A normally closed shutter in a camera has at least one blade that is moved to open and close the shutter. A movable blade-driver in the camera has a supporting connection with a fixed support to support the blade-driver for movement, and has a driving connection with the shutter to drive at least the one blade to open and close the shutter when the driver is moved. A fixed blocking ramp in the way of the blade-driver stops the blade-driver once the blade-driver has moved to drive at least the one blade to close the shutter. The fixed ramp is inclined to urge or cam the blade-driver to create a high friction-type force at the supporting connection that impedes movement of the blade-driver to drive at least the one blade to re-open the shutter, whereby the shutter is prevented from being reopened unintentionally.