US Patent 7467900 Camera body, interchangeable lens, and camera system

At least one exemplary embodiment is directed to an interchangeable lens that can be connected to a new type camera and also to an old type camera, for example by requesting a release lock or not requesting a release lock, can be provided with a camera determination unit and a failure determination unit. Further, a camera body can be provided with an interchangeable lens determination unit, which can be set by a user so that an information request is ignored if an old type lens transmits a request for the release lock, where in the case of a new type lens, the camera body can perform a failure information communication with the lens, and an operation of the camera can be changed in accordance with the failure.