Originally Posted by Sinh Nhut Nguyen
I know how you feel. I was at a horse show a few weekends ago, using my 70-200mm f/2.8L IS, when I noticed a guy with a honking-big white lens on a tripod. It was a 400mm f/2.8L IS (cost: $6,800). He said that it was really too long for that venue--the 300mm f/2.8L IS (only $4,100) would have been better, but he doesn't have the 300mm. Anyone who does have both of those lenses is a pro, stinking rich, or a true fanatic. (Bryan, are you listening? [] That guy was not a pro, but he said that he does shoot a lot of sports. There were a lot of 70-200mm f/2.8L lenses around. Some, I could tell, were IS verisons. One woman had a 1D--can tell by the sound!--with the 70-200mm f/2.8L IS--on a monopod. I'm not sure why the monopod. (I didn't ask her.) The IS will take care of most camera shake and, anyway, the shutter speeds one needs to use to stop the horses' motion would be high enough to get good shots. I did see some of her shots, over her shoulder, sort of, on her laptop. They were all underexposed by 2 stops or more--thus, her shutter speed was even higher. She said that she could "fix that" in Photoshop.
One problem I've noted with monopod users is that a lot of them end up tilting the camera without realizing it as they follow the horse. There is a way to prevent that, but that's for another topic.