Ratio of the simulated and DR2 flux uncertainties (σ_sim/σ_data) as a function of data flux in the g (top), r (middle), and i (bottom) bands. The small points show the comparison between every simulated and observed object at every phase, and the larger points show the associated median binned values, both after correction for sky noise (see text for details). The blue curves (scimaglim) show the binned values obtained from the science image, and the grey curves (diffmaglim) show the binned values obtained from the difference-image limiting magnitudes, both without correction for sky noise.