🔭 Focal Length Calculator

Focal Length and Field of View

Field of view (FOV) is determined by focal length and sensor size using the formula: FOV = 2 × arctan(sensor_size / (2 × focal_length)). A shorter focal length gives a wider FOV, while longer focal lengths produce a narrower, more telephoto view.

Sensor Size Matters

The same focal length produces different FOVs on different sensor sizes. A 50mm lens on full frame (36mm sensor) gives about 39.6° horizontal FOV, but only 27.0° on an APS-C sensor (23.5mm). This is why crop factor affects the effective field of view.