Abstract: The present invention relates to an X-ray source for irradiating an object to be imaged with X-ray radiation, wherein the X-ray source is moveable into a plurality of defined recording positions relative to the object to be imaged. A module is arranged directly on the X-ray source, said module being designed to project a marking onto the object to be imaged and/or to check a position of the object to be imaged and/or of the marking, wherein the module for checking the position of the object to be imaged and/or of the marking comprises a detector for optical radiation. In addition, the present invention relates to an X-ray device comprising the X-ray source and a method for using the X-ray device.