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  1. #11

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    No mention of Zoomar? They produced both a 180/1.3 and a 240/1.2 (the 240 even covered medium format). If you include effective aperture, the Zeiss N-mirotar is about f/.03, but it is just a f4 or so mirror lens with a couple of image intensification tubes. Nikon also made a 58/1.0; one popped up on ebay a couple years ago, I'll try to post pictures if I can find them. If anyone's curious, the macrolenses.de site has some pictures of a couple of f/0.75 lenses. As Maris mentioned, oil immersion microscope objectives exist that are larger than f0.5.

  2. #12
    ic-racer's Avatar
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    Quote Originally Posted by Dirb9 View Post
    If anyone's curious, the macrolenses.de site has some pictures of a couple of f/0.75 lenses. As Maris mentioned, oil immersion microscope objectives exist that are larger than f0.5.
    Nice! Anyone know what these fast lenses "X-Ray" lenses were used for? Pictures from dim fluroscopy screens maybe?

  3. #13

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    You would just expose the film longer in screen cameras. Not use very expensive fast lenses.

    Why do you call this an "X-Ray" lens?
    (For those who don't know, it's not the obvious, since you can't focus X-rays with glass lenses. )

    P.S.
    Thanks to Google:

    The Picker Corporation presented ELCAN Optical Technologies with their problem: the proposed system was optically inefficient and could not produce bright enough images. The challenge lay in optimizing the coupling of the radiographic image intensifier's output to the recording media (film) in order to maximize the brightness and resolution of the image. The system required an extremely high performance lens that could capture and focus the available light.

    Typical of ELCAN Optical Technologies, the solution was derived from working backward from the limiting factor - the sensitivity of the film. High-speed imaging necessitated the maximum amount of light reaching the film and high definition of the individual X-ray images onto the film.

    The ELCAN - Picker lens solution was a projection lens with maximum transmission capabilities, an "F:1" lens. The extremely bright F:1 lens optimized the aperture (without compromise to image quality) , therefore maximizing the amount of light captured. The result was a clear, sharp x-ray image revolutionizing the medical imaging market.

    SOURCE: ELCAN Optical Technologies

    They would need "high speed imaging" because they were taking moving pictures, not stills. So my "expose the film longer" was not an option.

  4. #14
    ic-racer's Avatar
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    Quote Originally Posted by Q.G. View Post
    You would just expose the film longer in screen cameras. Not use very expensive fast lenses.
    Of course the patient isn't going to hold still either!

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