postfocus

Postfocus is a feature in digital photography that allows a photographer to choose the plane of sharp focus after a shot has been captured. It is a form of computational photography that often relies on capturing multiple images or frames at different focus distances, sometimes combined with depth information, to enable refocusing in post-capture.

In practice, a camera or smartphone with postfocus will take a rapid sequence of images or a short burst while varying the focus from near to far. The device then analyzes the set of frames to estimate where the subject is located in depth and presents an interface for the user to select the desired focus point or plane. The result is either a single image with the chosen focus applied or a file that retains multiple focus planes or a depth map for further processing.

Postfocus is commonly marketed as a convenience for macro, product, and landscape photography, where a user may want to reframe and refine focus after the shot. It is important to note that the technique relies on relatively static scenes; moving subjects can produce artifacts or incomplete focus information. The approach may also involve trade-offs in resolution or file size, and it is not a substitute for traditional focusing when sharpness is required across the entire scene.

See also: focus stacking, focus bracketing, refocus, computational photography.