Top panel: detection bias for galaxies with 20 < m_AUTO < 24.5 as a function of r_sep, the distance to the nearest object detected by SEXTRACTOR (black points). The open grey points show the detection bias as a function of the nearest neighbour in the input catalogue brighter than m_input = 26 (grey open points). For reference, the hatched region indicates the detection bias for the grid-based simulations. Bottom panel: fraction of galaxies that have a neighbour within a distance < r_sep in the input catalogue (grey dashed line) or detection catalogue (black line). For small separations many of the true blends are not recognised as such.