An exchangeable lens mountable on a camera body includes: a selection unit configured to select a first state wherein a movement range of a focusing optical system changing the exchangeable lens' focal position is limited and a second state which is different from the first state, and a transmission unit configured to transmit a first and second value which is equal to or smaller than the first value to the camera body in the second state, the first value indicating a relationship between the focusing optical system's moving amount and an image plane's moving amount at a position wherein the focusing optical system has moved, the second value indicating a relationship between the moving amount of the focusing optical system and the moving amount of the image plane, and transmit a value which changes depending on the focusing optical system's position as the second value in the first state.