I have been looking at some macro extension tubes, you know, the empty tubes you
put between your body and your macro lens, to get an even bigger magnification.
Has anyone used these, what are the advantages and disadvantages.
I saw there are 2 kinds, cheap, were you have no lock on the tubes, they just slide in to each other
or the more expensive kind, where you have a metal alpha coupling.
Your thoughts please and maybe some examples