An illumination device emits light toward a moving subject. A controller controls light emitted from the illumination device so that the amount of light applied to the subject is adjusted to a specific amount or smaller. For example, when the illumination device emits light in a pulsed manner, the controller may control the amount of light applied to the subject by controlling at least one of the pulse width and the pulse intensity of the light. The controller may, for example, control the light emitted from the illumination device according to the distance between the illumination device and the subject.