Measurements of Human Sensitivity to Comb-filtered Spectra

Using a novel stimulator that incorporates a liquid crystal display, the spectral modulation sensitivity function of the colour vision system was derived by measuring discrimination thresholds for comb-filtered spectra. This function shows a peak of sensitivity at 0.97 c/300 nm with a plateau that extends to 1.67 c/300 nm. Extrapolation of the curve gives an estimated high-frequency cut-off at 5 c/300 nm. The thresholds are also transformed to the CIE (1931) diagram and the elliptical isosensitivity contours thus obtained are compared with the classical discrimination ellipse of MacAdam for the corresponding region of colour space.