Top panel: ⟨(S/N)_WL⟩_Δλ^* defined in the cluster redshift bins adopted for the stacking, namely z ∈ [0.1, 0.3), z ∈ [0.3, 0.45), and z ∈ [0.45, 0.8]. Bottom panel: Number of background sources as a function of z. In both panels, quantities obtained from the combination of colour and photo-z selections (solid black lines), colour selection only (dashed green lines), photo-z selection only (dashed blue lines), and photo-z peak selection are shown. The black and green curves are almost overlapping.