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Canon 24-70mm f2.8L and extension tubes


john_dickinson

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Hi, I have the canon 24-70 2.8 L and I am thinking of purchasing a

25mm extension tube for macro shots. The lens instruction booklet

states a 1.25x magnification will be achieved at 24mm with the EF25.

However I have noticed some sellers of the lens state it is 'Only

compatible at Tele 70mm'. I can find nothing to confirm this

restriction on the canon / eos websites. Please can anyone enlighten

me. Thank you.

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You might be better off buying a full set of Kenko extension tubes. They are a better value than the single Canon tube, and they are completely compatible with EOS cameras and lenses. I use extension tubes with my 28-70/2.8, and I find that trying to use the wide end (28mm) is difficult. The focusing distance is too small---I have to take off the hood, and the object has to be VERY close to the lens (distances measured in millimeters). Since I use a flash unit for most of my macro shots, this is too impractical. I would imagine that using a tripod and the wide end would make things slightly easier. Using the long end is much easier, and with a full set of tubes, I can get to 1:1 +/-.

 

I don't know anything first hand about the Canon tube. If it is anything like the Kenko (just a hollow tubw w/lens contacts), I'd guess that you don't actually *lose* compatibility at less than 70mm, but that usage just becomes more and more difficult.

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Yes go with the Kenko tubes. This is the only item that I will recommend over Canon. Since there is no glass they will not effect the quality of the lens. The Canon 25mm tube is $85 to $95 and the full set of Kenkos is $119 at adorama. that would include a 12mm, a 24mm and a 36mm. All togetehr thse would act lie a bellows and with a 50mm and a 100mm and longer for great Macro. I am getting a set to use with my 70-200. At 200mm and a couple of tubes I should have some awesome macro!
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The Canon EF25 tube (which I believe actually provides about 27mm extension) has three extra contacts at the front end; these are not present on the EF12 tube. Does anyone actually KNOW what these extra contacts do? My GUESS is that they provide information used by the 50/2.5 macro lens, but not by the L-series lenses. I have the 50/2.5 lens and the Life Size Converter, and the lens does pick up information from the converter through the extra contacts on each.
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Hi, I have both and the 12mm, the reason for the

recommendation to only use at the 70mm end is obvious when

you try to use the 25mm tube at the 24mm setting, lens to

subject distance. I have not measured the front surface to object

distance but it is in the region of 3 inches! This makes it

impracticle for most subjects.

On a more important note, despite the lenses hefty structure

and build quality, the hood mount and sealing ring from the front

of my lens fell off.

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Thank you for the helpful replies. On balance it makes me consider the Kenko Extension Tube set 12, 20 & 36mm (£90 in UK money) rather than canon. I just worry incase I will lose any canon compatability. I also have an opportunity to purchase a canon 500D closeup lens and wonder how effective are these - I have the 70-200L and 100-400L which are also 77mm. I have no prior experience of close up work but am interested to experiment.
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I bought both Canon 12 and 25 ETs. 12 mm extension reduces light by 1/2 a stop, 25 mm by 1 stop. I was wondering that 20 and 36 mm Kenko extensions would be (in case that aperture/shutter time are not stepless) somehow incompatible. Also I was afraid about autofocus on my 400/5.6 in case of 36 mm extension. There are 12 and 25 mm Kenko ETs too but they are priced very close to the ones from Canon. Why?

 

Hope it helps,

 

Fero

www.wnp.sk

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