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  1. #21
    Mike Kovacs's Avatar
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    I use tubes (bellows) and close-up lenses. The quality argument just doesn't hold water under the conditions I usually shoot in - outdoors without flash.

    The Nikon two element close-up lenses work very well, especially with my old 80-200/4.5 multicoated zoom-Nikkor. Magnification with diopters increases with focal length, so I use the zoom is a sort of macro zoom. Stopped down to macro typical ranges, critical sharpness is there.

    Secondly, there is no light loss from extension using the tubes. There are many times where I would simply not be able to make a shot in the field due to subject motion, were I to lose another stop or two of light from extension tubes and/or bellows.
    If it says Zeiss or Rollei, the answer is YES!
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  2. #22

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    Quote Originally Posted by Mike Kovacs View Post
    I use tubes (bellows) and close-up lenses. <snip>

    Secondly, there is no light loss from extension using the tubes. There are many times where I would simply not be able to make a shot in the field due to subject motion, were I to lose another stop or two of light from extension tubes and/or bellows.
    Huh? At what magnification is there no loss from gaining magnification by adding extension? Did you mean to say there's no loss from using diopters?

  3. #23
    Anupam Basu's Avatar
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    Quote Originally Posted by Dan Fromm View Post
    Huh? At what magnification is there no loss from gaining magnification by adding extension? Did you mean to say there's no loss from using diopters?
    Dan, are you saying there is no light loss with diopters? I thought there is light loss with magnification, period.

    -Anupam

  4. #24

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    No light loss w/diopters is correct. That's the biggest advantage to them.
    Light weight & compact size also help.
    There is light loss w/tubes or bellows though.
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  5. #25
    Anupam Basu's Avatar
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    Quote Originally Posted by John Koehrer View Post
    No light loss w/diopters is correct. That's the biggest advantage to them.
    Light weight & compact size also help.
    There is light loss w/tubes or bellows though.
    I don't think so. Light is not quite 'lost.' It is spread out to cover a larger area and so correspondingly loses intensity. Just like an enlarger making an 8x10 print will need 4 times more exposure (2 stops) than when making a 4x5 print (1/4 the area of an 8x10). This spreading out happens no matter what method you use to achive the magnification and so there is an equal loss of light intensity.

    -Anupam

  6. #26
    Lee L's Avatar
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    Mr. Koehrer is correct. Lens extension tubes increase the lens to film distance, and so light intensity per square unit of area decreases. However, diopter lenses shorten the lens to subject distance, and do not change lens extension from the film plane, so light intensity per square unit area on the film isn't changed.

    If you want to stick with the enlarger analogy, projecting the same size negative with a 50mm or a 100mm enlarging lens, both to the same size final print, will still give you the same light intensity on the paper with the same f-stop.

    Lee

  7. #27
    Anupam Basu's Avatar
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    Quote Originally Posted by Lee L View Post
    Mr. Koehrer is correct. Lens extension tubes increase the lens to film distance, and so light intensity per square unit of area decreases. However, diopter lenses shorten the lens to subject distance, and do not change lens extension from the film plane, so light intensity per square unit area on the film isn't changed.

    If you want to stick with the enlarger analogy, projecting the same size negative with a 50mm or a 100mm enlarging lens, both to the same size final print, will still give you the same light intensity on the paper with the same f-stop.

    Lee
    How is magnification achieved without spreading out the light? The fact that 50mm and 100mm enlarger lenses at the same print size will give the same times just confirms my point that it is the enlargement size of the print and not the distance that matters.

    I had the same idea from John Shaw that diopters don't lose light. But Bjorn Rorslett corrected me on another forum and I have since done many tests to confirm his claim. See this thread for that exchange.

    -A

  8. #28
    naturephoto1's Avatar
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    Quote Originally Posted by Anupam Basu View Post
    How is magnification achieved without spreading out the light? The fact that 50mm and 100mm enlarger lenses at the same print size will give the same times just confirms my point that it is the enlargement size of the print and not the distance that matters.

    I had the same idea from John Shaw that diopters don't lose light. But Bjorn Rorslett corrected me on another forum and I have since done many tests to confirm his claim. See this thread for that exchange.

    -A
    Hi Anupam,

    The diopters (the Nikon, Canon, and Leica Elpro are 2 or more? elements and do produce very very good to excellent results) have a negligible amount of light loss when mounted on the camera lens. There is substantially less light loss than working with extension tubes, extenders (basically an extension tube with lens elements), or a bellows. Regardless of the conversations on other sites or threads, if you question the small to no light loss of using such lenses just meter with your 35mm or medium format camera through the lens alone and/or through the lens with these diopter lenses attached. That will confirm how little light is actually lost. These lenses allow for much greater working distances than the extension tubes or bellows. I assure you you will see little (perhaps 1/6 stop or so) or no change to your meter reading.

    Rich
    Last edited by naturephoto1; 10-20-2006 at 09:09 AM. Click to view previous post history.
    Richard A. Nelridge
    http://www.nelridge.com

  9. #29
    Ole
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    The diopter changes the effective focal length of the lens, so that the same extension gives a higher magnification. The "light loss" is the same at the same magnification, but since the effective focal length is shorter, the effective aperture is larger [/i]at the same setting[/i].
    -- Ole Tjugen, Luddite Elitist
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  10. #30
    Anupam Basu's Avatar
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    Quote Originally Posted by naturephoto1 View Post
    Regardless of the conversations on other sites or threads, if you question the small to no light loss of using such lenses just meter with your 35mm or medium format camera through the lens alone and/or through the lens with these diopter lenses attached. That will confirm how little light is actually lost. These lenses allow for much greater working distances than the extension tubes or bellows. I assure you you will see little (perhaps 1/6 stop or so) or no change to your meter reading.
    TTL metering is exactly what I have been using to make my claims. And in my experience extension tubes give much more working distance than diopters with the same magnification.

    Ole, that is very well explained. I agree.

    -Anupam

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