At a glance

摘要

A measurement of the colour quality of light, done by assessing how far an object's colours under the test lamp conform to those under a CIE reference illuminant.rnOriginally there were eight reference colours, in categories 1 A, 1B etc, with results expressed in Ra. There are now 14 colours, with results expressed in CRI and the percentage achieved.rnTypically, incandescent and halogen sources achieve CRI 100; a Ceramic Metal Halide Lamp will achieve CRI 85-92 and fluorescents CRI 75-85.