Procedure to select stars with high-quality photometry and astrometry. Top panels: RADXS and qfit parameters derived from F336W (left) and F814W (right) photometries of stars in the field of view of Reticulum. The azure lines separate well-measured stars (black dots) from poorly measured sources (gray crosses). Bottom panels: instrumental F336W vs. F336W − F814W CMD for stars that pass the selection criteria in both filters (left) and for the remaining stars (right).