Top left: comparison of photometric redshifts for the 19 common clusters from our sample and the SCS cluster survey from Menanteau et al. (2009) and Menanteau et al. (2010). Top right: comparison of masses for the same cluster sample in the r₂₀₀ aperture determined from the measured X-ray luminosity through scaling relations (x-axis) and the mean of the optically determined masses ) and M(N₂₀₀) (Table 5). The red line marks equality in both top panels. Bottom left: photo-z difference Δ =  photo-z(SCS)  −  photo-z(XMM-BCS) as a function of our estimates of redshifts. Bottom right: M₂₀₀ difference Δ = M₂₀₀(SCS)  −  M₂₀₀(XMM-BCS) as a function of our estimates of redshifts. The optical masses are significantly higher than the X-ray estimates especially at the low and high redshift ends. See text for discussion. Green points in all plots mark clusters from M10, black points those from M09.