Power-law exponents of the effective attenuation laws measured in the visible (upper panel) and NIR (lower panel) are plotted against the attenuation in the V band, A_V . and compared to the mean relations of Chevallard et al. (2013) plotted with a thick line, the thin lines corresponding to the 1σ uncertainty. The values obtained with the DBPL-free and the Calzetti-like modeling are plotted with filled squares and dots respectively. The one σ uncertainties are reported for each quantity.