Top row: observed colour–magnitude diagrams for the seven clusters, showing all stars for which photometry was obtained. The red dashed curves indicate the approximate 50% completeness limits, while error bars show typical photometric errors. Second row from top: Colour–magnitude diagrams for background annuli. Third row: Background-subtracted CMDs (see text for details). Bottom row: simulated CMDs, using Bertelli et al. (2009) isochrones for the ages and metallicities listed in the legends.