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Author Topic: Canon extension tubes  (Read 2455 times)

pamelavlcek

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Canon extension tubes
« on: February 18, 2018, 02:13:12 pm »

I bought the Canon Extension Tube EF25 II to use with my Canon 5DS R to get a closer minim focus distance but I can get it to focus at all...tried auto/manual focus with/without IS on all my lens 100mm f2.8 L macro, 16-35mm f4 L, 24-70mm f2.8, 70-200mm f4 L...you get the picture. So I'm wondering is the 5DS R not compatible with the tubes or is there some thing I'm missing here? thanks
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pamelavlcek

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Re: Canon extension tubes
« Reply #1 on: February 18, 2018, 03:39:56 pm »

Whoops I mean "can't" get it to focus...really at my wits end about why...nothing I google mentions anything about not focusing and since it's just a tube I can't see how it could be at fault...help
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BobShaw

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Re: Canon extension tubes
« Reply #2 on: February 18, 2018, 04:48:43 pm »

Have you read the instructions?
Auto focus is not recommended and you will get poor results with zooms usually.
Zooms need to be at the maximum zoom to have any effect and then the the minimum subject distance is too small.

If all else fails set it to minimum focus distance and move the subject until you see the range.
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pamelavlcek

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Re: Canon extension tubes
« Reply #3 on: February 18, 2018, 05:39:08 pm »

instructions...lol well it was used so no instructions...the first lens I tried it on was the 100mm and I did try it on auto and manual focus...I used the full focus ring from closest to infinity it never came into focus...would the f stop effect this?...I am about ready to return it if it is this difficult to focus...thanks for your suggestions I will retry again tomorrow...
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pamelavlcek

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Re: Canon extension tubes
« Reply #4 on: February 18, 2018, 05:45:14 pm »

I was able to google the manual for the tube so thanks for suggesting it...
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Slobodan Blagojevic

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Re: Canon extension tubes
« Reply #5 on: February 18, 2018, 06:05:13 pm »

It is most likely a user error. You need to know what you are doing. It is absolutely impossible not to achieve a manual focus with an extension tube. There is no magic there, no glass inside. Just put it on, use the manual focusing and focus using the back screen on your camera (a.k.a. live view). The manual (or internet resources) will tell you what the optimum focusing distance would be for each lens (and focal length - usually above 50mm). Put the subject within that range and try. The depth of field for macro photography is razor thin. So, if the subject is not in that range, you can't focus, of course. Once you are able to determine the optimal range, you can try AF, it should work too.

pamelavlcek

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Re: Canon extension tubes
« Reply #6 on: February 18, 2018, 06:08:12 pm »

So I should use live view?...I was using the eye piece...thanks will try tomorrow...I figured it was something I was not doing...so one question...you can only focus on the minim distance but can't use the lens in a normal manner with it on?...
« Last Edit: February 18, 2018, 06:11:48 pm by pamelavlcek »
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Slobodan Blagojevic

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Re: Canon extension tubes
« Reply #7 on: February 18, 2018, 06:10:36 pm »

So I should use live view?...I was using the eye piece...thanks will try tomorrow...I figured it was something I was not doing...

And a tripod. Because of the razor thin DOF, your hand shake and body movements will make it difficult to focus.

francois

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Re: Canon extension tubes
« Reply #8 on: February 21, 2018, 04:45:41 am »

And a tripod. Because of the razor thin DOF, your hand shake and body movements will make it difficult to focus.
Yes, the issue is probably the "razor thin DOF" as written above by Slobodan. Depending on the lens, even on a tripod, focus can be tricky.
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Francois

NancyP

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Re: Canon extension tubes
« Reply #9 on: February 22, 2018, 08:37:40 pm »

Manual focus is much less aggravating than auto-focus when doing close-up and macro photography. Canon Live View is great, and you have the option to magnify to check focus.
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