any canon dslr recs for concert/event photography? hi, i’m kinda an intermediate photographer and i’ve been doing a lot more rave/party/concert/indoor sport photography recently and i really feel like i need an upgrade to my camera body. i’m using a rebel xsi right now, and my main issues are the low max iso (1600), sluggish/inconsistent autofocus, and low burst performance. i’ve been looking in…