Camera field of view converter
One spec sheet says 120°, another says 95°, and they might be the same camera. Convert diagonal, horizontal and vertical field of view so you can compare them.
Horizontal
–
Vertical
–
Diagonal
–
How it works
tan(H ÷ 2) = tan(D ÷ 2) × a ÷ √(a² + 1)
tan(V ÷ 2) = tan(D ÷ 2) ÷ √(a² + 1) (a = width ÷ height)
tan(V ÷ 2) = tan(D ÷ 2) ÷ √(a² + 1) (a = width ÷ height)
The angles aren't proportional to the sides of the picture, because the view is a wedge, not a flat rectangle. A 120° diagonal 16:9 camera is about 113° horizontal and 81° vertical, not the 105° and 59° you'd get by simple ratios.
Field notes
- Room planning uses horizontal. Whether the near seats fit depends on the horizontal figure. Run it through the camera coverage calculator.
- Marketing likes diagonal because it's the biggest number. Check which one a spec sheet quotes before comparing cameras.
- Very wide lenses aren't truly rectilinear. Past roughly 110°, many cameras use lenses with barrel distortion or digital correction, so the real usable view can differ from the ideal geometry. Treat the result as a close estimate.
- Digital zoom and auto-framing crop the sensor, which narrows the effective field of view. These figures are for the full, uncropped picture.