Multipoint autofocus is a camera focusing system that employs multiple focus detection points distributed across the image frame, rather than relying on a single central focusing point, to measure subject distance and determine the correct focus for a scene. By sampling focus information from several different locations within the frame simultaneously, multipoint autofocus systems provide more accurate, reliable, and flexible focus acquisition across a broader range of subject positions and shooting situations than single point systems centred on the middle of the frame.
The primary practical benefit of multipoint autofocus is its ability to achieve accurate focus on subjects that are positioned away from the centre of the frame without requiring the photographer to use the focus and recompose technique - the familiar but time consuming process of centering the subject to acquire focus with a single central point and then physically recomposing the shot before making the exposure. Because focus and recompose introduces a slight but potentially significant focus error when the camera is pivoted after focus lock - particularly at wide apertures where depth of field is shallow - the ability to focus directly on an off centre subject using a peripheral focus point eliminates this source of inaccuracy and allows more confident and precise focus placement in compositionally demanding situations.
Multipoint autofocus systems are closely related to and largely overlap in concept with multi point autofocus systems, and the two terms are often used interchangeably in photographic literature and camera documentation. Both describe the same fundamental approach of using multiple distributed focus detection points to improve the accuracy and flexibility of automatic focus acquisition, and both typically offer the option of either automatic point selection - where the camera chooses the most appropriate active focus point based on subject distance and scene analysis - or manual point selection, where the photographer designates a specific focus point to use for a given shot.