Recently, the CIE (International Commission on Illumination) issued a new technical report "CIE 224: 2017 CIE 2017 Color fidelity Index for accurate scientific use".  The main content to share with you is as follows.

As we all know, CIE color rendering index (CRI), especially the general color rendering index Ra, widely used in the lighting industry, is an important international and domestic standard and technical specifications used to evaluate the color of the light source. However, in recent years, with the development of solid-state lighting, CRI defects gradually highlighted. In many cases the value of Ra and the general observer can not match the visual assessment. This mainly includes two aspects: first it can not accurately characterize the color fidelity; and second is the lack of color quality perception related to the evaluation. So the CIE decided to adopt a better characterization method to measure and standardize the color quality of white light sources. The work is divided into two parts, one is that the TC1-90 is responsible for the development of more scientific and accurate color fidelity indicators, and the other is that the TC1-91  is to develop related indexes other than color fidelity and color perception.

The technical report CIE 224 is the achievement of TC1-90, proposing color fidelity of CIE 2017, namely, general color fidelity index (Rf). The Fidelity Index, defined in TM-30-15 of the North American Illuminating Engineering Society, mainly corrects the inaccuracies of CRI as color fidelity indicators.

Rf is the average of the degree of color close to the color of the swatches and reference light, similar to the general color rendering index Ra, but it only considers one aspect of the color quality and is not considering visual perception / preference and so on. So at this stage Rf can not replace the CRI. CRI alternative is a subject to study and discuss in the future. In addition to Rf, a series of new perception related to the color quality index will be developed.