A tomography appliance and method for a tomography appliance make it possible to calculate, in a simple and efficient manner, detector-element-related coefficients of an intensity function dependent on the detector output signal and to calculate the X-ray-emitter-related coefficients of an intensity function dependent on an X-ray emitter input value. This is done on the basis of measured detector output signals and at least one X-ray emitter input value, such that the intensity which acts precisely on the respective detector element can be determined from X-ray radiation originating from the X-ray emitter.