Offset between PODC and DR2 calibrated sources as a function of DR2 G magnitude.Sources must have a minimum of 10 Gaia transits for inclusion, and were selected to have overlaps with the SDSS footprint, hence avoiding regions of low Galactic latitude and high extinction. A simple quadratic model (shown as a dashed red line) shows the residual magnitude dependence for sources fainter than G = 16.