An optical image of a subject is acquired with a camera while the subject is disposed between a radiation output device housing at least two radiation sources and a radiation detecting device. Doses of radiation to be emitted from the at least two radiation sources are weighted based on the optical image, and weighted doses of radiation are applied from the at least two radiation sources to the subject. A radiographic image of the subject is acquired by detecting radiation that has passed through the subject with the radiation detecting device.
