Fraction of the photometric completeness as a function of the observed magnitude in W3 Main (left), the control field (middle) and the IRSN3 subregion of W3 Main (right). The dashed lines show the average completeness fraction for the K_s-band, the solid lines the H-band and the dotted lines shows the J-band completeness fraction. The resulting average 50% completeness limits are given in Table 1.