the back side of the copal #0 shutter on my nikkor sw 90/8 (the surface which rests immediately adjacent to the lens board) is presenting an odd problem in mounting the lens. on the back side of the shutter, you can see the control ring for the aperture adjustment. this ring is held in place by a smaller ring with three small screws - this smaller ring also serves to offset the lens from the lens board by a small amount to allow for movement of the aperture adjustment. however, also present in this outer ring is a small set screw which extends out from the ring and will not allow me to mount the lens flush with the lens board. what is this set screw for, and why does it stick out like this? what is the solution? thanks.

-- jnorman (jnorman@teleport.com), September 03, 1999

Answers

This is an alignment screw. For the seriously anal, you drill a small depression (but not a hole) in your lensboard, just deep enough to accomadate the screw head. This stops any slippage even if your locking ring loosens. In my view the sensible thing to do is (a) unscrew it (b) throw it away (c) mount to the lensboard in the normal fashion. It serves no other function in retaining any part of the lens mounting.

-- Mark Eban (markeban@compuserve.com), September 03, 1999.

Right, the salesman at Yodobashi Camera told me it was because the Nikon lens boards have the alignment hole pre-drilled.

-- James Chow (jchow@isl.melco.co.jp), September 07, 1999.