be unpredictable in optical prints or in transfers to digital media from film and video camera recordings.