[Brisboy]

Greetings all, I just picked up a Pentax f 80-200 on Ebay and am having trouble with the camera (a k-x) recognising it as an af lens. When I put it on the camera it asks me to input the focal length as though it were a ka mount lens rather kaf. The camera aperture control works fine but it won't focus. Any bright ideas?

[Brisboy]

The af linkage between camera and lens engages by the way.

[rbefly]

Hello Brisboy,
I don't know for sure, but here's what I'd try. With the camera switched on and the lens mounted, turn the AF/MF switch to manual focus and run the focusing ring all the way from infinity to close-focus and back again, by hand. Turn the camera off, switch back to A/F, turn the camera on again, see if A/F works. Sort of like cycling it, in case it's stuck.
Second, clean all the contacts on the lens rear and the camera bayonet.
Last, double-check all the camera menu-focus settings, just in case something got input by mistake. I know it's unlikely, but it's worth a look!
That's all I've got, good luck!
Ron

[tom1803]

Try cleaning the contacts, both on the lens and the camera.

If that doesn't solve the problem, then I would suspect that the lens is faulty. Most likely a fault with the contacts on the mount or the internal forked spring contact that relays the focal length info.

If cleaning doesn't work, send the lens back to the seller for a refund.

[Brisboy]

Thanks, both of you. I'll give that a go this evening and see how we go.

[Brisboy]

Thanks for the help. No luck unfortunately. Waiting to hear back from the seller. I took the mount off as well and couldn't see anything obviously out of place.

[tom1803]

Hmmmm .... I hope you were able to put all the bits back together again properly and pray that the seller doesn't read this thread. The seller could easily refuse any refund or compensation by claiming that you tampered with the lens.

If you intend to return any purchased item for a refund or credit, you should always do so under the criteria that the item is in the same condition as you received it.

[Brisboy]

Thanks tom1803, I understand that and I've let the seller know what I've done. It has the same functionality it had before. I'm not super concerned about the refund as I got it cheap. I'd rather have a crack at getting it to go and maybe succeed than wonder whether or not I could, hence this thread.