Summary: I purchased this lens 2 months ago and was very excited to receive it. Unfortunately my excitement was short lived as this lens was mediocre at best. Don't get me wrong, it was an upgrade over the Sony 18-55 kit lens but I had a hard time warranting the $400 price tag for what I was receiving optically. I regretted not saving the money and purchasing the Sony 16-50 2.8.
Summary: I have owned two versions of this lens Canon and Sony. The copy of the lens I used with the Canon gear was pretty good. A little veiling haze and so-so contrast at F2.8 but livable and correctable in post. All other apertures it was pretty good! If you are a Canon user this is an excellent lens for the price. However I sold up my Canon kit to move to Sony.
Excerpt: This is my first Tamron and also my first business with Adorama. The lens was delivered a day earlier than promised. I used it on my D7000, try to take the advantage of a $75 coupon offer. It's the version with built-in motor. Its focusing is quick enough, just like the speed of my beloved Nikon 18-200 and the noise is bearable. But it has too strong back focus from 17mm to about 35mm, rendering this lens almost unusable at wider apertures within this range.
Excerpt: I have to give this lens a low rating only because of quality control. My copy of this lens has a severe front focus problem. In manual focus the image is very very sharp, but auto focus misses every time. B&H was not helpful in letting me swap the lens. I was told it was my problem, and to contact Tamron for service. I have used a very sharp working copy of this lens, and if you get one that works it is a great lens. Unfortunately I didn't.
Excerpt: My wife bought one of these lenses for her EOS 60D. After testing we found it a wonderful lens: lightweight, fast focusing, excellent sharpness and very little chromatic aberration.After I traded my EOS 1Ds for a 60D last weekend I ordered another Tamron 17-50/2.8 for myself. After receiving and testing it this afternoon I decided to return it immediately. Nothing in the frame is sharp, even at 35mm and f/8 using a tripod. The chromatic aberration is terrible.
Summary: I desperately wanted to like this lens, since I currently can't afford a Nikon equivalent. Plus, the reviews were great, especially on SLRGEAR.COM. I just finished tests on a resolution chart. On a tripod, with a D300s and using Live View magnified to focus manually. Wide open at 50mm, this lens is useless. Worse than the few kit lenses I've tested. The center is not great, but the fall off in acuity away from the center is fast and horrendous.
Excerpt: I bought this lens instead of the Sigma 17-50mm f/2.8 because I thought it was sharper... what a deception. This lens is not sharp and it's construction is terrible, it's weak and mine have a lots of spots of dust inside and are impossible to remove. I wanted other Tamron lenses, but now I'm very disappointed with this brand. I recommend you to bought the Sigma one or the Pentax.
Excerpt: Its kind of hard to give right amount of star to this lens. I have a D90 Nikon camera, taking pics of nature, landscape , portrait and weddings. I wanted a better mid-range lens then the lenses that I am already have(50mm/f1.8 and the kit lens 18-55/f3.5) I did lots of research and testing on this lens and I found out that this lens is not calibrated very well with Nikon cameras. 5 out of 30 pics were blurry/out of focus/overexposed.