A lens barrel is provided that includes a zoom optical system, a zooming unit, and a light adjusting mechanism. The zoom optical system is configured to form an optical image of a subject and includes a first, a second, and a third lens group. The third lens group is movable and configured to move the optical image. The zooming unit causes the zoom optical system to perform a zooming operation. The light adjusting mechanism is configured to adjust the light passing through the zoom optical system. The lens barrel is configured to change between an imaging state and a retracted state. In the imaging state, the zooming operation is performed, and the first, the second, and the third lens groups are in alignment. During the zooming operation, the second lens group moves integrally with the third lens group along the optical axis, and the light adjusting mechanism and the second lens group move independently of one another along the same axial direction. In the retracted state, the second lens group is disposed off center from the first lens group.