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Thread: 1800mm APO Nikkor

  1. #21

    Join Date
    Feb 2006
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    Re: 1800mm APO Nikkor

    What lens is that? With two, one could do stereos.
    One man's Mede is another man's Persian.

  2. #22

    Re: 1800mm APO Nikkor

    1800mm f16 Rodenstock Apo-Ronar. Used for this: http://www.immediatus.de/NINE_txt.html

    In action: http://www.notizie.it/wp-content/blo...1/09/wirtz.jpg

  3. #23

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    Re: 1800mm APO Nikkor

    Quote Originally Posted by Ken Lee View Post
    A friend sent me a photo of an 1800mm APO Nikkor that he rescued from a company which made aerial maps. He says that for 1:1 copying, the bellows draw was 11.8 feet, namely twice the normal infinity extension of 1.8 meters.
    So if this one is an "ordinary" Tessar, how does it explain the 3.6m (instead of 1.8m) bellows draw for 1:1?

  4. #24

    Join Date
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    Re: 1800mm APO Nikkor

    Quote Originally Posted by genotypewriter View Post
    So if this one is an "ordinary" Tessar, how does it explain the 3.6m (instead of 1.8m) bellows draw for 1:1?
    When we say a lens is 1800mm, we mean that it requires 1800mm when focused at infinity. The exception are telephoto designs, whose optical designs allow them to require shorter bellows draw than normal. Lenses designed for SLR cameras sometimes require longer bellows draw than normal, in order to accommodate the mirror inside the camera.

    For a normal lens (not retrofocus), a 1:1 photo requires 2x the infinity bellows draw. A 120mm macro lens will require 240mm at 1:1.

    M = (b-f)/f

    where M = magnification ratio, b = bellows extension, f = focal length

    How about a 210mm lens where the magnification is around 1:3. We can calculate the required bellows draw using the following formula:

    Here M = 1/3, f = 210mm, and b is unknown

    1/3 = (b-210)/210
    1/3 * 210 = b - 210
    70 = b - 210
    b = 280mm

    So a 210mm lens will require 280mm of extension to make an image at 1:3 magnification.

    For 1:1

    1 = (b-210)/210
    210 = b-210
    420 = b

    So a 210mm lens will require 420mm of extension to make an image at 1:1 magnification.

  5. #25
    ic-racer's Avatar
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    Feb 2007
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    Re: 1800mm APO Nikkor

    Quote Originally Posted by genotypewriter View Post
    So if this one is an "ordinary" Tessar, how does it explain the 3.6m (instead of 1.8m) bellows draw for 1:1?
    1.8 x 2 = 3.6

  6. #26

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    Re: 1800mm APO Nikkor

    This typically happens at 1.45am...

  7. #27

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    Re: 1800mm APO Nikkor

    It looks like the lens used by Ian Ruhter here (with maybe a different FL):
    http://player.vimeo.com/video/39578584

  8. #28

    Re: 1800mm APO Nikkor

    people say this lens doesn't exist but it does and it is huge.

  9. #29
    Hack Pawlowski6132's Avatar
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    Re: 1800mm APO Nikkor

    Quote Originally Posted by FrostySnaps View Post
    people say this lens doesn't exist but it does and it is huge.
    Why would anyone use this?

  10. #30

    Join Date
    Dec 2001
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    8,470

    Re: 1800mm APO Nikkor

    Quote Originally Posted by Pawlowski6132 View Post
    Why would anyone use this?
    Why not? Large negatives require a lens with large coverage.

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