Originally posted by Davo Have a K10D and just purchased Pentax DA 18-135mm. The AF mode doesn't seem to work. Anyone have suggestions as to why?
Hi Davo and welcome.
Ideally your question belongs in the beginners section, but I have an idea so I'll try and help
Do you know what the firmware version of your K10 is? You can find this out by holding down the menu button as you turn the camera on (I don't actually have a K10 but I think this should be universal).
Anyway, apparently support for the silent focusing motors on some of the newer lenses was implemented by firmware part way through the K10's life. Check on the Pentax.jp website to see if there is a newer firmware version and give it a go.
I'm also saying this because I don't think the new 18-135 has support for the 'screw drive' motor. Don't take my words as 100% truth please, I'm just relaying what I have read. But maybe it will get you started.
cheers,
Jason