Magnitude distribution of sources during the matching process. The black, blue, and red lines denote the total, background, and real sources, respectively, as described in the text. The two upper histograms (panels a and b, for the inner and outer part of the field, respectively) correspond to the match where the blocking effect is present. Correction for blocking effects mitigates the issue of negative counts. The two bottom histograms (panels c and d, for the inner and outer part of the field, respectively) are the magnitude distributions after the blocking effect has been accounted for.