Relation between X-ray luminosity and intrinsic richness for the sample of richest detections (λ_⋆ > 20, S/N > 4.0, z < 1.6) that were found to have non-significant X-ray emission, with X-ray measurements performed with (top panel) and without (bottom panel) point-source removal. Empty squares are detections with X-ray flux below the 1σ significance limit. The grey shaded area in the background is the 2σ scatter region relative to the L_X − λ_⋆ relation found at z_ref for the full r-band-detected sample.