Comparison of modern methods for estimating color rendering of light sources

The color rendering of light sources is important both in certification and in the practical application of light sources in various fields. The color rendering index R-a is the main normalized parameter that is responsible for the color rendering of light and is required for the certification of lamps. Therefore, it is important for the method of measuring and calculating the R-a index to be in the best compliance with the visual assessment of consumers. In Ukraine, from 01.01.2019, DSTU CIE 013.3:2017 "Method of Measurement and Determination of Color Rendering of Light Sources" (CIE 013.3-1995, IDT) was put into force to replace GOST 23198-94 "Electric Lamps. Methods of Measuring Spectral and Color Characteristics of Parameters". Numerous scientific publications indicate the drawbacks of CIE 13.3-1995 due to new studies in the physiology of the human eye and colorimetry in general. The results of these and other studies were taken into account in IES TM-30-15 method, and subsequently in CIE 224:2017 and IES TM-30-18 methods. The article presents a comparative analysis of the methods of calculating the CIE 13.3-1995 and the IES TM-30-15 color rendering index, as well as the publications of CIE 224:2017 and IES TM-30-18 reports, which take into account the inaccuracies of the previous methods. The characteristics on which the analysis has been carried out, the main differences of the methods of calculating the color rendering index are given. The results of world researches on new methods are analyzed. The analysis has revealed that the new IES TM-30-18 method has several advantages over CIE 13.3-1995. This method takes into account all the comments of the previous methods and provides users with more detailed information about the light source in terms of shift of saturation, color and hue.