Relative difference between various estimates of ΔΣ_gm, based on different assumptions for source and lens redshifts, and the fiducial estimate in the data at 0.5 <z < 0.7. The quantity shown in the figure is as a function of the projected separation r_p. The fiducial estimate is that obtained by using Eq. (13), which includes the individual redshift probability distribution function p_s(z) of the sources, and for the lenses, the VIPERS spectroscopic redshift (z_spec) when available or the CFHTLenS maximum likelihood photometric redshift (z_phot) otherwise (see text). It corresponds to the adopted estimate for the analysis. The grey shaded area represents the relative statistical error expected in the survey.