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Thread: Why don't they make extension tubes adjustable?

  1. #1

    Default Why don't they make extension tubes adjustable?

    For example, like a sliding tube which user can adjust the tube length. bellows look
    cubersome and fragile, plus it's expensive.


  2. #2

    Default Re: why don't they make extension tubes adjustable?

    To make a sliding metal/plastic tube that is also light tight with mounts on either end would probably be just as if not more expensive then manufacturing belows.
    sk.images, ex - cyber_m0nkey

  3. #3
    Moderator catchlights's Avatar
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    Default Re: why don't they make extension tubes adjustable?

    the lens is already adjustable, why should make the tube adjustable, the tube still have to do the coupling of aperture, it will make the tube "cumbersome and fragile, plus it's expensive" also.
    Shoot to Live, Live to Shoot
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  4. #4
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    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by dRebelXT
    For example, like a sliding tube which user can adjust the tube length. bellows look
    cubersome and fragile, plus it's expensive.

    Later you will ask why the extension tubes creep?

    Regards,
    Arto.

  5. #5

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by dRebelXT
    For example, like a sliding tube which user can adjust the tube length. bellows look
    cubersome and fragile, plus it's expensive.

    I think I came across one which is adjustable a number of years back.

    Here's one for OM mount.
    http://www.alanwood.net/photography/...auto-tube.html

    And here's one for Pentax.
    http://www.bhphotovideo.com/bnh/cont...goryNavigation

  6. #6

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by cyber_m0nkey
    To make a sliding metal/plastic tube that is also light tight with mounts on either end would probably be just as if not more expensive then manufacturing belows.
    Just wrap a black cloth around the opening while holding the lens with your hand. Can tilt and shift somemore.

  7. #7
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    Default Re: why don't they make extension tubes adjustable?

    They did, and its called lensbaby..

  8. #8

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by lsisaxon
    Just wrap a black cloth around the opening while holding the lens with your hand. Can tilt and shift somemore.
    This would be fun to try, bu the depth of field wide-open would be impossible to use.
    sk.images, ex - cyber_m0nkey

  9. #9

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by cyber_m0nkey
    This would be fun to try, bu the depth of field wide-open would be impossible to use.
    But then you can tilt to get sharpness across your field.
    http://www.trenholm.org/hmmerk/SHSPAT.pdf

    Otherwise, borrow a Nikon mount lens with an aperture ring to try. Then again, with the aperture stopped down, the image would be so dim that it's near impossible to hold still and get a decent exposure too.
    Last edited by lsisaxon; 4th July 2006 at 02:37 PM.

  10. #10

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by lsisaxon
    Borrow a Nikon mount lens with an aperture ring to try.
    Good idea, but that would be sacrilege, like Luke using Darth Vaders light saber. I will use my 645 Mamiya lenses instead , these would be better anyway as they throw a larger image circle.
    sk.images, ex - cyber_m0nkey

  11. #11

    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by cyber_m0nkey
    Good idea, but that would be sacrilege, like Luke using Darth Vaders light saber. I will use my 645 Mamiya lenses instead , these would be better anyway as they throw a larger image circle.
    Sorry, I'm a Nikon person. Using Mamiya would be a better solution for you.

  12. #12
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    Default Re: why don't they make extension tubes adjustable?

    Olympus make the 1st adjustable extension tube many many yrs ago, provides full flexibility to extent between 65-116mm, there is a lock at any preferred extensions.

    I bought this for my OM system recently... with the 90mm macro, I can achieve ~2x magnification at f2.

    http://www.star.ucl.ac.uk/~rwesson/e...ube_65-116.htm

    Still available in the ebay, u can buy it to use with Olympus E DSLR system too, but will need adaptor.
    Last edited by boochap; 6th July 2006 at 01:35 PM.

  13. #13
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    Default Re: why don't they make extension tubes adjustable?

    Quote Originally Posted by Artosoft
    Later you will ask why the extension tubes creep?

    Regards,
    Arto.
    Also ask why the extension tubes cannot autofocus?

  14. #14

    Default Re: why don't they make extension tubes adjustable?

    the Triplus extention tubes does AF.
    if extention is required, maybe the user may have to look into bellows.

  15. #15
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    Default Re: Why don't they make extension tubes adjustable?

    I do own an extendable extension tube for Canon FD.
    Beautifully made.

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