TRADE-OFF BETWEEN COLOR FIDELITY AND COLOR GAMUT: A CASE STUDY (PO09, 856-861)

With the Illuminating Engineering Society of North America (IES) method, including a colour fidelity index (Rf) and a colour gamut index (Rg), for evaluating the colour rendition properties of light sources, the trade-off relationships between colour fidelity and colour gamut were investigated theoretically by optimizing the peak wavelengths, spectral widths, and relative intensities of four-channel LEDs at the correlated colour temperatures (CCTs) ranging from 2800 to 6500 K. The results indicate that the highest scores of Rg at all the selected CCTs indeed decrease with the increasing Rf, and that the pattern of the trade-off between Rf and Rg is almost independent on the CCT. Furthermore, it is feasible to seek out a set of four peak wavelengths for relatively high colour fidelity as well as large colour gamut at different CCTs.