I've been experimenting with using vintage film lenses on my full frame DSLR cameras. This is one of my most recent finds, and one I'm just finally getting the hang of. It's Canon FD 70-200 f/4 and when using it (even at 70mm) has the most amazing bokeh! It even has macro capabilities.
The main downside is that the lens is manual focusing, so catching fast moving bug and kids can be a challenge, but I'm improving every day and learning the tricks of continuously manuall