A shutter for an optical apparatus has multiple sectors and an operation
member. Each of the multiple sectors has a cam opening for engagement and
is pivotally provided to open and close a shutter opening, the operation
member moves each of said multiple sectors in engagement with the cam
opening, and the cam opening of at least one sector that is one of the
multiple sectors is formed to change a moving direction of said at least
one sector, when the operation member moves said at least one sector to a
position to close the shutter opening.