Comparison between the apparent magnitudes, m (top row) and the mean effective surface brightnesses, < μ >_e (bottom row) derived from the MTO measurements and the values reported in the literature for the dwarf candidates we used to train our model. We show the literature values on the x-axis and the values measured by MTO on the y-axis. The data points are color coded by the survey they were identified in as shown in the figure legends. The one-to-one relation is plotted as the gray dashed line. The red dashed line in the top row plots shows a linear fit to the data that can be used to correct the magnitude offset from the one-to-one relation. We report the standard deviation of the residuals with respect to this linear fit σ_res in the legend. Left column: g band, right column: r band.