Dependence of pipeline measured source ellipticity on the distance to the instrument rotator centre. The data are from IGAPS field 6395o and show the sources from the g image r584231 on the left, and from the U_RGO image r584230 on the right. On the left the data of all four CCDs are shown together with a running median plotted as a black line. On the right the data from each CCD are shown with different colours and symbols: CCD#1 as red filled dots, CCD#2 as blue plus signs, CCD#3 as green triangles, and CCD#4 as orange squares.