PSF surface-brightness profiles versus the radius r for a 0 mag point source, from references that are discussed by B07. Individual PSFs are drawn with coloured lines and symbols as indicated in the figure, see also Table 1. PSF_K71, PSF_V,0m, PSF_i,0m, and PSF_CV,2 are shown in this figure as references. The light grey region indicates the PSF core, and the white region the aureole, as defined for PSF_CV,1 and PSF_CV,2 (CV83).