A camera system includes an interchangeable lens and a camera body. The interchangeable lens has a focal adjuster including a focus lens group, an absolute position detector configured to detect the position of the focus lens group with respect to a movable range, and a relative position detector configured to detect the movement amount of the focus lens group. The camera body has a first focal detector configured to detect the focal state on the basis of a contrast value and a second focal detector configured to detect the focal state by phase difference detection method on the basis of the optical image. When the first focal detector is used for focal adjustment, a detection of the focal state is performed on the basis of only the information obtained by the relative position detector.