2413 20160701171705.0 ASTROimport-570 Hensberge, H. 1993 On the imaging quality of some CCD systems at ESO. CCD blemishes might limit the final accuracy in high S/N applications. Mapping of these blemishes, often not very apparent in the original data, but relevant with respect to the final aimed accuracy, permits to undertake proper actions in the data reduction procedure. The authors discuss the CCD tests performed at some of the ESO telescopes. Brown, A. G. A. Verschueren, W. de Geus, E. J. European Southern Observatory Conference and Workshop Proceedings 47 1993 http://esoads.eso.org/abs/1993ESOC...47...81H published in NONREF