Distortion maps of the 16 VIRCAM detectors after astrometric calibration with S CAMP. Each panel is labelled with the calibration setting used: Fix_Focalplane (top) and Unchanged (bottom). The distortion pattern in the Unchanged case is consistent with the expected optical behaviour of a wide-field telescope, with minimal distortion near the centre and increasing distortion towards the edges. Pixel scale variations are colour-coded, with the corresponding scale bars shown to the right of each panel.