Comparison of the subtraction of a star with GALFIT3.0, using a 15 arcsec Tiny Tim PSF (upper row) and our combined PSF (lower row). Top left panel: F775W image of a star. Bottom left panel: intensity profiles for the star, the PSF models and the residual images after the subtraction of the Tiny Tim PSF and after the subtraction using our combined PSF (see the legend for details). Middle column: PSF scaled models for the Tiny Tim model (top) and the combined PSF (bottom). Right column: residuals of the subtraction for the Tiny Tim model (top) and the combined PSF (bottom). We note that the residuals for the wings in case of using our combined PSF are smaller at all radii than those resulting from using the Tiny Tim PSF, despite the common central underestimate. The FoV of all the images is 24 × 24 arcsec². All images are in the same colour scale.