Point-spread matrix (PSM) at a wavelength of 820 nm for a converging beam of light with an f-number of 61.3 that reflects off gold at an angle of incidence of 45°. The panels show the central 100 μm × 100 μm of the PSM elements. The positive x- and y-directions are upward and to the left, respectively. The gray plus signs indicate the centroids of the PSM elements in the absence of diffraction and aberrations. The values of the color maps are different among the panels.