When a wheel is rotated, first inclined portions of end surface cams provided
on the wheel push corresponding cam followers formed on a movable cylinder. Accordingly,
the movable cylinder holding a photographing lens is extended. Then, when each
of the cam followers reaches a first flat portion of the corresponding end surface
cam, the movable cylinder is placed in a photographing position. In the photographing
position, when the wheel is further rotated, the cam follower is pushed by a second
inclined portion of the end surface cam. The movable cylinder is thus extended.
Then, when the cam follower reaches a second flat portion of the corresponding
end surface cam, the movable cylinder is placed in a macro photographing position.