Heligon

Discussion in 'Medium Format Cameras and Accessories' started by fpjohn, Dec 11, 2006.

  1. fpjohn

    fpjohn Member

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    Hello:

    Is there some secret source of data for older Rodenstock lenses? Specifically, what is the image circle of a 95mm F2.8 Heligon? Is it somewhere between that of a 100mm Planar and a Xenotar?
    yours
    Frank
     
  2. Dan Fromm

    Dan Fromm Member

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    Since the 95/2.8 Heligon was sold to be used with 2x3 backs on the Graflex XL, you should be able to count on 100 mm. Remember that the XL allows no movements.

    I have a similar 6/4 double Gauss type 95/2.8 Saphir that Boyer claims covers 105 mm. Perhaps, but if so, just barely.
     
  3. fpjohn

    fpjohn Member

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    Hello:

    A quick test (f11,infinity focus)) reveals crisp coverage out to 115mm and visible falloff at 120mm.

    yours
    Frank
     
  4. Tom Hoskinson

    Tom Hoskinson Member

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    Thanks for the info, Frank. I haven't gotten around to checking my Heligon. Looks like your Heligon will cover 6x9cm but not a 6x12cm.
     
  5. fpjohn

    fpjohn Member

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    Hello:

    I will, as a Holiday exercise, check performance over a full range of f stops.

    yours
    Frank
     
  6. Tom Hoskinson

    Tom Hoskinson Member

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    Excellent, Frank!
     
  7. fpjohn

    fpjohn Member

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    Hello:

    The Heligon f2.8 95mm gave soft images at f2.8 with falloff seen at 115mm. The image remains soft at f5.6 with reduced falloff from 115 to 120mm. The image becomes crisp at f8 with reduced falloff beyond 115mm. F8 and f11 yield crisp images with slight falloff at 120mm. The image remains crisp to the edges without falloff at f16 and f22.

    Polaroid 665 (72mm x 95mm) images, taken at infinity with an AR 6x9 on a tripod, were examined with a 3x Schneider loupe.

    yours
    Frank
     
    Last edited by a moderator: Dec 16, 2006
  8. jimgalli

    jimgalli Subscriber

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    There are Heligon's and Heligon's. I've got some that were apparently made for nocturnal 2/3 chip video. 75mm f1.1 with a teensy image circle. I see folks on other forums are adapting them to DSLR's and doing wild close in Bokeh at f1.1 and less. Some are f0.95 iirc.
     
  9. Dan Fromm

    Dan Fromm Member

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    There are faster ones still, Jim, used in X-ray machines. Fixed aperture doorstops, very hard to use for much. But fascinatin' none the less.

    Probably the most abundant are the 50/2s made for Retina IIs and IIIs. Anti-Xenons. I used to have a Retina II (sorry, don't remember which version) with a 50/2 Heligon that was a very useful little camera.
     
  10. fpjohn

    fpjohn Member

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