View Full Version : What is this screw for on my lens...?

25-Nov-2011, 21:44
I was trying to install my Schneider 120mm HM lens on a board today and noticed it wasn't sitting flush, I removed it from the board and saw this screw protruding which prevents the board from sitting flat (the flat head one in the black area):


I looked at a couple other of my Schneider lenses and there is a hole where that screw would be but there isn't a screw there (and the board sits flat). Whats up with that screw? Can I remove it, should it go in further, am I doing it wrong ? :)

Mark Stahlke
25-Nov-2011, 22:13
The screw is an anti-rotation pin. A few lensboards have a hole drilled for this pin. Most people just remove the screw and discard it.

25-Nov-2011, 22:29
Sweet, took it off. Thanks!


26-Nov-2011, 00:29
The purpose of the screw is to prevent the shutter from rotating and coming loose.

I've had this happen on shutters that were mounted without the screw.

You can cut or file a hole on the periphery of the lensboard hole, at 12 o'clock, about 1/8" diameter.

These used to be present on all shutters. Now the Copal #0 and #1 shutters have the tapped holes but the screw is not included with new shutters.

I always use the screws. Cheap insurance. Although a loose shutter won't fall off, it can have light leaks.

- Leigh