Major- and minor-axis disk profiles (upper and middle rows) showing the deviations from a general Sersic profile due to the combination of dust and projection effects. Solid upper curves are for B-band dusty disk images, for , dashed curves are for corresponding Sérsic fits, while absolute residuals (simulation − fit) are represented by solid lower curves. The fits were made by leaving the geometrical coordinates of the intensity peak as free parameters. The cuts were taken parallel and perpendicular to the major-axis of the simulated dusty disk images, through their intensity peaks, at inclinations 1 − cos(i) = 0.3,0.7,0.9 (i = 46°,73°,84°). The light green line shows a cut through the geometrical centre of the image. Lower row: corresponding relative residuals , at the same inclinations and opacity as the profiles. The red lines show radial and vertical cuts through the geometrical centre of the image.