Figure 4.

(A) Spectral irradiances of the blue, green and red channel on the RGB screen, and the respective peak wavelengths, as measured with a commercial photospectrometer (Gossen, MAVOSPEC BASE, Nuremberg, Germany). The dotted line shows the chromatic defocus function, relative to 570 nm, as provided by Marcos et al.²². Black numbers indicate the luminance, separately measured with a Minolta candela meter (LS-100, Minolta Camera Co., LTD, Tokyo, Japan). Point spread functions for the chromatic blur were calculated relative to 570 nm (Fig. 3). (B) Illustration of images filtered with the “blue in focus” and “red in focus” filter. Note that image with “blue in focus” filter appears more blurry than the image with “red in focus” filter because the human visual system uses M and L cones for high acuity tasks and blur in red and green has higher impact of visual acuity.