Diagnostic plots for the determination of the distance, the reddening, and the age of M75. Left panel: CMD of M75 (gray dots) with the best-fit BaSTI isochrone computed with [Fe/H] = −1.3 dex plotted as a solid red line. The dashed red isochrones represent the uncertainties on the parameters. The black circles mark the stars used for the isochrone fitting procedure. The resulting best-fit values of color excess, distance modulus, and age are labeled. Right panel: corner plots showing the 1D and 2D projections of the posterior probability distributions for all the parameters derived from the MCMC method. The contours correspond to the 68%, 95%, and 99% confidence levels.