Uncle_BobAdaptor rings aren't just for mirrorless cameras. I have an adaptor that allows me to use the lenses from my old Minolta on my Canon T5. Aside from having to shoot in manual mode, the other disadvantage is that those big old steel-and-glass telephoto and lenses weigh A LOT more than modern composite lenses. As others have said, a good tripod is essential, but especially if you use long and/or heavy lenses so that your camera doesn't inadvertently jerk when you take pictures. Not sure if anyone has mentioned this, but if you're interested in heading out to take pictures in the great outdoors, such as passing trains , you can turn many DSLR's and some point-and-shoot cameras into video cameras. Happy camera shopping!