The invention relates to an apparatus (2) for detecting imaging quality of an optical system (4) with at least one lens (6) or lens group. The apparatus (2) includes an MTF measuring apparatus (10) for measuring a modulation transfer function at a plurality of field points in the field of view of the optical system (4), and a centering measuring apparatus (18) for measuring a centered state of the optical system (4). Furthermore, the invention relates to a method for detecting imaging quality of an optical system (4) having such a apparatus (2).