Upper panel: observed HB and RGB of Tucana. The crosses on the left-hand side illustrate the average photometric uncertainty as a function of magnitude Lower panel: synthetic CMD obtained with the SFH of Monelli et al. (2010b). A theoretical isochrone for t = 8 Gyr and [Fe/H] = −1.27, which has a mass at the RGB tip of 0.92 M_⊙, is superimposed (green). The blue track represents the evolution of HB stars coming from this stellar population and experiencing RGB mass loss as prescribed by Salaris et al. (2013). The red track shows the evolution of the same stars, but with no RGB mass loss.