A retractable lens barrel includes an annular ring having an axis parallel
to and eccentric relative to an optical axis of the lens barrel; a holder
accommodated within the annular ring and supporting a holder lens group;
a first lens group aligned with the optical axis and movable towards the
annular ring during accommodation of the first lens group within the
annular ring; a first actuator of an exposure control component, the
first actuator positioned inside the annular ring in a first space
between an inner peripheral surface of the annular ring and an outer edge
of the first lens group accommodated in the annular ring; and a second
actuator of the exposure control component, the second actuator being
positioned inside the annular ring in a second space between the inner
peripheral surface of the annular ring and the movement path of the
holder lens group.