Fieldofview

Field of view, often abbreviated FOV, is the extent of the observable world that can be seen at a given moment. It is commonly expressed as an angular measure—horizontal, vertical, or diagonal—or as a linear span at a chosen distance. The term is used across optics, photography, video displays, virtual reality, and astronomy.

In human vision, the field of view is broad, with peripheral vision covering much of the surrounding space while the central retina provides high acuity within a small region a few degrees across. The brain combines information from both eyes to form a coherent scene, but only a small central area carries detailed color and sharpness.

In optics and photography, field of view is determined by focal length and sensor size. The angle of view can be computed by AOV = 2 arctan(d / (2f)), where d is the relevant sensor dimension and f is the focal length. A shorter focal length or a larger sensor yields a wider field of view; a longer focal length or smaller sensor yields a narrower field of view. Distortion and perspective change with wide-angle versus telephoto designs.

In display technologies and virtual reality, the field of view refers to the angular extent visible through the headset or screen. Typical head-mounted displays provide about 90–110 degrees horizontally, with higher-end devices approaching or exceeding 120 degrees. A wider FOV can improve immersion but may introduce distortion and increase hardware demands.

In astronomy, field of view describes the portion of the sky captured by a telescope, eyepiece, or detector, usually given as an angular diameter or in degrees and arcminutes. The FOV depends on optical design and sensor or eyepiece size.