I have this goal since January 2009, mounted on Nikon D300, I must say that I am completely bleuffé the outstanding quality of this super wide-angle zoom, and over the entire focal range. Vignetting is invisible to the naked as chromatic abberation eye distortion is present but normal for this kind of stone. In short a very good job of that optical engineers at Tamron are made there! I recommend it to all who want to see their environment differently.