beseler 23 C lens board/focusing

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I just bought a used beseler 23 C enlarger(blue) I also acquired a new lens board from B&H (39mm Lensboard with Mounted Flange) and a used nikkor 50mm 2.8. when I assemble everything I need to turn my focusing knob up to the top to focus my picture, wich totally compresses the belows and makes it hard for the enlarger to stay in focus. any idea of what I'm doing wrong, do I have the wrong lens board or is there a setting on the enlarger I need to change( it originately came with a 75mm lens). I'm a real novice but eager to learn, thanks for your lights on this, Christian.

-- christian haudenschild (cracra1@excite.com), December 04, 2001

Answers

is the lens board cup shaped and you have put it in backwards? My Saunders 670 is configured such that one lensboard will work with a 50mm and, when screwed in from the other side, an 80-100mm lens.

-- r (ricardospanks1@yahoo.com), December 04, 2001.

Christian, check and make sure your condenser is set to 35 mm, and also check to see if the condenser lenses are in correctly. Did you get a booklet with the enlarger?

chris

-- Christian Harkness (chris.harkness@eudoramail.com), December 04, 2001.


It sounds like you have a recessed lens board, or that you are trying to make a very large print. The lens board for a 50mm lens on this enlarger should be flat, allowing the lens to protrude below. If you have a flat board, try lowering the enlarger body and refocusing. To determine the largest enlargment you can make: Raise the lens as far as it will stay with the bellows moving it and then move the enlarger body up, or down, until the image is in focus. If I remember correctly, you should be able to get to 16x20, but not a full 20x24.

If this does not resolve your problem, provide a little more information about exactly what you have done and we will see if we can help you more.

-- Ed Farmer (photography2k@hotmail.com), December 04, 2001.


If the lensboard is flat, this is probably normal. The bellows will be quite compressed, and if the focusing mechanism is loose and the bellows a bit stiff, it will tend to move on its own. If that's the case, snap the back off the focusing mechanism box and tighten the tension screws slightly.

-- Conrad Hoffman (choffman@rpa.net), December 04, 2001.

Thanks all for your answers. so to answer some of the questions, yes my condenser is in 35mm position(fully at the top) but I have no booklet so I'm not quite sure if everything inside is how it should be(anyone has an idea how to get a manual? or scanned version or photocopied?) there are two large condenser lenses with the round face inward facing each other and flat on the outside. The enlarger came with a little paper enveloppe containing additional small glass condensers(approx 2 inch in diameter) but I don't know what to do with those or if they belong with this machine. Any idea anyone? my lens board look pretty flat with a hole and a premanently fixed ring inside the hole it is but very slightly recessed 2mm maybe, but I can't mount it backwards without removing the two large screws (holding aids?) on either side of the objective. I was trying at an 8X10 print size , when I go smaller it eases the problem a little. Does that clarify my case? Thanks for the active discussion I'm quite impressed by the quality and responsivitiy on this BB, Christian.

-- christian haudenschild (cracra1@excite.com), December 04, 2001.


Your problem seems chronic to 23C enlargers. It appears that a 50mm lens has to get so close to the negative that the 23C bellows just about goes hard, when a flat lensboard is used. My 23C did this for a time, but I was always able to achieve sharp focus, even though the bellows was pretty compressed. I put a spring clothespin or two on the rail under the lens assembly so the bellows couldn't force the lens down and out of focus. As the bellows aged, it was easier to compress, and I dispensed with the clothespins. Using a concave lens board would probably eliminate the problem.

-- Keith Nichols (knichols1@mindspring.com), December 04, 2001.

Christian, I thought I had a diagram, but I can't locate it. From your description it seems everything is ok. I have never run into this problem. I recommend you give Bessler a call.

chris

-- Christian Harkness (chris.harkness@eudoramail.com), December 05, 2001.


I don't have a Beseler enlarger, but I think I have access to a manual I can copy for you. Send me your e-mail address and the exact model you have, and I'll see what I can do.

-- Jim Rock (jameswrock@aol.com), December 05, 2001.

i have talked to beseler about this very problem it seems the 23c was designed to be used with a 40mm lens if you are doing large prints, you will need to get a lens board with flange. this will let you get the lens closer to the negative make sure the hole it is 39mm the only thing is, if you have the model with the sliding tray it,s probly going it hit the lens no big d just keep it out of the wa

-- (maxlove@ziplink.net), January 03, 2002.

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