An imaging apparatus includes a control unit and a detector that includes multiple pixels and that performs an image capturing operation to output image data corresponding to radiation or light that is emitted. The image capturing operation includes a first image capturing operation in a first scanning area corresponding to part of the multiple pixels to output image data in the first scanning area and a second image capturing operation in a second scanning area larger than the first scanning area to output image data in the second scanning area. The control unit causes the detector to perform an accumulation operation in the second image capturing operation in a time determined so that an image artifact caused by the scanning area is lower than a predetermined allowable value on the basis of information about the amount of integration of accumulation times in the first image capturing operation.