Assertion: diaphragm's aperture | /r/AtLocation | separate diaphragm
Facets:
Source sentences:
text: The single and double bladed ones just move up and down (or round and back for rotary ones) across the aperture contained in a separate diaphragm, but the multiple-bladed leaf shutters, especially with the introduction of curved ends to the blades, were now able to form a near-cicular hole as they opened and then closed again (as a shutter must do).