(a)–comparison between M_phot for the best-fitting exponential and non-parametric SFHs, colour-coded by the ratio of p(> ​χ²) associated with the two models. Red colours indicate higher p(> ​χ²), hence higher quality of fit, for the non-parametric SFH. The inset shows the distribution of the p(> ​χ²) ratio, clearly skewed towards positive values. (b)–correlation of M_⋆/L_3.6 with L_3.6 for models with exponential SFHs. The trend is similar to the one for non-parametric SFHs shown in Fig. 1 but with larger scatter.