Didn't realize there were different versions of the extension tubes. If you mean the tele convertors, both the 1.4 and the 2X have had their optics redesigned. The 1.4 apparently isn't very different but the 2x is supposed to be sharper. One other difference is that the version II tubes can be mated together without needing an extension tube in the middle to compensate for the extending front element.
If you are meaning the extension tubes (the hollow ones for closer focussing) the Kenko ones made for Canon do an excellent job for considerably less money.
Discussion
3 repliesThanks, Don
If you are meaning the extension tubes (the hollow ones for closer focussing) the Kenko ones made for Canon do an excellent job for considerably less money.
My apologies if I misunderstood your question.
Interestingly, that means you could put an EF-S lens on a full frame camera using a tube...not that you'd want to, but you could...
Cheers,
I believe you are correct - version II can support EF-S lenses.
Don