"A lot of novice photographers don't frame things as tightly as they should," Markewitz says. "It looks right when you're shooting, but the skier comes out tiny. The best way to figure out how tight to zoom is by experimenting-zoom in, step back, whatever-to see what works."
Another challenge is to capture a fast-moving subject at precisely the right moment. "Imagine what the action is going to look like before it happens, and prefocus on that spot. If it's a jump, focus on the air just after the takeoff spot. If you focus on the jump itself, the skier won't have left the ground yet," he says. "Try for halfway between takeoff and landing."
Lenses are another variable. You'll probably be standing a relatively short distance from your subject-maybe 40 feet. "For a good, tight shot, a 200-mm lens is best."