A good buy

I am a Nikon person, having been a Canon person, but this lens makes one think there is a life worth seeing outside of these mfgrs. I have not been disappointed with this lens yet. I bought it for sports shooting and it has performed better than I could have hoped. Fast focusing and sharp imagery.

I recently got a hold of an EIA1956 test pattern and tested all of my lenses. This is the only non-NIKKOR lens I own. Other than an off the chart results of my Nikkor 60 MM, this lens equaled my Nikkor 80-200MM f2.5, Nikkor 28-85, or Nikkor 35-70 in terms of resolution from test shots

I found the best results at zoom MM of 195 at f 5.6, but the whole range of f 5.6 to f 11.0 was good. The middle zoom range seemed to be the best.