Medians of the absorption correction U for the objects in the XMM-LSS, XMM-CDFS, and XMM-COSMOS surveys, over a grid of redshift and observed luminosity. Probability distributions for photometric redshifts have been included. The corrections are mostly significant for objects in the faint tail of the luminosity function (i.e. L ≲ 43–44.5, depending on z), or for z ≳ 3. The correction U (Sect. 3) is logarithmic, hence U = 0.5 corresponds to the luminosity being corrected by a factor of 2. The colour scale goes from black (median correction is 0) to bright yellow (median correction is 0.6). White areas are not populated.