Wonderful "new" source for flat-field macro lenses

Discussion in '35mm Cameras' started by Norm Dresner, Dec 23, 2005.

  1. Norm Dresner

    Norm Dresner Guest

    I recently purchased on eBay a Componon-S enlarging lens with the idea that
    I'd fit it to the bellows of my 2-1/4" sq camera as a flat field macro lens.
    While cleaning off a shelf I came across a T-mount for my Nikons and
    discovered that the enlarging lens' thread matches perfectly the inner
    thread of the T-mount. This means that any really good enlarging lens with
    standard thread can be mated with a T-mount for "any" 35mm camera and put on
    a bellows or extension tube to function as -- perhaps -- one of the finest
    flat field copy/macro lenses available.

    Norm
     
    Norm Dresner, Dec 23, 2005
    #1
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  2. Hi Norm

    It's just possible that the Componon will work better for high
    magnification if reversed - then the optics will be working at something
    like the cojugates it was designed for. Of course, if it is a
    symmetrical design, it may not make that much difference.

    My 50/2.8 and 100/5.6 Componons both have 43mm filter threads on the
    outside, so an adapter ring should be possible. The stop down lever
    might get in the way though.

    I haven't tried this with mine - I have numerous other purpose-built
    macro lenses already.

    David
     
    David Littlewood, Dec 23, 2005
    #2
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  3. And what is the colour rendering like ?
    I tried this years ago, but the huge difference between the colour from my
    Minolta camera lenses, and the 50mm f2.8 CE Rokkor enlarging lens meant that
    my results were only OK if I was using B&W. (This was before Photoshop...)
     
    Malcolm Stewart, Dec 23, 2005
    #3
  4. Norm Dresner

    Norm Dresner Guest

    I haven't tried using the lens yet, but should be able to get to it in the
    week between the holidays [How's that for PC mealymouthing to avoid using
    the word "Christmas"??? I apologize! <LOL>]

    Norm
     
    Norm Dresner, Dec 24, 2005
    #4
  5. Norm Dresner

    bjw Guest

    I'm assuming you mean a normal T mount that fits on the camera
    body and has a female thread to take T-accessories (lenses,
    telescope adaptors, etc). I'm surprised you can screw your enlarging
    lens into one, because the thread specs are different. The T-thread is
    42 x 0.75mm; recent Componon-S lenses in the 80-100mm range
    are Leica thread (39mm,26tpi), older ones are 25mm, and bigger
    ones are 50mm.

    I looked at a couple of T mounts and both had an inner thread behind
    the main thread, but neither was Leica thread, just some random
    threading the manufacturer put on to reduce reflections. Also it was
    impossible to actually fit the lens that far back into the mount.
    While it's great that you heve something that fits, be aware it may not
    work on the next T adapter you come across. That said, the basic
    idea of putting an enlarger lens on bellows is good; some makers
    may have made adapters, plus there's always the official method,
    namely gaffer taping a lensboard to the front of the bellows.
     
    bjw, Dec 31, 2005
    #5
  6. Norm Dresner

    Norm Dresner Guest

    I guess I wasn't looking all that closely when I discovered the match but
    since you've mentioned it, I did some more research. I went to the
    Schneider website and downloaded the spec sheet for the lens (135mm f/5.6)
    which includes a detailed drawing of the lens at
    http://www.schneideroptics.com/photography/photo_enlarging/componon-s/pdf/componon-s_56_135.pdf.

    The lens that I have seems to conform to that drawing as closely as I can
    measure it with an inch-based dial caliper EXCEPT that the drawing calls for
    a thread of 50mm x .75mm and the lens I have clearly has a thread that's
    significantly smaller! In fact it's 1.647" diameter which corresponds to
    42mm (actually 41.83 but that's close enough to 42mm for me -- and to the
    T-mount adapter too).

    AFAICT, this is a perfectly normal T-mount adapter designed to take a 42mm
    thread.

    SO ... the question is, why does this seemingly normal Componon-S lens have
    a 42mm thread where it should have a 50mm thread?

    The (non)answer, of course, is, "I don't know!"

    If anyone has more information that will shed light on this mystery we'd
    (all) be grateful.

    Norm
     
    Norm Dresner, Dec 31, 2005
    #6
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