An object radiography apparatus includes a radiation source configured to generate and emit an electromagnetic radiation for radiographing an object, a detector device, which is arranged in such a way that the emitted electromagnetic radiation which passes at least partly through the object impinges at least proportionally on the detector device, and which is configured to generate a radiograph of the object. In addition to the detector device, a sensor arrangement is provided, which is configured to determine a radiation characteristic variable assigned to the radiation source. An evaluation unit is configured to determine or to receive a quality parameter of the detected radiograph, to evaluate the radiation characteristic variable and to make a statement about a state of the detector device and/or of the radiation source on the basis of the quality parameter and the radiation characteristic variable.