The Illuminating Engineering Society of North America (IES) issues today a position statement recognizing that the long-established use of the Color Rendering Index (CRI) is an outdated metric because of today’s light source technologies. While CRI has served as an indicator of color rendering since 1964, it is no longer a useful tool because of the many ways in which LEDs can create white light resulting in a variety of spectral power distributions. CRI cannot describe or rank the color rendering abilities of these light sources, therefore making it an unreliable indicator for how a white light source renders color in objects. IES, as well as the international lighting community, is reviewing possible new methods for measuring color quality of white-light sources. To that end, the IES has established a Color Metrics Task Group to evaluate CRI in face of all the other metrics in use around the world to determine what path the Society should pursue – perhaps adopting one or more of those metrics; recommending a methodology for evaluating color quality leading to a new metric; recommending more research. PS-8-14 Color Rendering Index position statement can be accessed on the IES website at www.ies.org/store/position_statements.cfm.
