Tokina 20-35 2.8 help

[statebirdme]

Hi, I just purchased a tokina 20-35mm 2.8 lens and I can't seem to get it to autofocus by itself....the ring is up to the autofocus setting but it doesn't autofocus..any suggestions?

[another view]

Is this one of the lenses where you push/pull the focus ring to switch from auto to manual focus? It sounds like it is, and you've checked that - easy enough to bump it from AF to MF and not realize it right away, especially with a wide angle lens.

What camera are you using? Have you checked to make sure the camera in an AF mode?

[statebirdme]

Yeah it is one of those type of lenses...I try pushing or pulling it to the AF or to MF but it doesn't go to either and when I try to focus it it sounds like its rotating but after a second of focusing it sounds like it clanks and hits something...I'm using a Nikon D50 and yes I have the camera in an AF mode

[Xia_Ke]

I'm not sure if this is one of the lenses effected but I had the Tokina 20-35mm 3.5-4.5 and there is a compatibility issue with D50's. It worked most of the time but, sometimes would quit for no reason and I would have to take off the lens and turn off my camera. In reading about it, a couple Tokina lenses had this issue and it was only with the D50. From what I found out at the time, they could be sent in to Tokina to have the chip replaced.

[statebirdme]

Does this cost anything to get the chip replaced? I'm not even sure if the autofocus mechanism works to be honest....Is there any way I can tell for sure if the autofocus motor is the problem?

[Xia_Ke]

Does this cost anything to get the chip replaced? I'm not even sure if the autofocus mechanism works to be honest....Is there any way I can tell for sure if the autofocus motor is the problem?

I'm not sure The rechipping I read about on another forum after some google searching. I considered it a minor inconvenience so I never bothered to find out more. You can try contacting THK Photo which is the US distributor for Tokina. Their info number is 1-800-421-1141.