I had been researching the Sigma 17-70mm f2.8-4 DC Macro OS HSM lens which I considered buying, I put a thread on the similar Tamron offering to see if anyone had much experience from AP on the similar Tamron lens, not much joy for a Canon mount.
The reviews I could find on the Tamron were fairly "blistering", so I though of trying the Sigma and its reviews weren't much better. Finally bit the bullet and ordered the Sigma
There were remarks like: "performance at 70mm is comparitively poor", and "images with the lens stopped down below f4 showed de-centred results", CA is not too bad but barrel distortion is pronounced at all shorter focal lengths and at 70mm there is bad pin-cushion?
I put the two above images in to say that my untrained eye can't see any of the poor results which the "independent reviewer" was writing about? Both images were shot hand-held, the first at 1.125 sec and the second at f3.2 and 1/1000 sec. ISO in both is 100 taken with a Canon 7D.
The shot of the wheel was taken at a wide aperture to try to detect the "significant degradation" at the corners of the image
What do you guys think, or am I totally mad????