Extension Tubes and Close-up photography

Discussion in '35mm Cameras' started by Ken, Nov 3, 2003.

  1. Ken

    Ken Guest

    What is your opinion of using extension tubes to inexpensively get into
    close-up and "macro" photography? How do they compare to close-up filters?

    I have a Canon EOS Elan II and have read some good things about the Kenko
    Extension Tube Set and wondered if this would be a good start for me. I've
    also read some books about photography and one professional claimed he used
    extension tubes for his photographs in his book and the pictures were very
    good.
     
    Ken, Nov 3, 2003
    #1
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  2. Ken

    Annika1980 Guest

    From: "Ken"
    Extension tubes are a great (inexpensive) alternative to expensive macro
    lenses.
    I have the Kenko set of 3, and I use them a lot when I do insect pics like the
    praying mantis I featured in this week's Shoot-In.

    http://www.pbase.com/image/22920790
    http://www.pbase.com/image/22920789

    By stacking the tubes, you can get really close, and the best part is that they
    don't introduce any distortions since they are simply spacers with no
    additional glass.

    The only drawback is the limited Depth of Field that they create, so you must
    be careful when focusing.
    Can you say "Focus Bracketing?"
     
    Annika1980, Nov 3, 2003
    #2
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  3. Ken

    Vin Guest

    Hi,

    I've used close-up filters, tubes and macro lenses. Firstly, Ive
    never used high quality closeup filters such as the Nikon
    and Canon ones. (They probably are about the same price as tubes.)

    Close-up filters that I have used give very low contrast, tend
    to flare and give chromatic aberations even at small
    apertures. The only advantages are that they are small, easier
    to change and you dont have any loss of light.

    Extension tubes, are a real hassle to use in the field as they
    are fairly clumbersome to change around, especially if you need
    to change the magnification a lot. That said, when used with a
    good 50mm lens, the quality is very nice. You probably dont want
    to use tubes on much longer lens, as to get to 1:1 on a 200,
    you need to have 200 extension (well, at infinity anyway), but
    you can see that you will need a lot of extension. If you
    want a tele-macro, your probably better off getting the diopters,
    if you are going on a budget.

    The only macro I've got is the Sigma Apo 180HSM and it is much
    more convienient to use than the other two as you dont have
    to fiddle around with other accessories, if you need to change
    the magnification. Very sharp, but its not much better than using
    a 50mm+50mm of extension.

    Vin.
     
    Vin, Nov 3, 2003
    #3
  4. Ken

    Tony Spadaro Guest

    Extension tubes are not convienient but do yield a much better final image
    than close-up rings. You will, in fact, get as good a picture as your lens
    is capable of giving since there are no glass elements in the extension
    tubes - they are simply light tight tubes with the proper connections. I
    know a couple people with Kenkos and they are quite happy with them.
     
    Tony Spadaro, Nov 3, 2003
    #4
  5. Yes, the Kenko extension tubes are fine - I've used them on my EOS 33 (Elan
    7 to some). I don't necessarily agree with the "inconvenience" factor -
    yes, you do need to shuffle the tubes to get the right combination, but
    macro work is generally fairly slow and methodical anyway.
     
    Steve Marshall, Nov 3, 2003
    #5
  6. Ken

    Ken Guest

    Thanks for all the helpful info.
     
    Ken, Nov 3, 2003
    #6
  7. Whilst it is true that extension tubes can produce good results with
    some lenses, I really wish people would stop making the almost universal
    assumption that "no glass in tube equals no damage to image quality"; it
    simply does not work like that.

    All lens designs are a compromise between controlling the various
    aberrations (in a balanced manner) and keeping cost to a reasonable
    figure. Most times, this involves keeping spherical aberration under
    control over a reasonable range of object/image distances and letting it
    go hang outside this range. The bigger the focus range used, the more
    effort has to go into using floating or aspherical elements, and the
    larger and more expensive the lens gets.

    Increasing the image distance beyond the design figure may have a slight
    impact on quality, or it may fall apart very badly, depending on the
    lens design. Broadly, fixed focal length lenses of the standard to
    moderately long tend to be the least affected; wides and zooms tend to
    be the worst. Also bear in mind that some wides (fixed or zoom) will
    produce vignetting.

    Thus you will have to try the particular lens you have to see if it will
    work well with an extension tube.

    Of course, a dedicated macro lens which is designed to work specifically
    with an extension tube may be very good - in that case, it is really a
    question of the "design range" I spoke of above including the use of
    such a tube.

    Also, bear in mind that with tubes on some bodies the metering may not
    work without adjustment, and AF will be severely compromised or useless.

    If you are going to produce nothing more taxing than 5x7 prints or
    pictures for the web, then you may well find a good supplementary lens
    gives perfectly satisfactory quality; they will allow AF and unaltered
    metering with most bodies, and are much simpler to use in the field.

    Whichever method you use, for real macro shots you will find AF is
    mostly useless and you will be using the eyeball method. It is almost
    always necessary to focus by leaving the lens alone and moving the whole
    camera/lens assembly back and forth.
     
    David Littlewood, Nov 3, 2003
    #7
  8. Ken

    parv Guest

    Does such a lens exist in 35mm format? How about in other formats?


    - parv
     
    parv, Nov 3, 2003
    #8
  9. Ken

    parv Guest

    Does such a lens exist in 35mm format? How about in other formats?


    - parv
     
    parv, Nov 4, 2003
    #9
  10. Ken

    Bill Hilton Guest

    Of course, a dedicated macro lens which is designed to work
    Several of the 50 mm macro lenses don't go to 1:1 without an extension tube (I
    think the Canon is an example), which is usually included as part of the deal.


    I once owned a very sweet Minolta 100 mm f/3.5 macro (manual focus era) that
    also went to just 1:2 by itself and to 1:1 with the included extension tube.

    Bill
     
    Bill Hilton, Nov 4, 2003
    #10
  11. Ken

    parv Guest

    Sorry for the double post; i thought the first did not go.



    - parv
     
    parv, Nov 4, 2003
    #11
  12. Ken

    Bandicoot Guest

    As well as the types of lens Bill mentions, there are lenses specifically
    designed for bellows use, which have no focusing helix of their own. The
    Pentax 100mm bellows lens can be used on bellows (d'uh) and also with a
    thing called a helicoid extension tube, which is like a stand alone focusing
    mount, in which case the lens will focus to infinity as well as pretty
    close.

    Such bellows lenses also exist in medium format - I know of at least one
    Zeiss and several Schneiders.



    Peter
     
    Bandicoot, Nov 7, 2003
    #12
  13. Ken

    parv Guest

    Thanks much for the education, Peter.


    - parv
     
    parv, Nov 7, 2003
    #13
  14. The Zeiss Luminars of the 1960s and 70s were legendary. There were
    (IIRC) 5 in the range, of which the shortest 4 (16, 25, 40 and 63mm)
    have RMS mounts and the longest has a larger screw diameter and an
    adapter to fit a Zeiss dovetail for microscope mounting. There are also
    3 Epi-Luminars (16, 20 and 40mm) designed for use with incident
    illumination using an internal 45 degree glass reflector.

    Canon also made 2 bellows macro lenses, 20mm and 35mm, again with RMS
    threads, with an adapter to fit them on the bellows (all FD fit, Canon
    have not AFAIK sold an EF-fit bellows).
     
    David Littlewood, Nov 9, 2003
    #14
  15. Ken

    parv Guest

    What does RMS stand for? (The ones i know of are "root mean square"
    and " Richard Matthew Stallman".)


    - parv
     
    parv, Nov 10, 2003
    #15
  16. Royal Microscopical Society. This London-based society first
    standardised the threads which have been used since on virtually every
    microscope - except toys - and the other critical dimensions as well.
     
    David Littlewood, Nov 10, 2003
    #16
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