field of view (FOV)

Field of view (FOV) is the open observable area a person can see through his or her eyes or via an optical device. In the case of optical devices and sensors, FOV describes the angle through which the devices can pick up electromagnetic radiation.

FOV allows for coverage of an area rather than a single focused point. In virtual reality (VR), a large FOV is essential to getting an immersive, life-like experience. Wider FOV also provides better sensor coverage or accessibility for many other optical devices.

Our eyes are the natural start of perception of FOV. In human vision, the field of view is composed of two monocular FOVs which our brains stitch together to form one binocular FOV. Individually, our eyes have a horizontal FOV of about 135 degrees and a vertical FOV of just over 180 degrees. When the monocular fields of view are stitched together, our binocular FOV gives us around 114 degrees of view horizontally and is necessary for depth perception. Our peripheral vision makes up the remaining 60–70 degrees and has only monocular vision because only one eye can see those sections of the visual field. These measurements are based on the FOV during steady fixation of the eyes.

In addition to monocular and binocular differences in our vision, humans also have different fields of view for different colors. Color saturation and perception is concentrated in the center of our FOV and becomes more monochromatic on the edges or periphery of our vision.

In VR gaming, a simulated environment experienced through the character’s first person view (FPV) is much more immersive with a larger field of view. The limitations of FOV in VR headsets stem from the need to balance the need for lightweight, thinner headsets for better ergonomics against the need for thicker, heavier lenses that require less focal distance to increase FOV. Overly large lenses may also introduce artifacts like chromatic aberration and color distortion.

Drone photography can capture large swaths of landscape better with a larger FOV. Extra visibility can also make it easier to see obstacles in FPV control of drones or when using smartphones or VR headsets.