Comparison of magnitudes of simulated GCs. Left column: Comparison of input and output I_E magnitudes of the simulated GCs. The distributions of measured magnitudes from the Euclid photometry pipeline are plotted against the input values, with the mean and the extremes marked with horizontal bars. From top to bottom we show the results for simulated FoV 1, 2, 3, and 4, which correspond to increasing galaxy distance. The solid line marks the 1:1 relation. Right column: Histograms of the differences between the input and output I_E magnitudes for the GCs for the same four FoV.