Solid histograms show distribution of magnitude (left) and redshift (right) for the quasar candidates for the ‘point-like’ and ‘all’ samples (see Table 1). Both distributions look similar, except for a peak at z ~ 3, present only when extended sources are included, suggesting the code might also work for extended sources. For comparison, empty histograms show the same distributions for the 1 deg² test sample. We note that the redshift used here is the best trial redshift for each candidate.