There are provided a camera system and an interchangeable lens that are compatible with a contrast detection method. A camera system (1) has an interchangeable lens unit (2) and a camera body (3). A lens microcomputer (40) changes the movable range of a second lens group (L2) via a focus lens drive controller (41) depending on whether a second holder (61) is driven by the focus lens drive controller (41) and a focus motor (80) on the basis of angle information inputted to a zoom ring (64) of the interchangeable lens unit (2), or the second holder (61) is driven by the focus lens drive controller (41) on the basis of contrast information.