Imaging device and camera

A camera body includes an imaging unit, a reflecting mirror, a determination unit, and a mirror controller. The imaging unit is configured to convert the optical image into an image signal and acquires an image of the subject. The reflecting mirror has a first state of being in the optical path of the optical system and a second state of being outside the optical path. The mirror controller is configured to retract the reflecting mirror to outside the optical path of the optical system when the reflecting mirror is in the first state of being in the optical path of the optical system and a moving picture photography mode is selected, which is a mode for capturing moving pictures.