PROBLEM TO BE SOLVED: To provide X-ray imaging systems that permits proper exposure timing control or exposure amount control while avoiding drawbacks in the prior art such as excessive exposure or insufficient exposure caused by wrong alignment of radiation source and a subject.SOLUTION: The radiography system (10) allows for user determination of a region of interest (56) on the subject prior to X-ray exposure. The region of interest (56) is defined by user interaction with an image (52), a pointer system (50), or the like. The region of interest is then translated (62) to the imaging coordinate system, such as in the plane of a digital detector (24). The region is then used for exposure control during an imaging sequence, either in an open or closed-loop manner.