Radial distribution of the difference between the logarithm of the observed [S III]λ9532 flux and that of the best-fit model (both normalised to Hβ) predicted by IZI, in eight stellar mass M_⋆ bins, as reported in the legend. The shaded regions represent the 16th and 84th percentiles of the distribution in each stellar mass bin taking into account the number of galaxies lying in the bin. This figure clearly shows that [S III]λ9532 is largely overestimated, with differences between observed and predicted fluxes of up to 0.8 dex.