5/8" extension on Beseler lensboard?

Discussion in 'Enlarging' started by eric, Oct 28, 2006.

  1. eric

    eric Member

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    Why is there a product with a 5/8" extension on a Beseler lensboard? It says its for a 105 and 135mm. I have a 105mm and it seems fine. I just got a 135mm lens and was wondering if I need a regular lensboard or a 5/8" extension lensboard.
     
  2. Nick Zentena

    Nick Zentena Member

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    For reductions? You got a model number for that board?
     
  3. eric

    eric Member

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  4. Nick Zentena

    Nick Zentena Member

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    I bet it's mostly aimed at the 23 model more then the 4x5s.
     
  5. eric

    eric Member

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    I sort of found something on the innernet (so it must be true right? ) that the extension is used for some lenses that have a large rear element. So I'm guessing, that some o fthe bigger lenses with 39mm thread, have that feature. I think you are right though, on the 23c, the focus rail stops short.
    So let say that I won this on the auction site cheap, I put my 135mm on it, and use it for 4x5 negs, perfectly okay right? I just need to raise the enlarger 5/8" inch more I guess.
     
  6. Nick Zentena

    Nick Zentena Member

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    Only problem would be when you want to make a max size enlargement. You'll be giving up some size at the top end. But if you aren't making 24x24 [or whatever the top size is] I doubt you'll notice.
     
  7. Nick Zentena

    Nick Zentena Member

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    Actually I take that back. Considering you can focus a 50mm with a flat board the extension won't matter even with a max enlargement.
     
  8. eric

    eric Member

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    Doesn't everyone make 24x24?
    I can barely make a nice 8x10 :smile:
     
  9. Pragmatist

    Pragmatist Member

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    You will find one also that is recessed...