X‐ray phase imaging including phase tomography has been attracting increasing attention during the past few decades. The advantage of X‐ray phase imaging is that an extremely high sensitivity is achieved for weakly absorbing materials, such as biological soft tissues, which generate a poor contrast by conventional schemes. Especially for such living samples, where the reduction of the applied dose is of paramount interest, phase sensitive measurements schemes have an inherent potential for a significant dose reduction combined with an image quality enhancement. Several methods have been invented for x‐ray phase contrast imaging that either use an approach based on interferometry, diffraction or wave‐field propagation. Some of these techniques have a potential for commercial applications, such as in medicine, non‐destructive testing, security and inspection. The scope of this manuscript thus deals with one particular such technique that measures the diffraction caused by the specimen by means of a grating ...