I'm planning on buying a 70-200 2.8 for my kids sports (I have a Nikon D50). I took my 50mm 1.8 to the hockey rink to see if 2.8 would be enough light. I had to crank up to 1600 ISO, and this was the best I could get (I did run it through noiseware). This was through the glass, and normally, I'll be shooting from the bench. Is there anything obvious I'm doing that I could change to get better pictures? Looking at everyone else's pictures on here has made me realize how much improvement I could make. Thanks.