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09-12-2010, 07:28 PM   #1
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Tamron 17-50mm f2.8 horror story

I recently bought a brand new Tamron 17-50 f2.8 Di II, since I wanted a fast lens in that range. All the reviews, and the discussion on this interwebz, had suggested it was a good lens and very sharp.

My first walkabout images with the lens immediately revealed some problems - everything on the left of all my images was soft, and extremely blurry towards the left extremes. However the centre and right side of the image plane was sharp. This was evident at every focal length too. Aha - the lens was de-centred, big time.

Furthermore, the purple fringing exhibited by the lens wide open was HUGE in pixel width and almost impossible to clean-up in PP. And the lens exhibited massive CA on the left extremes, to the point of doubling up any high contrast lines or patterns.

Last but not least, because it was de-centred, the lens displayed very irregular barrel distortion at the wide end. Because the distortion was irregular, it was impossible to correct properly using software - eg in LR3 - even if the software had a lens profile for the Tammy, like LR3 does.

The test pictures below tell the story. Needless to say I've sent the lens back for an exchange. Hopefully the next one the store sends out will be better.

Left side fuzziness:


Irregular wide angle barrel distortion:


Purple fringing from Hell:


None of my Pentax kit lenses in this range ever performed anywhere near as bad as this Tammy. Hopefully it was just a lemon that had perhaps been bumped too hard in transit or something.


Last edited by rawr; 04-01-2011 at 11:49 PM. Reason: Fixed broken image links
09-13-2010, 12:04 AM   #2
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Wow, that does not look good.
The left side blur should be enough to return the lens.
The purple fringing is something that some lenses just suffer from.
Of all the lenses I own, my Tammy 18-250mm is the worst in that respect, however mostly is the smaller apperture ranges.

This is clearly a bad product.

- Bert
09-13-2010, 12:11 AM   #3
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Looks like a bad sample indeed. Return it for an exchange.
09-13-2010, 01:09 AM   #4
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Sorry to hear that. Such is the way with Tamron I have found. When you get a good one, it is really good, but when one is bad - it's obvious.
All the best in the return.

09-13-2010, 01:17 AM   #5
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I humbly suggest immediate return and exchange for another sample...
09-13-2010, 01:19 AM   #6
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Don't be surprised as Tamron lenses are just structurally weak due to the way they were designed and assembled. They could not handle impact (read shipping) as good as some better made OEM lenses. The good news is that the optical alignment of Tamron lenses can be recalibrated (unlike Pentax lenses) at a selected few Tamron service centres, but there is a chance the amount of correction might not be able to bring the optical axis close to perfect. This is a pity because Tamron have designed a few truly fine optics in recent years.
09-13-2010, 04:22 AM   #7
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I bought that lens a couple of years ago and, although I was still a newbie, found it unacceptable. I sent it back and went with the Sigma 24-60mm instead--which turned out to be a very good move.
09-13-2010, 06:56 AM   #8
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I have sent it back and I will see what the 2nd example looks like once I get it. The retailer gave me no hassle about agreeing to take the return. That's good news for them if they want any other future business from me

I was surprised by these problems. Normally I have good luck with lenses, even those I pickup off eBay. I also already have two different Tamron's and both are fine. If the 2nd example of the 17-50 is also a dud I will cut my losses and try something else, maybe the Sigma 24-60 f2.8. It sounds very good.

09-13-2010, 07:06 AM   #9
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I should say I have two other Tammys with which I'm quite pleased. Also, the Sigma 24-60mm has been discontinued and is fairly rare on the used market 'cause them what has 'em keeps 'em.
09-13-2010, 07:17 AM   #10
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QuoteOriginally posted by dadipentak Quote
Also, the Sigma 24-60mm has been discontinued and is fairly rare on the used market 'cause them what has 'em keeps 'em.
Right. Mine has a bit of a focus alignment issue that is resolved by focus correction in my K-7. This is what the seller warned me about. Other than that it is an excellent optic.
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