shutter to lensboard mounting suggestions

**tim atherton** · 22-Oct-2005, 12:27

I'm mounting my Gundlach 7" wide angle to a technika type (Wista) lensboard.

Problem is the when the retaining ring is snugged down tight on the Alphax #3 shutter, the remaining gap is greater than the thickness of the metal lensboard so the lens/shutter can just rotate around (and it isn't exaclty light tight..)

So, any heath robinson suggestions for filling that gap? Right now I'm using a spare rubber washer from my espresso maker - but it's not really ideal - among other thigns, the differences in thickness isn't that great (hard to measure right now with the washer in - somwhwere between 1/32" and 1/16"?) and the rubber is almost too thick - I really have to snug the retaining ring down to get it on.

**N Dhananjay** · 22-Oct-2005, 12:34

I've used gasket material you can pick up at a hardware/auto supply store and made rings from them and that worked well. Cheers, DJ

**Conrad Hoffman** · 22-Oct-2005, 13:17

After you get your gasket material, mat board, thin plastic sheet, or whatever, mount an X-acto knife in a compass. Cut the OD first, then the ID, for a nice neat job. Is the problem by any chance related to a stepped retaining ring? If so, sometimes you can just flip it over.

**John_4185** · 22-Oct-2005, 15:35

Oh heck, a couple pieces of poster board cut round to fit will work just fine. Once you get it mounted, then use the exacto knife to trim while the lens is in-place, using the jam-ring as guide. A little Testor's flat-black paint at the very edges where the board shows will finish it all up.

If the lens is pretty tight, then it is light tight. If it is tight and still turns, then refer to the threads in which people suggest that everyone just throw away the locating pin that obviates the problem. Too late.

**tim atherton** · 22-Oct-2005, 15:40

"If it is tight and
still turns, then refer to the threads in which people suggest that
everyone just throw away the locating pin that obviates the problem."

that part of the problem - has a tendency to ratate - but as for the locating pin - no such beast on these puppies

**John_4185** · 22-Oct-2005, 18:59

that part of the problem - has a tendency to ratate - but as for the locating pin - no such beast on these puppies

Argh! I hate it when that happens. Well, it's one less thing to lose.

**Jon Wilson** · 22-Oct-2005, 20:55

You might try the plumbing o-rings. I find they help with a tachihara lensboard in obtaining a tight fit. This lens, as you know has a small thread area for attaching the retaining ring, but I believe this approach will still work. The o-rings work on my Tachihara boards, although my 7 1/4" Radar Ext. WA lens is presently front mounted on a deardorff board.