09-22-2010, 09:22 PM
I have an exposure issue with my Tamron 60 f/2 as well. When I first got it, I saw no underexposure except when I set it wider than f/2.8. I ran some tests and found that the camera is misreading what aperture the lens is set to. When I set the f-stop on the camera to 2.8 the lens was actually at 2.2 (and the camera exposed correctly for f/2.2, when I first got the lens). When I set the lens to 2.2, it was still at 2.2 but the camera exposed correctly for 2/3 of a stop ABOVE 2.2, so I got underexposure. I never had problems at any other apertures, even wide-open at macro distances where the maximum f-stop is lower.
Recently I've had to set the exposure to +0.7 to get accurate metering, which is apparently a common problem. I think the aperture lever became loose.
What I think is going on is that Tamron is not good at calibrating the aperture lever on the mount to the camera. That's the problem with the mechanical aperture control on Nikon cameras, compared to electrical aperture control on Canon cameras. I've never read a report of Tamron lenses systematically underexposing on Canons. I hope that Nikon eventually makes aperture under electrical control to get rid of these ridiculous problems. That will give them one more reason to charge extra for higher-end bodies <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
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Recently I've had to set the exposure to +0.7 to get accurate metering, which is apparently a common problem. I think the aperture lever became loose.
What I think is going on is that Tamron is not good at calibrating the aperture lever on the mount to the camera. That's the problem with the mechanical aperture control on Nikon cameras, compared to electrical aperture control on Canon cameras. I've never read a report of Tamron lenses systematically underexposing on Canons. I hope that Nikon eventually makes aperture under electrical control to get rid of these ridiculous problems. That will give them one more reason to charge extra for higher-end bodies <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />