1. A method for optically detecting deviations of an image plane of an optical imaging system from a surface of a substrate arranged in a vicinity of the image plane comprising: positioning the imaging system relative to the substrate such that a working distance between a final optical surface of the imaging system and the substrate surface is on the order of an operating wavelength of the imaging system or smaller than the operating wavelength; generating at least one measuring beam of measuring light; irradiating an intermediate zone situated between the final optical surface of the imaging system and the substrate surface with the measuring beam; and detecting the measuring beam subsequent to reflection of the measuring beam at the substrate surface.