Using older Pentax lenses

I've just bought a K20D, and I'd appreciate advice on using older (non-A) lenses with it. I've got quite a collection, back to screw-mount lenses (Rodenstock, Angenieux), and I'm reluctant to give them up.

You can use them if you activate the custom menu item "permit use of aperture ring" and then use stop down metering in manual or aperture priority.

If you do a search on this forum you will find lots of threads covering the details in great depth.

The lenses are definitely worth using, they will just be a little less convenient than A lenses and later.