Comparing the old Stellar Population in Globulars and Dwarf Galaxies: The Cases of Phoenix and Leo A

Due to their star formation history (SFH), the stellar population in Dwarf Galaxies (DG) is likely to have a metallicity spread which is best traced by the morphology of the Red Giant Branch (RGB). We probe here a purely empirical approach aimed at estimating average metallicity (Z) and Z spread by comparing the Color-Magnitude Diagrams (CMD) of galactic Globular Clusters (GCs) with those of two DGs: Leo A (HST data) and Phoe (VLT Fors2 data).