Bests & Worsts Reviews from Amazon

I'm a professional photographer[...] and until now, have never owned anything but Canon or Nikon lenses. For years I specialized in sports photography and the lenses I most often used were a 400 f:2.8 and a 600 f:4. I moved on to other fields of specialty and decided I didn't want to lug around that kind of weight and got rid of the big glass. Now, several years later, I decided I needed a long lens again, but in a decidedly smaller package. After trying an unnamed top manufacturer's 80~400 lens and being unhappy with the quality of the image, I dared to try Sigma's new 120~400. I ran the lens through the ringer and tested it under every situation I could think of and through it all, it has performed flawlessly! In fact, I was ready to accept a little less sharpness, so when I evaluated my results, I was thrilled. I highly recommend this lens and I have the utmost confidence in this beautiful package of glass.