Accustomed Wide Angle goals since 1972, having been optics "prestige", super angulon Leica M21mm and R19mm, Distagon 15mm and 18mm Zeiss Contax, fish eye Takumar 17mm, 5.6mm Canon FD, Nikon 20mm and so on Now being retired and no longer having the means to acquire astronomical price objectives (especially since the arrival of the euro ...) I bought this thinking UGA have a "bottle's bottom "... Well no, and I'm very pleasantly surprised! Here are the results, very good correction of vignetting and geometric distortion values (which was not the case for Leica 19mm forming a cocked hat, for optical 19ooo fr ...) Chromatic aberrations are well mastered and with a small processing with Lightroom, everything disappears. Given prices are, it's a good deal, Tamron was right to classify as SP, for the old, remembering the famous Tamron SP 90 macro which referred in the 80s, superior to micro and other nikkor Zeiss 60mm, for a price four times lower!
