Tokina 10-17mm Problem

I have a strange problem with my Tokina 10-17mm - where I am getting inconsistent exposures. Here is an example from yesterday.

Both these images were taken on Manual. F11 @ 1/100th. ISO 100. Strobes on manual too. Under the same environmental conditions. Yet you can see very different exposures (both in foreground and background areas). I realise that neither is very good exposure. My concern is the difference, when there should be none. The right hand image is what I would expect from these settings in these conditions.

I have had this problem just a couple of times with the lens. And on both my D2X and in the case above my girlfriend's D80. So I don't think it is camera related.

The only difference has been in the orientation of the camera. These were taken with camera different ways up.

I suspect that the problem is a communication one between the lens and camera body, aggravated by certain camera orientations. I had this problem on my D2X when shooting vertically up. One possiblity is that the lens is not stopping down properly - although the depth of field looks very similar in these two images - hard to judge. Maybe a sticking aperture? This is a G-Type lens, by the way (Nikon speak for no aperture ring).

Anyone got any ideas on the cause. Contacts look clean.

At present the problem is very rare. 1 in 1000 shots or so. But I'd like to know the cause and remedy. Also as this is a popular lens here I thought it would be useful to share my concerns.

Also does anyone know a contact for repair/servicing for the Tokina in the UK?

Thanks

Alex

This is sad, but I have had similar problems with a Tokina lens in the past, and no-one seemed to know who would fix it. The problem was mechanical in mine, progressed to total failure, and I junked the lens. It left me so suspicious of Tokina, that I have resisted the urge to use the 10-17, despite its excellent press.

Tim

Hi Alex,

I had a similar problem years ago with my Nikon 35mm/f2 lens where it would occasionally overexpose a shot a by a couple stops--turns out the aperture was sticky. sometimes oils leak out and get on the blades making the diaphragm fail to fully stop down to the correct aperture. a simple servicing fixed it although I had to do it twice b/c the first repair shop did a poor job.

cheers

Kyle

Check the lens diaphram isn't sticking, I've had this happen on a lens in the past. Also, check that you don't have any controls partially compressed on your housing when this is happening - although I suspect you have checked that e.g the mode and exposure compensation dials.

check the aperture 'fin' on the lens mount. its the little lever that connects to the camera allowing the camera to control the aperture. you can move it and watch the aperture open & close.

I once bent the fin on my 300/2.8 and kept getting overexposed shots cause the fin wasn't engaging with the camera control properly. This was likely due to mounting the lens in a hurry and knocking the fin out of place. I compared it to my other lens mounts, and it was noticably bent.

So with a very nervous/sweaty/shaky application of a pair of pliers got it bent right back into shape and it's worked great since. It started as an occasional oddity and eventually became full-on. Hope this helps. Cheers,

Chris

Thanks for all the feedback, guys.

Alex

Care to speculate when Nikon will move entirely to electronic aperture and focus control?

Not sure. Pretty much all their lenses now are G only - electronic only. But the all but the basic SLRs - D40 do not offer compatibility with old manual lenses. So it will be a while yet.

Alex

Do you guys use a diopter with this lens?

There is no provision to fit one on this lens as far as I am aware. The front element is curved and has no thread.

Never had a focus problem with mine - only quite a dose of CA!

Paul C

Thanks prc