Originally posted by Gewi6410 Just done a bit of research online. Its an adaptor for an M42 lens. I think my father in law had quite a few m42 lenses. Are they worth playing about with?
Yes, some of them. Do a bit of reading here, there's quite a fan club. It's fully manual though, so it's more work.
On the plus side, nothing will teach you about exposure like a fully manual lens! Pentax gives you the tools for manual work but modern viewfinders aren't as good for manual focus - it will take time.
M42 will open you to a whole range of old and often odd lenses which look bizarre on modern bodies! Some people enjoy that kind of thing.