"John Whittingham" <[EMAIL PROTECTED]> wrote: >> i've been thinking over Bruce's comments and i think i do the same >> thing. i mount the lens with the body in AF mode and twirl the focus >> run until it locks. the lens is usually in MF mode, but it may work >> in AF mode too, depending on the lens. > >OK I've had a play. If you mount the lens on the camera in AF it works >perfectly well, if you then switch to MF and re-focus when you switch back to >AF there's no response...............until you manually focus the lens >accurately on the subject then if you switch back to AF it works perfectly >again. All this is with the camera body set on AF, the 24mm f/2 works fine no >matter what. It's driving me nuts 8-)
Unless I'm not understanding your description, all my AF lenses behave this way. When you manually focus you turn the AF coupling drive (if you manually focus with the lens not mounted on a camera you can see it turn). Every 180 degrees of rotation it will be lined up with the drive coupler in the camera. If it isn't close enough to lining up (and statistically, it often won't be) then it, well, won't line up and couple. Shifting the focusing ring slightly takes care of this. -- Mark Roberts Photography and writing www.robertstech.com
