The invention relates to a method for determining the image quality of an optical imaging system and to the use of the inventive method for determining the influence of samples on the amplitude distribution and on the phase front distribution of the illuminating light of which the amplitude distribution, in particular, is known. The invention comprises the following steps: adjusting the subassemblies relative to one another whereby making it possible to project images of a sample onto the detection device; recording a number of images of the sample from different planes of reference near the best focus plane; improving the image quality by image processing, particularly by reducing the noise in order to compare local sensitivity differences of the detection device and to center the intensity concentration points at a predetermined location in the images; computational linking of locally resolved image information, of the set values and system values related to the optical imaging system, and of information concerning the sample with the aim of determining characteristic numbers that are characteristic of the wave front deformation caused by the imaging system, and; outputting the characteristic numbers and assigning them to the imaging system in order to describe the image quality.