5 × 5 deg² box at 170° < l <  175°, −5° < b <  0° as observed in UVEX r band. This region is picked as representative of the more difficult and changeable (winter) observing conditions. Colours shown indicate the magnitude differences with respect to Pan-STARRS. Left: differences before calibration; centre: differences after calibration; right: differences after the small additional illumination correction is applied. White holes are excluded regions around bright stars.