Modern light sources (light emitting diodes, organic light emitting diodes) have considerable flexibility in creating a wide range of colours and brightness of lighting devices and monitors in which they are used. Evaluation of the homogeneity of the chromaticity of radiation is carried out using the colour thresholds obtained in the McAdam experiment and named after their shape McAdam ellipses. This experiment was carried out under the same observation conditions. Their application in practice is limited and requires research in a wide range of observation conditions. To date, in colorimetry, there is a colour perception model CIECAM02, which is approved by the CIE (International Commission on Illumination). This model allows you to recalculate the chromaticity coordinates for observation conditions that are different from the initial conditions. In this work, a model of the CIECAM02 algorithm is implemented and a study is made of the transformation of McAdam ellipses under changing observation conditions. The result of the study demonstrates the change in the position of the ellipses on the CIE 1931 colour chart, as well as their shape. The data obtained allow us to speak about the relevance of further research on the perception of white colour radiation in a wide range of chromaticity and brightness in order to improve the algorithms of the colour perception model.
1. Methodological Guide to the Design of Dynamic Lighting in Public Buildings [Metodicheskoye rukovodstvo po proyektirovaniyu dinamicheskogo osveshcheniya v obshchestvennykh zdaniyakh] / Ministry of Construction and Housing and Communal Services of the Russian Federation, Federal Autonomous Institution “Federal Centre for Regulation, Standardization and Technical Conformity Assessment in Construction”, Moscow, 2019.
2. Standard: GOST R34819–2021. Lighting devices: Lighting requirements and test methods [Osvetitel’nyye pribory: trebovaniya k osveshcheniyu i metody ispytaniy] / Moscow, 2022, 49 p.
3. McAdam, D.L. Visual Sensitivities to Colour Differences in Daylight // Journal of the Optical Society of America, 1942, Vol. 32, # 5, pp. 247–274.
4. LED Lighting, Technology and Perception / T.Q. Khanh, P. Bodrogy, Q.T. Vinh, and H. Winkler, Wiley-VCH, 2015, pp. 299–301.
5. Kuehni, R.G. Threshold colour differences compared to supra-threshold colour differences // Colour Res., 2000, No. 25 (3), pp. 226–229.
6. M.D. Fairchild, Colour Appearance Models, 2nd. ed., Wiley, Chichester, 2005
7. Proskurin O.A., Budak V.P. Measuring Colour Thresholds // Pattern recognition and image analysis, 2006, Vol. 16, # 1, pp. 37–38.
8. Matveev A.B., Belyaeva N.M. Equal contrast colour system [Ravnokontrastnaya tsvetovaya sistema] // Svetotekhnika, 1965, #9, pp. 1–6.

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• McAdam ellipse
• colour temperature
• adaptation luminance
• chromatic adaptation
• CIECAM02
• colour appearance model