Graflex.org

disemjg · Joined: 10 Jan 2002 Posts: 474 Location: Washington, DC

So I have now accumulated a number of Graphic press cameras, and have wondered about one rather odd detail on them. The lenses are mounted to the boards with a formed retaining ring that is shaped with a threaded body and a large flange which carries the spanner notches. If you saw the retaining ring unmounted you would assume that the flange would go towards the lensboard, to distribute the clamping force across a larger area. But all of them are mounted with the flange away from the board, using the narrow edge of the threaded body to hold the lens to the board. They must have had a reason to do it this way; does anyone have a clue why?

Les · Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI

If these are L-shaped in cross section the they were designed for the Anniversary Speeds with the wood lensboards, the threads would go beyond the rear surface of the board and the notched area would be up against the back of the board.

Most of the time I have seen these reversed so the flat and the notches are up against the board, but this way makes it easier to grab the ring.

Henry · Posted: Sat Dec 20, 2003 1:33 am Post subject:

Good question, often wondered about that myself. The only lens I have on a factory-mount/original-board set-up, the Graftar 103, has a retaining ring with an indexing slot in it to pass the head of a tiny screw that goes through the lensboard and into a threaded hole in the back of the shutter case. Presumably this "lock" is to prevent the lens from turning and the ring from loosening. The only way this can function as intended is if the wide flange is against the lensboard. But obviously the shutter will work either way you mount the retaining ring (also referred to as a "jam nut"), unless the hole is too big so the narrow flange can't grab metal.

I believe that my Graphex shutters also have the threaded hole to receive the tiny indexing screw. When you mount the lens on an after-market lensboard, you have the option of using the indexing feature if there's a corresponding slot in the jam nut. Of course then you have to locate and drill a small hole in the board, and this assumes that your shutter came with the tiny screw. Failing any of these, it may not be worth the effort. That's when you want the wide flange against the board, for the reason you stated.

Does any of this make sense?

45PSS · Posted: Sat Dec 20, 2003 3:31 am Post subject:

I have sceen factory drilled lens boards where the lens barrel was slightly smaller than the drilled hole and the outer edge of the mount ring just fit. With this configuration, the mount fing would go on narrow end first and when tightned would prevent the lens threads from touching the lens board preventing damage to board or lens. A lens threads are in danger of becoming mared on a metal board and a wooden board in danger of damage from the lens threads if the lens is loose and moves around. Graflex boards, on the other hand, are so thin as to invalidate any rule of thumb.

Chalres

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[ This Message was edited by: 45PSS on 2003-12-19 19:34 ]

jdman · Joined: 13 May 2001 Posts: 302 Location: Midwest

On the 2x3 crown and Centurys that I have the board has a divit to prevent the lens from turning. If you try to put the wide end down when installing the lens then, it will hit this divit first, and this will not work. Russ

Henry · Posted: Sat Dec 20, 2003 2:45 pm Post subject:

Well, I got off my fat lazy duff and went and actually took a look at my Graphex lens mounts. The head of the little indexing screw is in one of the slots for the spanner, not in a separate slot just for it. For this configuration to work as intended, the wide flange must be against the board.

What I find interesting in these posts is all the different variations! Just when you think you have it all together with this stuff, seemingly simple matters such as lens/board mounting comes along and you find out there's more than one way get results!

davebias · Joined: 20 Oct 2003 Posts: 43 Location: New York City

Like jdman, two of my boards have the divot, which is very close to the mounting hole so the retaining ring must go on fat-side-up to clear the divot.

For my purposes, having the fat-side-up makes it easier to get to the notches with a lens wrench and keeps me from scratching up the board.

The lens I got mounted at Lens and Repro recently has the fat side down, and it has to stay that way because the hole they drilled was just slightly bigger than the rear element of the lens. If I put the retaining ring on skinny side down, it goes right through that hole.

And while we're on the subject - is it "officially" a Jam Nut, a Retaining Ring, a Mounting Flange, or what? I would in fact favor all of us getting together and creating an entirely new word that's easier to type. Like maybe we could call it a "floggle" or something like that...

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disemjg · Joined: 10 Jan 2002 Posts: 474 Location: Washington, DC

The installation with the flange up is evidently how the factory intended it. In my collection are a half-dozen cameras that I am confident are original, and all of them are done this way. The factory had to keep good tolerances to keep the edge of the retaining ring from slipping through the hole. It is weird, but original. To see a ring installed flange down on a metal board is a sign of a problem such as an oversize hole. The screw on the back of the shutter, which I call an anti-rotation post, drops into a pocket formed in the board. The arrangement described above where the screw goes in through the board from behind is one I have not seen, and may not be original. On the wooden boards and on Super boards the flange is naturally mounted away from the shutter to accomodate the thickness of these boards.

Les · Joined: 09 May 2001 Posts: 2682 Location: Detroit, MI

The word 'flange' is used both inside and outside of the photo world to denote a large ring with smaller holes about it's diameter. So all of those brass lenses on wood board where the ring is screwed to the front of the board is a flange.

Since I prefer to [i]retain[i/] my lenses rather than [i]jam[i/] them onto something, I prefer the latter.

les

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"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

Henry · Posted: Sun Dec 21, 2003 2:52 am Post subject:

To "disemjg": right, the factory boards have the pocket (at least, that's the case with my factory-original Graftar mount), but the after-market boards I obtained don't have the pocket. That's how I came up with the idea to drill a small hole in the board next to the large one so the small screw head can serve as a locking index for the shutter. The alternative is to remove the small screw from the back of the shutter case and just rely on tightening down the jam nut/retaining ring to keep the lens from twisting in its hole. In either case I prefer to mount the shutter with the wide flange against the board. I don't use a spanner but just hand-tighten the shutter retaining ring. Works for me, YRMV!

Seasons Greetings,

Henry

[ This Message was edited by: Henry on 2003-12-20 18:53 ]