Top panel: typical trends of S/N values within apertures with major semi-axis R, as a function of the normalized , for a subset of simulated double-Sersic galaxies. The curves are color-coded to show the morphological type of the synthetic galaxies, with red representing bulge-dominated objects, blue representing disks, and yellow-green representing double components objects with different bulge-to-total ratios. Bottom panel: values of the best S/N aperture dimensions as a function of the bulge-to-total ratio.