Field of View Calculator
Calculate the horizontal, vertical, and diagonal field of view (FOV) for a camera or optical system given the sensor dimensions and focal length.
Results will appear here.
Formulas Used
Horizontal FOV: FOVH = 2 × arctan(W / (2f))
Vertical FOV: FOVV = 2 × arctan(H / (2f))
Diagonal FOV: FOVD = 2 × arctan(D / (2f)), where D = √(W² + H²)
Crop Factor: CF = 43.27 / D, where 43.27 mm is the full-frame diagonal (36 × 24 mm)
Equivalent Focal Length: feq = f × CF
Where W = sensor width, H = sensor height, f = focal length, all in millimetres.
Assumptions & References
- The formula assumes a rectilinear (non-fisheye) lens with no distortion.
- FOV is calculated using the thin-lens approximation: FOV = 2 × arctan(sensor_dimension / (2 × focal_length)).
- Crop factor is computed relative to the 35 mm full-frame standard (36 × 24 mm sensor, diagonal ≈ 43.27 mm).
- Sensor presets are approximate industry-standard values; actual sensor sizes may vary by manufacturer.
- Focal length is the effective focal length of the lens as marked (not the back focal distance).
- Reference: Ray, S. F. (2002). Applied Photographic Optics. Focal Press.
- Reference: Smith, W. J. (2008). Modern Optical Engineering. McGraw-Hill.