Dependence of photometric redshift uncertainty (left) and star classification performance (right) as a function of i-band magnitude. The left hand side figure shows the median 1 − σ interval per 0.5 magnitude bin. The right hand side shows the purity and completeness of the star classifier per magnitude bin. The purity of the classification remains high (>80%) up to i_AB = 23 and decreases sharply closer to the detection limit (see also Fig. 2b). Similar behavior is found for all classification categories.