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rknewcomb
22-Jun-2010, 07:19
Does anyone know if the 110mm lensboards for an early Arca A/B camera have a notch at the top of them? Since my camera has not arrived yet I'm not sure how the lensboards attach. One I've seen had a notch at the top of the lensboard but I don't know if this is correct or not.
Any information about lensboards is appreciated and of course lensboards are welcome too.
thanks!

Sascha Welter
23-Jun-2010, 01:03
Mine definitely have some kind of notch thing. It's not used for anything though, I can insert them in any orientation. In fact in the beginning I was afraid the notch would lead to light leaks, but no, it's fine.

I can take a picture this evening (in about 8 hours) if you want to.

Emmanuel BIGLER
23-Jun-2010, 04:13
Hello from France !
I have both types of A/S Oschwald lens boards, with notch and without notch. I agree that the notch is probably not critical.
Beware however that older A/S Oschald lens boards are slightly smaller than "modern", "post-1984" F-line boards.
The older, "pre-1984" A/S Oschwald boards are 109x109 mm, whereas modern F-line are 110x110. It is not possible without modification to properly fit a modern F-line 110 board to an older A/S Oschwald 109mm standard.
However, in older A/S cameras, there are foam light seals, hence the board itself can be a simple flat board which is relatively easy to re-fabricate.
Modern 110mm F-line boards demand a precise adjustement to be light-tight but they do not rely on any foam.
Another remark if you need to re-fabricate a #1 lens board : beware that for some obscure reasons unknown to me, the range of thicknesses allowed for a #1 board is narrower than for a #0 board.
For a #1 board, board thickness should be between 1.5 and 3 mm whereas a #0 board allows up to 4 mm thick.
But this detail is probably irrelevant for an A/S Oschwald home-made board of, say 2mm thickness everywhere.
Simply, do not use something 4 mm thick at the center for a #1 board.
This is a general rule for #1 shutters, and not specific to any camera.

rknewcomb
23-Jun-2010, 05:28
WOW, now you understand why I asked the questions. I wonder why they put a notch in some and not in others and then allow you mount the board in any direction? That is odd isn't it!
Thank you for the input on board thickness - I would never have guessed that.

At least in pictures, I have seen some modern? 110mm boards with no ridges around the inside. I had thought maybe I could just file the outside down to the 109mm and it would work on my old model C 69 camera. But, maybe not.

I would love to see a picture of a "real" board if you don't mind.

Thank you!!

Robert

Emmanuel BIGLER
23-Jun-2010, 10:14
I would love to see a picture of a "real" board if you don't mind.

You can see a 109x109 A/S Oschwald board in front of this 6x9 A/S Reflex camera (a rarity)
http://www.cameramate.com/images/8178-1.jpg

It is hard to see whether there is a notch or not...
Looks like a plain, flat board on the image.

Sascha Welter
23-Jun-2010, 13:24
Here is a picture taken with a dumb digicam just now:

http://betabug.ch/ouzo/water/arca/arca_top_notch.jpg

That darker border seen in the corner next to the notch is probably some residue from the foam, since lately I put the lensboard backward into the camera during transport. It shows that the notch really shouldn't lead to light leaks.

As for why they made the notch and then the camera doesn't need it: I always assumed that some even older models of the camera had a mechanism to grip into the notch... but unlike Emmanuel I don't have any data to back that thought up.

rknewcomb
23-Jun-2010, 16:57
Isn't that odd looking!
Clever of you about putting the lens inside the camera for transport.
At least now I know what the boards look like.
I thank you for all the information.
Robert

Sascha Welter
24-Jun-2010, 00:48
Well, I don't think it's really so clever to put the lens into the camera for transport. I always fear a bit about something moving around and the lens smacking the groundglass. The story is that when I got my camera bag my 180mm Tele-Xenar had a stuck shutter, so it stayed at home. Now that the shutter is working again, I "unfortunately" have to fit 3 lenses instead of 2 inside the camera bag. Putting one of the lenses into the camera made for a little bit of extra space economy.

rknewcomb
29-Jun-2010, 10:52
As for why they made the notch and then the camera doesn't need it: I always assumed that some even older models of the camera had a mechanism to grip into the notch... but unlike Emmanuel I don't have any data to back that thought up.

I found this picture of an Arca Reflex camera. Looks like maybe this is where the notched board mounting is used.


/Users/robert/Desktop/arcaboard2.jpg

RK_LFteacher
2-Jul-2010, 17:10
This board and mount was a side sliding latch on very early Arcas.
So you mounted the board at the bottom and tipped it back and slid the latch to the side to lock in place.
Rod