NACO K_s mosaic of fields in the Quintuplet (left) and Arches (right) clusters. The same fields are approximately covered in L′. In the Arches cluster, Field 2 is not shown and is located to the lower right of the cluster (see Fig. 1). Disc candidates are indicated in both clusters as white circles. Yellow circles in the Quintuplet mark disc candidates fainter than the completeness limit of J = 22 mag in the left panel. Previously known disc candidates in the Arches detected in our earlier higher-resolution Keck/NIRC2 observations are included for comparison as smaller cyan circles in the right panel (Stolte et al. 2010). The star serving as coordinate reference for all catalogues is indicated by the arrow.