They go on my wish list.

Those are the ones I recommend. They are fairly expensive, but after years of use I've never had a coupling problem with them. I ditched a set of cheap tubes (don't remember the brand) because after a few months they started developing electrical coupling problems, even after cleaning the contacts. After checking around I found that's a pretty common complaint with many of them. That's not to say none of the cheaper ones are good, but it's something to look for when you are checking out the reviews.

You wouldn't want to use tubes for focusing at a distance because their only real purpose is to decrease the minimum focusing distance of whatever lens you are using them on (which increases magnification).

Last edited Mon Feb 17, 2014, 10:19 PM - Edit history (1)

I can't post a link to my head shot of a house fly 'cause I'm relegated to my tablet.

Buy any cheap bellows, a t2 adapter for your camera and a lieca thread adapter and 2 part epoxy is your friend. 10 x life size magnification!

Edit to add
Bellows plus all adapters runs about $40 not counting enlarger lenses (about $10 each for highest quality) and it depends on your DIY skills.

I have a set of manual tubes and have fooled around with them in the past, but auto would be pretty cool and these you mention are not too expensive.