Same as Fig. 9 but this time, the mock catalogue was generated by first reddening the simulated sources by an extinction law whose characteristic R_V is allocated randomly from a normal Gaussian distribution with a mean of 3.1 and a standard deviation of 0.2. The photometry is then “de-reddened” by the Galactic extinction value derived for a fixed R_V = 3.1 at fixed p_B5D. In doing so, we can therefore assess the impact on photo-z of neglecting the uncertainties on R_V from the divergences from the identity line.