Age and metallicity distributions of the input mocks (black) compared to the output of DirSFH. The first column shows the old and metal-poor mock peaking at 12.3 Gyr and −2.0 dex, with blue being the smaller sample (N_S stars) than red (N_T stars). The second column shows the younger, slightly more metal-rich mock (mean age of 10.3 Gyr and [Fe/H] of −1.7 dex) with blue corresponding to the smaller sample of size N_S and orange the larger sample of N_T stars. The top row shows the contours of the 2D distributions containing the percentage of stars within 1,2 and 3σ levels in 2D. The middle row shows the 1D metallicity distributions and the bottom row the age distributions, where the errors come from averaging over the 100 solutions produced by DirSFH. In the bottom two rows, the input for the samples of size N_S are shown with dashed lines to distinguish between distributions. Errors on the input distributions, plotted as black error bars, are taken as $\sqrt{N}$ per bin.