Tonight I did a bunch of tests with an old lens that my parents probably bought in the late 70s, if not early 80s. It's a Canon 50mm 1.8 prime, just like the one I have for my DSLR, but cooler. It's actually made out of metal.
Anyway, the mount is different than the modern cameras, and I cannot fit it onto my Canon 20D. But if I hold it up to the camera JUST RIGHT, I can get some shots in focus. I might be able to rig something up someday that will let me attach it somehow, but not sure. In the interest of time, I'll post these with no captions. They're just all tests.
EDIT, Nevermind for some reason I had in my head that it was a Nikon, even though it blatantly says Canon. Thats an old trick to get old F-Mount lenses to work on new Nikon bodies.