Tokina 11-16DX

<p>As I posted in a thread below, I bought a new Tokina 11-16 Pro DX lens for my D300s. I really like the lens and have already got some really neat wide angle shots with it just in testing it out. I can see leaving this lens on my camera a lot. It seems very sharp at every focal length from center to corner, and not surprising is very well made. It does vignette at 11mm and f2.8, but that's to be expected. Flare is very well controlled with the lens, which kind of surprised me given some reviews I had read. </p>

<p>The only issue I'm having is with exposure, and I don't know if it's because of the lens or my camera in how it communicates with the lens since it's not a Nikon. It seems shooting at 11mm at F8 (aperture priority/matrix metering) the exposure is about right. However, as I zoom in towards 16mm, maintaining the same aperture, the image gets progressively brighter, and at times may overexpose by 1 f-stop or more. The same issue occurs when I open up the aperture. If I open up the aperture from F8 to f2.8 shooting at any focal length, the image also gets progressively brighter instead of staying constant. I was wondering if anyone else has seen this from this lens or from the Tokina 12-24? I used to have a Tokina 12-24 and I remember it overexposing a lot as well, I just don't remember the focal length or aperture having anything to do with it. Of course all I have to do is adjust the exposure if needed, which isn't a big issue in shooting landscapes since I'm usually not in a hurry. I don't like returning things and I'm hesitant to have B&H exchange it since the lens otherwise seems okay, and not knowing if the problem is with the lens or my camera, but I wanted to get your thoughts. Certainly, if I knew I could exchange it for one that doesn't have an exposure issue I would.</p>

<p>I'm not one to tell someone how to adjust their camera, but if I'm understanding correctly, your image should get brighter if you open your aperture from f/8 to f/2.8. As far as it getting brighter set f8 and just zooming from 11mm to 16mm, that does seem odd. Is the shutter speed changing as you zoom? or even the ISO? Try in manual priority and see what happens.</p>

<p>Kyle, all the settings stay the same when zooming in. Now I suppose it could get brighter when I zoom in on a scene because there is less bright sky the more I zoom, so more of the metering is from the darker (non-sky) part of the scene. I'll try tomorrow to see what happens in manual mode, or when I'm shooting a scene without a bright sky. </p>

<p>I just checked my 11-16 (the first version, not the current one) on a D300 and I don't see a bothersome variation when changing focal length at f/8. Apparently, early version of the 11-16 had that problem: http://www.flickr.com/groups/tokina11-16mm/discuss/72157614018050086/ which was correctable by sending the lens in to THK. I assume that you have the current version; I haven't read about any issues with it and would suggest you return it. What you describe sound like the aperture isn't at the values were it is supposed to be.</p>

<p>Thanks Dieter. It really doesn't seem right but I'm going to check it again tomorrow, this time shooting at a subject where the light is the same even as I zoom in. If it still overexposes as I zoom in or open up the aperture, I'll have B&H exchange it. It's the original version of the lens, not the newer version with the built in AF motor.</p>

<p>I read all the posts in the link you posted, and it sounds like the very same issue I'm having with mine. Looks like I'll probably be sending it back. :(</p>

<p>If you do not change the framing, the exposure value should stay the same indeed. My Tokina 12-24 with matrix metering on my D300 was always a bit on the "wild side"; reframe a bit and the exposure would shift with several stops - but this was independent of the FL or aperture chosen, purely how matrix metering and wide angle did not seem to like one another. Using Centre-Weighted or Spot metering, it was consistent.<br>

So, for testing purposes, do use spot metering, meter on a point that will not change as you zoom in or out, and then run the tests. That should show whether the lens behaves as it should.</p>

<p>Just another 2p's worth. Vignetting can look very similar to underexposure, and conversely, can affect the metering of the camera. I would expect a zoom at its longest FL setting to show less vignetting and hence look quite a bit brighter.</p>

<p>I also believe that some cameras will automatically correct vignetting during file processing, provided the lens in recognised by the camera. 3rd party lenses will (unsurprisingly) often be missing from that list of 'approved' lenses.</p>

<p>I tested more today and it clearly overexposes at 16mm vs. 11mm. I tried it using matrix and spot, and it does the same. I attached pictures of my yard, where the lighting would be the same whether at 11 or 16, just to show the difference and how it overexposes at 16. </p><div></div>

<p>Here it is at 11mm:</p><div></div>

<blockquote>

<p>I would expect a zoom at its longest FL setting to show less vignetting and hence look quite a bit brighter.</p>

</blockquote>

<p>Had been my first thought too - but the 11-16 has about 1/2 of a stop variation at the different focal lengths at f/2.8 - and much less for the other apertures.</p>

<p>There is about a 1 stop variation going from f/2.8 to f/4 (or beyond) at 11mm - but that's not what the OP is seeing.</p>

<p>I just went outside and did the same test that Mike did - at f8, the shutter speed was 1/125 for both focal lengths, yet at 16mm the image is about 1 stop over-exposed (highlight are actually blown). The effect is less at f/4 and absent at f/2.8. Looks like my lens has the same issue - quite remarkably that I hadn't noticed it so far :-(.</p>

<p>Can't say that it bothers me though - I am dialing in exposure corrections all the time anyway. I doubt that exchanging the lens will get you one without the same issue - inquiring with Kenko/Tokina USA, Inc. might be more helpful. http://www.kenkotokinausa.com/contact/ Since the lens is not yet discontinued, it should carry a 3-year warranty (which wouldn't help me since I got the lens in 2009 ;-()</p>

<p>Just to bring some closure to this thread, I went out today and did a lot of shooting with the 11-16DX and now I'm wondering how I ever got by without this lens before. I don't think the exposure variation is going to be a big issue at all in real world shooting. This is a beautiful lens. </p>