I-band-derived sharpness parameter versus I₀ band magnitudes of objects found in both I and V band combined images of VIMOS Quadrant 2 (objects detected in only one filter have been excluded). In the left panel, stars lie along the ridge of objects at the sharpness value of zero, while non-stellar or double stars lie mainly in the spread of points to the right of the ridge. Right panel: zoomed in version of the left panel. The dashed lines mark the sharpness values of −0.10 < sharpness < 0.03, in which range we have defined objects as point sources.