SA 47mm f8 v. 47mm f5.6 - Coverage???

Discussion in 'Medium Format Cameras and Accessories' started by RobertEM, Jun 10, 2010.

  1. RobertEM

    RobertEM Member

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    I am a little confused here. (Schneider links included below for both lenses for those curious.)

    The f8 is recommended for 65x90. The f5.6 is recommended for 60x60. Huh??
    Image circles differ by around 10 mm. Angles of view comparable. Is this a misprint maybe?

    I just purchased an f8 version, and had assumed the f5.6 would be sharper (owing to more glass/more complex optical design) AND cover a slightly larger diagonal.

    For practical purposes, I had thought the f5.6 did all that the f8 could - and more. Please help me clarify. Thanks!

    http://www.schneideroptics.com/info..._format_lenses/super-angulon/data/8-47mm.html

    http://www.schneiderkreuznach.com/archiv/pdf/an_su_1995.pdf
     
  2. ic-racer

    ic-racer Member

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    Maybe it is just that in the later literature 65x90 is just an odd format to 'recommend.' :smile:

    What camera are you going to use that on?
     
  3. Heinz

    Heinz Subscriber

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    I do use the SA 47mm f8 on my Linhof Super Technika 6x9. While it covers the "ideal format" 56mm x 72mm sufficiently

    http://www.apug.org/gallery1/showimage.php?i=52321&c=2

    it shows some vignetting on the polaroid back with 85mm x 73mm exposed area

    http://www.apug.org/gallery1/showimage.php?i=52170&c=2

    As I understood the image circle of the f5.6 should be slightly larger. In the links you cite one can compare
    image circle for 47mm f8: 113mm at f=16
    image circle for 47 mm f5,6: 166mm at f=22, 110mm at f=5.6.

    So in my opinion the 47mm f5.6 should have a larger image circle at correspondings f-stops.
     
  4. RobertEM

    RobertEM Member

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    ic-racer,
    My camera is a 50's era 35mm 'stereo' camera modified to produce a 35mm negative 24x96. Its kind of a pet project and an attempt to improve upon x-pan (24x65). Ha, ha! I kind of fell in love with my former format (7x17 - inches) but gave up on that. Lenses that will cover 6x9 cover the diagonal of 24x96 nicely (like the 47f8). I am now building a bellows for the 2496 and teaching myself as I go along. Also trying to design a tilting front standard for it. I love that all aspects of the camera have to be planned and designed. Lots of fun. Thanks for asking.

    Heinz - your comments are informative and appreciated. You now have me questioning whether I read the Schneider data pages correctly. BTW, the camera I modified was a German camera and very well made - Wirgin Edixa. Thanks!