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Friends have hired me to get some action shots of their son, who is the center on the high school football team, since this is his senior year. 1. Which lens would you recommend for reaching from the sidelines to the center of the field? 2. Which settings would you recommend to carry me from late evening to night with stadium lighting? I currently have a Canon 7d and shoot weddings and family portraits on the beach....so I'm venturing into unknown territory here! Thanks!