Sky maps of all nine clusters. All plots have the same contrast scale for magnitudes to allow a fair visual comparison. Blue circles indicate the adopted cluster size based on the catalogue of Bica et al. (2008) that were increased in some cases to include more stars for the statistical field-star decontamination. Red circles are the smallest limit around the cluster considered to select field stars, which has a radius of 2.5′ for NGC 152, and 1.5′ for the others. The values are provided in Table 4.