manualfocus

Manual focus is the technique of adjusting a camera lens’s focus by turning the focus ring until the subject appears sharp in the viewfinder or on the display. It contrasts with autofocus, where the camera uses sensors and motors to select the focus point automatically. Manual focusing is common when autofocus is unreliable or undesirable, such as in low-contrast scenes, dim lighting, macro work, or when using vintage lenses on modern bodies, where precise control over the focus plane is required.

Modern cameras often provide aids to assist manual focus. Live view magnification enlarges the image for fine-tuning, while focus peaking highlights edges that are in focus. Some cameras use focusing screens with microprisms or split-image prisms to aid alignment. Lenses and bodies may also offer manual focus override or tactile feedback through the focus ring to confirm exact placement.

Techniques and concepts associated with manual focus include estimating depth of field and using hyperfocal distance in landscapes to maximize sharpness from near to far. In macro photography, focusing is typically performed at very close distances with careful attention to plane of focus, sometimes requiring frequent refocusing as distance changes. Aperture choice also affects tolerance to focusing error, with smaller apertures increasing depth of field at the expense of light.

Advantages of manual focus include full control and compatibility with older or non-electronic lenses. Limitations involve slower operation, greater difficulty with moving subjects, and the need for steady technique or assistive aids.

See also: focus peaking; hyperfocal distance; magnification.