A method for testing the spatial distribution of a coating or an impurity on a surface of a test object, the method comprising the following steps: illuminating the test object with the coating or the impurity with electromagnetic excitation radiation having a first wavelength, detecting electromagnetic luminescence radiation emitted by the coating or the impurity on the surface of the test object, wherein the luminescence radiation comprises a second wavelength different from the first wavelength, generating object data from the detected luminescence radiation and outputting the object data, wherein illuminating the test object with the coating or the contamination is carried out from a plurality of spatial directions, wherein detecting the luminescence radiation from the coating or the impurity on the surface of the test object is carried out in a plurality of spatial directions, and wherein the test object flies along an object test path during illuminating the test object and detecting the luminescence radiation, wherein illuminating the test object with the coating or the contamination is carried out with an object illumination unit with a plurality of illumination elements in the form of an LED, an LED floodlight, an LED array or a laser, wherein the object illumination unit is configured and arranged in such a way that it illuminates the test object with a light output per unit area on the surface of the test object of 0.01 W/cm 2 or more, wherein detecting the luminescence radiation is carried out with an object detection unit, wherein the object illumination unit and the object detection unit co-operate in such a way that an integration time per detected pixel of the test object of less than 5 tenths of a second results, wherein the object detection unit comprises at least three detectors, each of the at least three detectors with an observation field, wherein the observation fields of the detectors together cover a sphere, wherein the object detection unit is arranged and located in such a way that it detects the test object from the plurality of spatial directions with the at least three detectors, wherein the detectors are configured as imaging cameras, and wherein an object pose detection unit detects at least the spatial position or the orientation of the test object on the object test path relative to the object pose detection unit. illuminating the test object with the coating or the impurity with electromagnetic excitation radiation having a first wavelength, detecting electromagnetic luminescence radiation emitted by the coating or the impurity on the surface of the test object, wherein the luminescence radiation comprises a second wavelength different from the first wavelength, generating object data from the detected luminescence radiation and outputting the object data, wherein illuminating the test object with the coating or the contamination is carried out from a plurality of spatial directions, wherein detecting the luminescence radiation from the coating or the impurity on the surface of the test object is carried out in a plurality of spatial directions, and wherein the test object flies along an object test path during illuminating the test object and detecting the luminescence radiation, wherein illuminating the test object with the coating or the contamination is carried out with an object illumination unit with a plurality of illumination elements in the form of an LED, an LED floodlight, an LED array or a laser, wherein the object illumination unit is configured and arranged in such a way that it illuminates the test object with a light output per unit area on the surface of the test object of 0.01 W/cm 2 or more, wherein detecting the luminescence radiation is carried out with an object detection unit, wherein the object illumination unit and the object detection unit co-operate in such a way that an integration time per detected pixel of the test object of less than 5 tenths of a second results, wherein the object detection unit comprises at least three detectors, each of the at least three detectors with an observation field, wherein the observation fields of the detectors together cover a sphere, wherein the object detection unit is arranged and located in such a way that it detects the test object from the plurality of spatial directions with the at least three detectors, wherein the detectors are configured as imaging cameras, and wherein an object pose detection unit detects at least the spatial position or the orientation of the test object on the object test path relative to the object pose detection unit.