Composite luminosity functions including all clusters with a redshift lower than 0.67 (top panel), plus a richness higher than 6 (middle panel) or 10 (bottom panel). The black points represent the counts, whereas the blue regions show the 68% c.i. around the median parametrised composite luminosity functions (cyan lines). The red normalised histograms show the magnitude distributions of the BCGs of all clusters included in each bin. The grey points show the counts when there are fewer than 4.5 clusters contributing, and are not taken into account in the fitting procedure.