Extension Tubes - Full Disclosure

Ok, I've been talking about tubes ever since joining PR and have posted some real-world examples in this forum.

So here are some test examples which I hope you find helpful. I thought pencils would be a good universally recognizable (and stationary :p ) subject.

Since there are so many variables, the following will remain unchanged throughout:

Lens: 70-200 f/2.8L IS
Aperture: f/8
ISO: 200
Focus: manual (rack focusing) at minimum lens setting
Metering: AV
Mirror Lockup: enabled
Shutter Release: remote
File Capture: RAW
Post Processing: None except resize and convert to JPEG (no cropping)

The setup:

Images with NO extension tubes.

Left to Right:
70mm @ 112cm working distance (subject to front of lens)
135mm @ 112cm working distance
200mm @ 112cm working distance

Images with 12mm extension.

Left to Right:
70mm @ 29cm working distance (subject to front of lens)
135mm @ 62cm working distance
200mm @ 81cm working distance

Images with 20mm extension.

Left to Right:
70mm @ 18cm working distance (subject to front of lens)
135mm @ 48cm working distance
200mm @ 70cm working distance

Images with 36mm extension.

Left to Right:
70mm @ 8cm working distance (subject to front of lens)
135mm @ 33cm working distance
200mm @ 56cm working distance

Images with 48mm extension.

Left to Right:
70mm @ 5cm working distance (subject to front of lens)
135mm @ 27cm working distance
200mm @ 48cm working distance

Images with 56mm extension.

Left to Right:
70mm @ 4cm working distance (subject to front of lens)
135mm @ 23cm working distance
200mm @ 45cm working distance

Images with 68mm extension.

Left to Right:
70mm @ 2cm working distance (subject to front of lens)
135mm @ 20cm working distance
200mm @ 40cm working distance

Remember, changing the focus on the lens at any time will also affect the working distance and magnification. The bottom image is still with the 68mm extension at 200mm, except now the focus on the lens is set to infinity. Working distance has now increased from 40cm to 62cm. The magnification is now about the same as it was when only the 36mm tube was used with the lens set at the mininum setting.

200mm with 48mm extension.

Slightly off perpendicular (sharpened pencil is out of DOF), angled, and post processed with PS.

This is the final example. Hope this helps demonstrate the flexibily that these things offer and why I love 'em so much :thumbsup:

Thanks for the demenstration Loupey! That must have taken some time to do all that and it's much appreciated!

What focusing rail are you using?

Thanks for clearing things up Loupey , now all i want is to C what they look like :) How about electrical contacts or do you have to go all manual with these ?

Very nice demonstration. Thanks for the time and trouble.

Quote:

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Originally Posted by mjs1973

Thanks for the demenstration Loupey! That must have taken some time to do all that and it's much appreciated!

What focusing rail are you using?

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No problem, Michael! At first, I was going to show the corresponding magnifications/working distances with the focus at infinity for all extensions, but that was just too many combinations :p

I thought you were going to ask me to do the same set of examples with my 2x TC. One set with the TC in front of the tubes and another set with the TC behind the tubes!

I have a Contax focusing rail that I bought at a second-hand dealer in Canada a few years back. It was actually part of a bellows kit. I negotiated a lower price just for the rail as I didn't need/want the bellows. I don't know how the dealer was going to sell just the bellows to someone else :p I don't use it in the field but it works great in a controlled setting.

Quote:

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Originally Posted by Knight

Thanks for clearing things up Loupey , now all i want is to C what they look like :) How about electrical contacts or do you have to go all manual with these ?

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The electrical contacts allow full communication (even through all 3 tubes) between the body and the main lens. Even internal stabilization capability is preserved. Still, I shoot manual focus anyway.

Quote:

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Originally Posted by Old Timer

Very nice demonstration. Thanks for the time and trouble.

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Your welcome! Just here to give (hopefully) wanted advice, demonstrations, and examples. I know you already shoot fantastic macro work, but I wanted to show that there are different ways to skin a cat. I'm all for using existing equipment to its full capabilities and knowing just how far they can be pushed :thumbsup:

Thanks for all the info Loupey :)

Yes thanks greatly for this Loupey, your time and effort on this is appreciated, its really shown these tubes full potential, and its good to actually see one. Iv looked around here for these but only come across very limited sizes in Canon, any suggestions on manufacturers/suppliers. regards.

www.bevbarkerphotos.com
www.k9imageworld.com

Quote:

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Originally Posted by Bevb

Yes thanks greatly for this Loupey, your time and effort on this is appreciated, its really shown these tubes full potential, and its good to actually see one. Iv looked around here for these but only come across very limited sizes in Canon, any suggestions on manufacturers/suppliers. regards.

www.bevbarkerphotos.com
www.k9imageworld.com

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Yeah, not the subject you were expecting, eh :D ?! Canon only makes 12mm and 25m tubes and each costs about $180US/each. Must have gold in them.

I paid $180 for the set of 3. It is labled for the camera dealer network in my region but I think it is manufactured by Tokina. The Kenko tubes seem highly recognizable in these forums.

Yes thanks Loupey have found info on this now. regards.

These are fantastic tubes, and you've showed a wonderful demonstration of their ability.

Should be a sticky in the Camera Equipment section. or a review on the home page. Good Job!

Quote:

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Originally Posted by SpeedingSphere

These are fantastic tubes, and you've showed a wonderful demonstration of their ability.

Should be a sticky in the Camera Equipment section. or a review on the home page. Good Job!

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Thanks, SS. Knowing that you recently purchased your Kenko tubes, I was hoping that you would chime in with your thoughts on them :p

I recall only seeing a few shots that you took with the tubes on your beloved 400mm. Do you have any more that you can post in this forum? Love to see what you've got.

I havnt used them much yet, but look out, youre going to get plagued once I come back from bermuda. studying for school finals this next week, so you wont hear much from me, and then the week after, bermuda, so figure a wait of about 2 weeks.

I cant wait for this trip. The trip is why i bought a monopod, L glass, extention tubes, camcorder, and some other stuff. I'm sooooo excited!

:-)

I have now ordered my set of Kenko tubes and cant wait to have a play with them, and they were so reasonably priced to! (£47) thanks Loupey for bringing these to my attention and for a fantastic thread on them.

Speeding Sphere, Woe sounds like a trip of a lifetime! have a brill time and look foward to some pictures on your return.

www.bevbarkerphotos.com
www.k9imageworld.com

Now this is a STICKY without a doubt!

You've done great !

Loupey-
This is an excellent, excellent post! Thanks a lot for making it. I'm sure it's very useful to lots of people. And it reminds me that we need a place for this kind of thing so that it can be easily found. I'm not sure how to go about doing that yet, although there has been talk of a photo tips forum.

In the meantime, I checked the reviews and although the Kenko tubes are listed, I could find no review from you! So please post one for us. Here's a link to that review page: http://www.photographyreview.com/cat...3_3132crx.aspx

Thanks - this is awesome. I love it when people take the time to make something really useful like this post. :thumbsup: