Abstract: The invention relates to an X-ray examination apparatus which includes an X-ray source and a diaphragm unit which is connected to the X-ray source and is provided with shutters for limiting a radiation cone beam emanating from the focal spot of the X-ray source, and also includes a light source for generating a light cone beam which traverses the shutters via a mirror. When the dimensions of the light-emitting parts of the light source are significantly larger than the focal spot, the irradiation field irradiated by the radiation cone beam is smaller than the illuminated field illuminated by the light cone beam. In order to match the irradiation field with the illuminated field, the shutters are provided with correction shutters which are transparent to X-rays but impervious to light and limit the light cone beam.