Full-field ExPo image of the circumstellar environment of SU Aur in polarised intensity, taken without filter. The intensity scale is logarithmic over two orders of magnitude and north is up and east is to the left. The polarisation vectors plotted on the image indicate the fraction of polarised light (P_I/I). At the very centre of the image the vectors are unrealistically small because the total intensity of the star dominates the polarised light. As explained in the text, our derived polarisation degree is a lower limit to the real value.