A lens-interchangeable camera system includes: an interchangeable lens unit storing lens characteristic data corresponding to parameters of lenses in a discrete manner; and a camera body unit to which the lens characteristic data is transmitted from the interchangeable lens unit when the interchangeable lens unit is mounted. The camera body unit includes an acquisition data storage unit storing the transmitted lens characteristic data, a closest data acquisition processing unit, a close data acquisition processing unit, and an unacquired data acquisition processing unit. Processing is performed in the order from the closest data acquisition processing unit, the close data acquisition processing unit and the unacquired data acquisition processing unit.