An X-ray optical transmission grating of a focus-detector arrangement of an X-ray apparatus is disclosed, for generating projective or tomographic phase contrast recordings of a subject. In at least one embodiment, the grating includes a multiplicity of grating bars and grating gaps arranged periodically on at least one surface of at least one wafer, wherein the X-ray optical transmission grating includes at least two sub-gratings arranged in direct succession in the beam direction.