HELP: Beseler 23C II Lens won't screw in

Discussion in 'Darkroom Developing and Printing' started by jephey, May 7, 2006.

  1. jephey

    jephey Guest

    I just got a second hand enlarger, and I noticed it came with a 75mm
    lens, I unscrewed the 50mm one that was loose to begin with (Too loose
    to adjust the aperture) and now the 75mm won't screw in. There is a
    metal ring in the (?) lens board (?) and it's loose. Nothing snapped,
    cracked broke etc. I don't know what to do.

    Thanks for reading,


    AIM: jephey
    jephey, May 7, 2006
    1. Advertisements

  2. jephey

    nathantw Guest

    The ring has the threads that hold the lens in place. Just reach into
    the negative area, hold the ring in place and screw the 75mm lens in
    place. Do the same with the 50mm.
    nathantw, May 7, 2006
    1. Advertisements

  3. If it is a standard Beselar lens board, the ring is not part of the lens
    board and if you turn it upside down, it should fall into your hand or onto
    the table.
    Jean-David Beyer, May 7, 2006
  4. jephey

    jephey Guest

    I had to take off the lens board and undo all the screws and hold the
    thread while I screwed the lens in. Thanks for the help. Is there any
    real difference between the 75mm and the 50mm?
    jephey, May 7, 2006
  5. Hmmm... Others answered your questions, so I'll *ask* a couple to
    start some conversation that might be educational!

    What film size are you planning on doing? The 50mm lense is for
    35mm negative. The 75mm lense is for larger negatives, and will
    only make small prints when used for a 35mm negative.

    But the real question is just exactly what are your two lenses?
    (The original lense supplied by Besler was, ahem... *horrible*.)

    The good news is that really top quality enlarging lenses are
    selling used today for peanuts. Hence if you have a poor lense
    or for that matter even a half decent one, it is easy to pick up
    a very good one.
    Floyd L. Davidson, May 7, 2006
  6. I can't remember now just exactly how the Besler 23 lense board
    works (haven't used one for 20 years), but generally the way
    people deal with changing lenses is to have each lense
    permanently mounted on a different board. The entire board +
    lense is swapped.

    Yes, there is a significant difference between 75mm and 50mm
    lenses. But first, which lenses do you have? And what size
    negatives are you going to work with?
    Floyd L. Davidson, May 7, 2006
  7. Argh. You shouldn't have to take out any screws to remove the
    lensboard. It's spring loaded; you angle it in against the rear spring,
    and press until the front edge will fit past the lip and stay in place.
    I hope you get it all put back together...
    Scott Schuckert, May 7, 2006

  8. How to make a simple task difficult and destroy your new enlarger all in one
    easy step. Follow Scott's comment. Do not disassemble the enlarger
    unnecessarily. Mosts tools are designed for easy operation. If you do not find
    the easy way, keep looking.

    Thanks for the help. Is there any

    25 mm. Seriously, the lenses are sized to the negatives they are intended to
    develop. (By the way, notice that the top rack and pinion bellows control has
    markings for the locations that you should stop at for negatives from 35 mm to 2
    1/4 x 3 1/4 inches. You have to adjust this for each lens that you use.) A 35
    mm negative is 24 mm x 36 mm and the diagonal distance is about 43.5 mm. So a
    50 mm lens is large enough with a little extra to "cover" the diameter of the
    negative when projected. A 75 mm lens is about appropriate on the same basis
    for a 2 1/4" x 2 1/4" negative, which is about 56 mm to a side. (SQRT [56^2 +
    56^2] = 79 mm.) In fact, some people prefer a slightly larger lengs for the
    job. I often use a 90 mm lens for a negative this size. To complete the
    analysis for the lenses available for the Beseler 23C, (1) a 90 mm lens is
    required for a 6 x 7 negative (nominally 60 mm x 70 mm or 2 1/4" x 2 3/4"), the
    negative is about 56 mm x 65 mm, yielding a diagonal of 86 mm; (2) a 105 mm lens
    is required for a 6 x 9 (aka 2 1/4" x 3 1/4") negative, with a diagonal of 102
    mm (SQRT [56^2 + 85^2].

    Francis A. Miniter
    Francis A. Miniter, May 7, 2006
  9. Lenses for most enlargers use the standard Leica thread on the mounting
    flange. Of course, Leica don't use it on their cameras anymore. As
    others have said, the lensboard for the Beseler can be as simple as a
    piece of 1/8 " plywood with a 40 mm hole cut in the middle if you have
    the retaining ring. I used to get 1/8" plywood at hobby shops.
    PATRICK GAINER, May 7, 2006
  10. I made several by laminating cardboard from the back of legal
    pads with contact cement.

    Flat Omega lensboards can be made from scrap printed circuit
    board material with something to give thickness for mounting the
    I make the hole in each sheet of cardboard as a hexagon before
    laminating. The cutouts are slightly undersize and 'rotated'
    from each other. Screw the lens straight into the cardboard.

    For blacking cardboard/foam core/AOS* I use Black Kiwi
    "Edge Dressing" [for putting a nice black finish on the edge
    of the sole of one's Lobb's] it dries water insoluble
    and will even stick to polyethylene.

    I paint the cardboard with varnish/shellac if I want to
    make the lensboard semi-permanent.

    I have made temporary lensboards for Sinars, Graphics and
    Centuries this way. Sometimes a bit of electrical tape is
    needed for a good light seal if used on a camera.

    Temporary lensboards are neat for fooling around: reversed
    enlarging lenses for macro work with an 8x10; pin-holes;
    home-made 'portrait lenses' made from one or two close-up
    lenses and an orange juice can; anamorphic slit pinholes;
    pinhole and close-up lens combinations...
    Nicholas O. Lindan, May 7, 2006
  11. PATRICK GAINER spake thus:
    1/8" masonite is much easier to obtain anywhere in the "civilized" world
    and works just as well.

    Pierre, mon ami. Jetez encore un Scientologiste
    dans le baquet d'acide.

    - from a posting in alt.religion.scientology titled
    "France recommends dissolving Scientologists"
    David Nebenzahl, May 7, 2006
  12. jephey

    John Guest

    Might find this helpful in the future :

    John S. Douglas
    Photographer & Webmaster
    John, May 8, 2006
  13. jephey

    BertS Guest

    25 mm?
    BertS, May 30, 2006
  14. jephey

    Mike King Guest

    MOST 50mm lenses are intended for 35mm (24x36mm) and will give greater
    magnification for a given enlarger height than a 75mm lens.

    MOST 75mm lenses are intended for 6x6 negatives (60x60mm) and will give less
    magnification for any given enlarger height, usually not an issue since you
    are using a larger negative.
    Mike King, Jun 1, 2006
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.