A method to show a predetermined volume segment of an examination subject by means of a tomosynthesis apparatus, and a correspondingly designed tomosynthesis apparatus, operate as follows. A radioscopy test is implemented in which x-rays with a defined radiation dose are generated by an x-ray source, the x-rays traversing the predetermined volume segment and strike a detector, and an intensity of the x-rays striking the detector is determined. A first radiation dose of x-rays is calculated to create a two-dimensional exposure depending on the determined radiation dose and the intensity. A second radiation doses of x-rays is calculated to implement a tomosynthesis depending on the determined radiation dose and the intensity. A tomosynthesis of the predetermined volume segment is implemented with x-rays that traverse the predetermined volume segment and strike the detector, the x-rays being generated by an x-ray source with the second radiation doses.