Summary of the surface photometric analysis of KIG 620 (top panels). Deep g and r images are shown, with isophote contours down to the 2σ level of the sky. Middle panels: the right g image enhances the central part of KIG 620, showing the ring structure, and the left panel shows the g and r light profiles. Bottom panels: as in Fig. 5, but for KIG 636. The B+D model is shown. We show 20 isophote levels, between 500 and 2 σ of the sky level, for the original and model images.