How to calibrate a lens on your own?

[ismeticus]

Hi, everyone, I have a Tamron 17-50mm lens, which I am using on Nikon D80 body.

I am not quite satisfied with the lens' autofocus accuracy (back focus). The warranty is voided, and there is no Tamron service center in my country anyway (Kazakhstan). Does anyone have an experience of fine tuning AF by for example rotating some screws inside the lens?

I've already opened the lens before, when the front ring came loose, didn't go deeper inside the lens, but it didn't look terribly sofisticated. When I was tighetening the front ring, I also noticed that front element could be fixed in different positions (closer to of farther from the next element). I tried to play with it by placing in different positions, but didn't notice any difference in sharpness or focus. Does anyone know what is it for?

If someone has any experience in calibrating their lenses, please, share. an advice from someone who worked or works at a tamron service center (or different company) would also be greatly appreciated!

Btw, the lens is tack sharp in manual focus mode!

 

[I Beam]

I suggest you try the Nikon SLR Lens forum.

Are you sure that the problem is with the lens and not the camera?

Regards

Paul

 

[Ring A]

I've heard of adjusting the camera for focus accuracy not the lens.
--
Perseverance breeds success

 

[billou]

I had this lens with a D80.

Produce excellent results when in focus... but I also had focus problems (and overexposure problems when using flash in I-TTL mode).

As the D80 don't have the microadjustement setting I think the only way is to send it to tamron for calibration.

I live in Belgium and was said the price was 200€ (more than half what I've paid for it !) if there was no mechanical failure.

I finally broke the lens (front lens getting loose which I fixed myself and finally zoom ring broke) so never send it in.

That's a pity because when it works it's a really awesome lens...