K band counts for the 49.75 arcmin² GMASS field. Also indicated on the right-hand axis are counts/mag/arcmin². The solid histogram is for the 3.3σK band catalogue, while the dashed histogram is for the (faint) 2.2σ catalogue. The filled histogram indicated which objects are in the GMASS catalogue (i.e., are counterparts of an unblended 4.5 μm source). The vertical dashed line indicated the completeness limit for the 3.3σ catalogue. Overplotted are counts from Gardner et al. (1993, green/light line) and Saracco et al. (2001, blue/dark line).