This is kind of fun... while I was researching microscopes, I found this web site. He took photos of coins through each eye tube and put them side/side on the web. If you get close to your monitor and do the "cross-eyed" trick, you can create a cool 3d image of the coin with no lenses or tools of any kind.
Look at the paired coin images about half-way down:
http://dougsmith.ancients.info/micro.html
It's a bit like those crazy pictures where if you stare just right, a rocking 3d image pops out.