olyacme Offline Upload & Sell: Off
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dereksurfs wrote:
But the thing I don't understand are the metal push buttons and how these are tied to stopping down? So does one really need to hold these buttons down while stopping down? How is this supposed to work? When I turn the aperture ring alone it doesn't appear to do anything. The lenses diaphram only closes when I push the buttons. Is that 'normal' or could my aperture ring control be broken?
One button is the lens release, the other is the DOF preview. Depressing the DOF preview button is more or less the same as activating the aperture stop-down lever on the rear of the lens. On typical adaptors, a small arm holds the stop-down lever fully actuated at all times, mooting the DOF preview button. Some shooters prefer an adaptor without that arm, and manually depress the DOF preview button just before shooting. This allows them to focus while the lens is wide open, without turning the aperture ring back and forth all the time. On an OM camera, of course, the lens would normally be wide open, and stop automatically for exposure.
Upshot: your lens sounds healthy, though if it doesn't stop down when attached to an adaptor then perhaps you have one of the armless types. At $100 you've probably gotten a great deal.
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