What you should see on the body flange looks like the tip of a small screwdriver blade. The part on the lens itself (on the mounting flange face) looks like the head of a screw. The blade tip part (in the camera body) inserts into the slot in the lens when you mount it. It turns like a screwdriver to operate the focusing mechanism in the lens, hence the nickname for the autofocusing system. You should never see threads unless you have taken the lens apart.
Mar 09, 2012 at 07:52 PM
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