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09-22-2012, 09:45 AM   #1
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Location: Leipzig, Saxony, Germany
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Strange aperture behavior with used 17-50mm Tamron


I received today an used Tamron 17-50/2.8 from a Nikon user. He got this lens from eBay thinking it was the right version for him, because it got a Nikon lens cap. Anyway lets get back to topic:

This 17-50 got an strange behavior, it seems to close the aperture not right. f4 is -0.3EV from f2.8, f5.6 -1EV, f8 -2EV, f11 -3EV and so on.

First i thought it would be the blades, who need to much force to close. But checking the lever on the lens manually, resulted in a smooth and easy to control aperture lever. Cleaning the contacts didn't help either.

Does someone here know something about this problem? It didn't seem that popular, because google and forum search resulted only in other kinds of aperture problems.

Your help is greatly appreciated.

09-22-2012, 10:00 AM   #2
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Join Date: Dec 2009
Location: Deep Forest
Posts: 630
Is that a full frame lens on a crop camera?

Full frame lens wide open crop cam meter reads too high.

Besides Manual mode, workaround is to set EV compensation to average value over aperture range used.
09-24-2012, 01:13 AM   #3
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Location: Leipzig, Saxony, Germany
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Original Poster
QuoteOriginally posted by rhodopsin Quote
Is that a full frame lens on a crop camera?
There is no 17-50 who is fullframe capable.

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aperture, aperture behavior, behavior, k-mount, lens, lever, nikon, pentax lens, slr lens, tamron
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