Upper panel: the figure of Merit for all cosmological parameter space FoM_TOT as a function of the number of photo-z bins used for tomography N_zbin, shown for ϵϵ (dashed line), nn (dotted line), and all (solid) correlations. The grey line corresponds to results for lensing only (GG). Throughout, N_K = N_Z = 5 nuisance parameters for the bias terms are used. These results are obtained for the standard set of parameters and σ_ph = 0.05. Lower panel: same as above, but in terms of the dark energy figure of merit FoM_DETF.