A focus/detector system of an X-ray apparatus and a method for generating projective or tomographic phase contrast recordings, are disclosed. In an embodiment of the system, the system includes a beam source equipped with a focus and a focus-side source grating, arranged in the beam path and generates a field of ray-wise coherent X-rays, a grating/detector arrangement having a phase grating and grating lines arranged parallel to the source grating for generating an interference pattern, and a detector having a multiplicity of detector elements arranged flat for measuring the position-dependent radiation intensity behind the phase grating. Finally, the detector elements are formed by a multiplicity of elongate scintillation strips, which are aligned parallel to the grating lines of the phase grating and have a small period, whose integer multiple corresponds to the average large period of the interference pattern which is formed by the phase grating.