Cheap Extension tubes - Are they worth it?

[PoW]

http://cgi.ebay.co.uk/MACRO-TUBES-Full-Set-For-Canon-Eos-350d-400d-40d-1ds-UK_W0QQitemZ250218985690QQihZ015QQcategoryZ30070QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Ajophotog]

Don't bother you will only buy an auto set afterwards, save your cash and put it to the auto set ;)

[Canon Bob]

If you know that you want tubes then they're not worth it. If you're just finding out what tubes will give you with your lens line up, then they'll be okay.

One thing to be aware of with these.....the threads can shed a little aluminium when being screwed together so mount the tubes to the camera body and lens after assembling desired tube configuration and then have a good shake and blow.

Bob

[PoW]

Thanks guys. With it basically being a spacer ring (sort of car terminology) i thought as long as they marry up ok on the joints all will be good. AJ, you mention the auto set. I take it the ones you mentioned which I cant remember right now had the auto focus feature. I was thinking that because the AF on my macro lens did not work then this was a VERY cheap way to get the extra Magnification.

[Canon Bob]

It's the aperture, not the focus, that you'll be restricted by.

Bob