9 out of 10 points and recommendedSharp at wide anglesoft at 22mm
One of my favorite lens. I use it for making spherical panoramas at 10mm mostly. It is very sharp at all focal length up to apr.20mm and soft at 22mm, but who cares.reviewed May 8th, 2011 (purchased for $650)
I also tried sigma 10-20mm, but Canon was better in my test.
3 out of 10 points and not recommended2.8 apertureDecentering defects
I had Tamron 18-200 for a long time and it was nice. I expected to have a nice lens when bought this 17-50.reviewed May 8th, 2011 (purchased for $500)
This lens can be sharp, I'm sure. But I've got a sample with huge decentering defect. I tried to change it to another, but it had similar problem. Only the third was symmetrical, but I was too disappointed. I don't like this lens, and had sell it at last. I don't recommend it. QC is poor at the factory. Try it carefully before buying.
Hello from Moscow.