What is SMC-F designation?

SMC-A is manual focus, auto aperture. SMC-FA is auto focus, auto aperture but so (it seems) is SMC-F So what _IS_ SMC-F lens as distinct from SMC-FA? - John Leonard - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't

Opinions on standard zooms

noticed that IF lenses seem to whirr more on focussing. Could the increased load on the camera auto-focus drive be a problem? I'm sure Pentax would say using anything but a Pentax lens might wreck the camera, but what is the truth? Thanks, John Leonard, Surrey, UK. - This message is from the Pentax