Point-source test for PN candidates in M 105. Left column: colour-selected PNe candidates. Right column: simulated PNe. Top row: half-light radius R_h as function of magnitude m_n. Bottom row: m_n − m_core as function of magnitude m_n. In each panel, blue dots denote the PNe candidates selected based on their point-like appearance. Left column: red crosses denote cross-matches with the PN.S catalogue, which place additional constraints on the morphology of the selected PNe candidates from Subaru photometry.