Angle of View

This formula gives the angular width of the scene that fits across a camera sensor for a given focal length. It comes from simple pinhole-camera geometry: the sensor half-width and focal length form a right triangle, so half the angle of view is arctan(d/2f), and doubling it gives the full angle. Larger sensors increase the angle of view, while longer focal lengths narrow it.

Use this when you want to predict how wide a lens will frame a scene on a specific sensor, such as choosing between wide-angle, standard, and telephoto options. It is also useful for comparing cameras with different sensor sizes or for matching the field of view between systems.

• Using the sensor diagonal when the formula calls for a specific sensor dimension like width or height
• Forgetting to divide the sensor dimension by 2 before taking arctan
• Mixing up degrees and radians when reporting the final angle