What are the One-Shot and AI Servo autofocus modes?
Most EOS cameras support three autofocus modes – One-Shot, AI Servo and AI Focus. Midrange and professional EOS cameras let you choose which mode the camera is in, often via controls marked in yellow. However, low-end EOS cameras do not let you choose these modes directly. Instead, each of the basic modes is preprogrammed to use one of the three autofocus modes. So you can sort of choose your autofocus mode indirectly by choosing a basic mode that happens to have the autofocus mode you want to use. One-shot AF (autofocus). In this mode the camera locks in on your subject and doesn t refocus once you ve achieved focus. It won t take a picture unless you re in focus or unless the lens is in manual focus mode. It s good for shooting static subjects. AI ( artificial intelligence ) servo mode. In this mode the camera tries to keep refocusing the lens as you track your subject. The exposure is determined when the shutter release button is fully depressed in both single and continuous winding
