In a camera unit that is mountable to a lens unit having a focus lens, an AF signal processing unit generates an AF evaluation value from an imaging signal obtained by an imaging element, and a camera control unit generates drive information for moving the focus lens to an in-focus point using the AF evaluation value and transmits the drive information to the mounted lens unit. The camera control unit transmits drive information including a focus lens position served as a reference for micro vibration and an amount of movement of the focus lens indicated by shift amount of an image plane with reference to the focus lens position to a lens unit.