Residuals of the comparison between PS1 and J-PLUS photometry in the r band, , as a function of the (X, Y) position of the source on the CCD. Upper left panel: stacked residual map of all the J-PLUS DR1 pointings. Upper right panel: stacked residual map after applying the plane correction estimated pointing-by-pointing. Lower left panel: residual map of the pointing p_id = 00315. The gradient in the residuals of the individual sources (coloured circles) is fitted with a plane (coloured squares). The direction of maximum variation is shown with the arrow. Lower right panel: residual map after applying the plane correction.