DAOPHOT quality indices r₀ and χ as a function of the magnitude for all sources detected within 2′′ of non-saturated R08 objects, in each UKIDSS band. The different lines show the thresholds defining the bad-quality flag in a particular filter: | r₀ | = 2 in the top panels, and the curve χ_lim(m) in the bottom panels (derived empirically as described in the text). A source was considered as having bad-quality photometry in a given band if | r₀ | > 2 or χ > χ_lim(m).