The present invention relates to grating based Dark-Field and/or phase-contrast X-ray imaging. In order to improve the quality of an image, a radiography system (10) for grating based Dark-Field and/or phase-contrast X-ray imaging for imaging a patient by irradiating the patient is provided. The system comprises a source unit (12), a detection unit (14) and a patient support unit (16) with a patient abutting surface (18). The source unit (12) and the detection unit (14) are arranged along an optical axis (13) and the patient support unit (16) is arranged in between. Further, an abutting distance (dA) between the source unit (12) and the patient abutting surface (18) along the optical axis (13) is adaptable. The abutting distance (dA) and an actual sensitivity, based on the abutting distance (dA), are taken into account for imaging, such that a trade-off between sensitivity and field of view in a patient specific manner is achievable, e.g. the best trade-off.
