@woosh/meep-engine/src/engine/graphics/ecs/camera/focal_length_to_fov.js

Pure JavaScript game engine. Fully featured and production ready.

/**
 * @see https://en.wikipedia.org/wiki/Focal_length
 * @param {number} focal_length (in mm)
 * @param {number} [sensor_width] Width of camera sensor (in mm)
 * @returns {number} in Radians
 */
export function focal_length_to_fov(focal_length, sensor_width = 35) {

    return 2 * Math.atan(sensor_width / (2 * focal_length));

}