Best-fitting stellar population properties. Posterior distributions for one of the spatial bins of FCC 167 showing that our FIF approach is able to recover the stellar population properties with high precision, breaking the degeneracies among them. Vertical red lines indicate the best-fitting value (solid line) and the 1σ uncertainty (dashed lines). These values are quoted on top of the posterior distributions. The luminosity-weighted age of this bin is 12.7 Gyr.