I could not decide long ... Should I take the cheaper Sigma OS or Tamron? I fortunately had the opportunity to pit both lenses directly to today. At aperture 8, the two lenses do not take much! But who photographed with such a lens exclusively with f8? Because I can buy a cheaper 70-300 me. The images of the Tamron are a dream at f2.8! While the Sigma works here very soft and dull, stands the Tamron out with an excellent image quality. The higher price is justified in any case and also the housing acts no less than that of the Trivalent Sigma. The stabilizer of the Sigma seems to me a little quieter, the AF is however the Tamron slightly faster. You also get used to the relatively high weight :) I take pictures with the 70-200 (yet) on a D5100 together with a Sigma 17-50 OS and a 1.8 / 50th
