Prefocusing
Focusing in advance on the spot where the subject will be, then firing as it arrives.
Measured in
m
In depth
Prefocusing sidesteps autofocus entirely when the action is fast but the location is predictable — a finish line, a jump, a doorway. It also solves cases where autofocus would fail, such as a subject that appears too briefly to acquire or a scene shot through glass. The technique demands anticipation rather than reaction.
Examples in practice
Focusing on a puddle and waiting means the shutter can fire the instant a cyclist enters, with no acquisition delay.