Top: magnitude distribution of PN candidates from the SuprimeCam survey (hatched blue histogram) and PNe from the e²PN.S survey (hatched red histogram) in the region of overlap highlighted in Fig. 5. The magnitude distribution of objects identified in both surveys is shown in purple. The vertical lines denote the limiting magnitudes of the two shallowest e²PN.S fields, and the shaded grey region denotes magnitudes fainter than the limiting magnitude of the SuprimeCam survey. Bottom: magnitude distribution of PN candidates from the SuprimeCam survey with no counterpart in the e²PN.S (purple). The hatched histogram shows the expected distribution of background Ly-α galaxies at redshift z = 3.1 in the region of overlap scaled by the photometric completeness of the SuprimeCam survey.