A radiation imaging system includes an imaging apparatus, an obtainment unit configured to obtain a usage mode of the imaging apparatus, a control unit configured to control the imaging apparatus to generate a radiation image and offset data, and an image processing unit configured to correct the radiation image by using the offset data. The control unit determines, based on a capability to suppress a temporal change of offset data according to the usage mode, whether to cause the imaging apparatus to generate the offset data between a start of imaging preparation and a start of radiation emission.
