Same as Fig. 6 , but with overlaid isochrone curves to exemplify the fitting process. The solid blue curve represents the best-fitting isochrone resulting from the complete procedure. The dashed lines illustrate the same theoretical model shifted when choosing different comparison points; the red curve corresponds to a lower E(J − Ks)_i value (1.36), while the black curve corresponds to a higher value (1.43) than that obtained for the optimal solution (blue curve).