comparing 50-200WR and Quantaray (Sigma) 100-300 at 200mm

I actually won a telephoto bid! A Quantaray open-box deal came to me for a good price, which keeps me from spending $200+ on a long tele that won't get much use - that's a good thing!

First tests with the lens show it to be decently sharp, easily "sharp enough". Its shortcoming seems to be contrast, which makes an image look softer to me than it is. This doesn't look like a problem to me, and with the k-x abilities at higher ISO the slow specs on this lens (f/4.5 at 100-155mm, f/5.6 to 230mm then f/6.7) are less damaging: just set at f/8 and let ISO compensate.