Focus & Depth of Field

Face Detection

A system that identifies human faces in the frame and prioritises them for focus and often for exposure.

Focus

The condition in which light from a point on the subject converges to a point on the sensor, rendering that part of the scene sharp.

1/f = 1/u + 1/v m

Focus & Depth of Field

Focus and Recompose

The technique of focusing with a central point, locking, then shifting the camera to place the subject elsewhere in the frame.

Focus & Depth of Field

Focus Bracketing

An in-camera function that automatically shoots a sequence of frames at incrementally different focus distances.

count

Focus & Depth of Field

Focus Breathing

A change in a lens's angle of view as it is focused, so the framing appears to zoom slightly during a focus pull.

%

Focus & Depth of Field

Focus Confirmation

An indicator, usually a dot or the illumination of an AF point, showing that the camera considers focus achieved.

Focus & Depth of Field

Focus Limiter

A switch that restricts a lens's focusing range, so autofocus does not search through distances the subject cannot occupy.

m

Focus & Depth of Field

Focus Lock

Holding the current focus distance so that further movement of the camera or subject does not trigger refocusing.

Focus & Depth of Field

Focus Magnification

A function that enlarges part of the live image so focus can be judged at a pixel level.

× magnification

Focus & Depth of Field

Focus Peaking

A display aid that outlines the highest-contrast edges in the live image, marking what is currently in focus.

Focus & Depth of Field

Focus Priority

A setting that prevents the shutter from firing until the camera confirms focus has been achieved.

Focus & Depth of Field

Focus Shift

A movement of the plane of sharpest focus as a lens is stopped down, caused by residual spherical aberration.

mm

Focus & Depth of Field

Focus Stacking

Combining several frames focused at different distances into one image with depth of field no single exposure could achieve.

count

Focus & Depth of Field

Focus Throw

The angle through which a focus ring must turn to travel from minimum distance to infinity.

degrees

Focus & Depth of Field

Focus-by-wire

A manual focus ring that sends an electronic signal to a motor rather than moving the optics mechanically.

Focus & Depth of Field

Front Focus

A calibration error in which a lens consistently focuses slightly nearer than the intended subject.

mm