Thank you for all the helpful information. I attempted one time to shoot agility (for practice only) indoors and found I could not get the exposure correct. I was shooting with the 70-200 2.8, but could not seem to get good pictures. Also, it was my first time trying to shoot in that type of environment. May I ask what ISO is used mostly in that type of situation?

Also, would someone be kind enough to tell me what a "crop body" is?

L