The RF 100-500mm f/4.5-7.1L IS USM is Canon’s accessible super-telephoto — L-series quality, manageable weight at 1.37 kilograms, and a zoom range that covers most wildlife and sports scenarios without a second body. The technique that makes it earn that range is not the zoom itself. It is pre-focus combined with burst discipline. Pre-focus means acquiring focus on a known point before the decisive moment, then holding it. A bird banking toward a perch, a runner coming through a gate, a vehicle entering a corner — the trajectory is predictable.