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Thread: Wollensak 6 1/4" infinity focus

  1. #1

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    Wollensak 6 1/4" infinity focus

    I have a Wollensak 6 1/4" lens on an 8x10 camera and according to what I have read the lens should focus at infinity approx 6 1/4" from the ground glass. I am trying to accurately calculate bellows factor and the infinity focus on this lens is about 5 1/4" from the ground glass. I surmise I should use this distance for base exposure and calculate the bellows factor from there?

    Thanks, J

    joe murray | nativesonsfilms.com
    Directors Guild Of America-Director
    Int'l Cinematographers Guild -Director of Photography

  2. #2
    Big Negs Rock!
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    Re: Wollensak 6 1/4" infinity focus

    Depending on the lens design, your 5 1/4" could be accurate. And, like you said, I'd base my bellows factor on the 5 1/4" base.

    Enjoy your shooting.

    Mark
    Mark Woods

    Large Format B&W
    Cinematography Mentor at the American Film Institute
    Past President of the Pasadena Society of Artists
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    www.markwoods.com

  3. #3
    Mark Sawyer's Avatar
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    Re: Wollensak 6 1/4" infinity focus

    When in doubt, just figure your f/stop from scratch. It's just a ratio. But I can't imagine why you'd use that lens to shoot close enough to require bellows extension factoring...
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

  4. #4

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    Re: Wollensak 6 1/4" infinity focus

    Probably not the case, but it needs to be asked: are you measuring from the center of the lens, where you should be, or from the irrelevant back of the lens?
    Thanks, but I'd rather just watch:
    Large format: http://flickr.com/michaeldarnton
    Mostly 35mm: http://flickr.com/mdarnton
    You want digital, color, etc?: http://www.flickr.com/photos/stradofear

  5. #5

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    Jan 2018
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    Re: Wollensak 6 1/4" infinity focus

    I'm measuring from the optical center. When doing a foot to toe portrait there is about 7-7.5 inches of bellows ext and that would require about 1 stop of exposure compensation.

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