vivitar series 1 are very good zooms, same with the Tokina zooms.
I bought a new(er) Sigma zoom 28-80 and a 100-300 which allow AF and I found them to be very good. I bought those for my Father-in-law K100D and they worked flawlessly, and even came with a MZ-7 for me!
When I think back of all the crappy pictures I've taken, it's a wonder I can see at all......
APX It gives us the nicer grays/It gives the cleanes whites/Makes you think all the world’s a sunny day, oh yeah/I got a nikon camera/I love to take a photograph
MAMA DON'T TAKE MY APX AWAY........
Sorry Paul Simon