Ks-band AB Petrosian magnitude versus effective Ks surface brightness for the Ks_AB < 18.2, z < 1 sample selected in Fig. 9. The hard limit at the top-right hand side shows the size limit of 0.7″. The main galaxy population seems to have a high surface brightness limit of μ_Ks = 18. mag arcsec^-2, with a small group at higher surface brightnesses (shown as blue crosses) – either compact galaxies or stars that have managed to avoid all the selection criteria. Galaxies have surface brightnesses as low as μ_Ks = 24.0 mag arcsec^-2, but fainter galaxies would need to be selected before the VIKING surface brightness became a limiting factor.