To enable light emission shooting according to the condition of an imaging apparatus, an imaging system, which includes an illumination device capable of automatically driving a movable portion including a light emission unit to change a radiation direction of the light emission unit and an imaging apparatus, includes an acquisition unit configured to acquire information classifying a lens unit attached to the imaging apparatus, and a control unit configured to control the radiation direction of the light emission unit based on the information classifying the lens unit acquired by the acquisition unit.