Panel a) shows the core of the angle-averaged point spread function (PSF) of Hinode, normalized to unity at its peak, panel 1b) the same PSF multiplied by the radial distance r to visualize the contributions from different radial distances. Panel c) shows the variation of the encircled energy of the PSF with distance, with the approximate locations of the first three diffraction minima indicated with vertical lines. Panel d) shows a cut through the corresponding modulation transfer function. The 4 curves in each panel correspond to Case I (full), Case II (short dashes), Case III (long dashes) and Case IV (dash-dotted), summarized in Table 1.