Originally posted by mikesbike My understanding is the F* version requires both the camera and lens to be switched to MF for manual focusing.
Correct, but not if you are using a manual focus film camera.
I don't own an AF camera, so all my AF lenses are used as MF ones. The F300/4.5 is the best handling AF lens that I have ever used as a manual focus lens and manual focusing the F300/4.5 is way smoother than any FA Series lens I own. (This is probably due to " Pentax's great backwards capability", as the "F" Series were Pentax's first AF lenses and many people who purchased the F300/4.5 used it on a MF film body)
Phil.