Angle of view formula
Use the sensor width for horizontal angle, height for vertical and the diagonal for the diagonal angle, which is the figure most lens makers quote. 43.27 mm is the diagonal of a 36 × 24 mm full-frame sensor.
Full-frame angles of view at common focal lengths
| Focal length | Horizontal | Typical use |
|---|---|---|
| 14mm | 104.3° | Interiors, astro, dramatic landscapes |
| 24mm | 73.7° | Landscapes, environmental portraits, establishing shots |
| 35mm | 54.4° | Street, documentary, natural "storytelling" view |
| 50mm | 39.6° | General purpose, close to human attention |
| 85mm | 23.9° | Portraits, close-ups |
| 135mm | 15.2° | Tight portraits, compression |
| 200mm | 10.3° | Sports, wildlife, stage |
Worked example: blocking a scene
You're shooting a two-person dialogue in a room and the camera can sit 5 m from the actors. On full frame with a 35mm lens:
That's a wide shot showing most of the set. Switch to 85mm and the frame narrows to about 2.1 m wide, a comfortable two-shot. On a Super 35 cinema camera (about 24.9 mm wide), the same 35mm lens frames only about 3.6 m, close to the look of a 50mm on full frame.
Crop factor and equivalent focal length
A smaller sensor records only the middle of the image a lens projects, so it "sees" a narrower angle. The crop factor converts that to the full-frame focal length that would give the same view:
| Format | Crop factor | 35mm lens looks like |
|---|---|---|
| Medium format 44 × 33 | 0.79× | 28mm |
| Full frame | 1.0× | 35mm |
| Super 35 (16:9 area) | ≈1.5× | ≈53mm |
| APS-C (Sony, Nikon, Fuji) | ≈1.53× | ≈54mm |
| APS-C (Canon) | ≈1.61× | ≈56mm |
| Micro Four Thirds | ≈2.0× | ≈70mm |
Crop factor changes the field of view, not the lens's physical focal length. Perspective depends only on where you stand.
Frequently asked questions
What is the field of view of a 50mm lens?
On full frame: about 39.6° horizontal, 27.0° vertical and 46.8° diagonal. On APS-C it narrows to about 26.4° horizontal, similar to a 75–80mm lens on full frame.
Is field of view the same as angle of view?
They’re often used interchangeably. Strictly, angle of view is the angle (in degrees) and field of view is the area covered at a given distance. This calculator gives both.
Why is my lens angle different from the spec sheet?
Manufacturers usually quote the diagonal angle at infinity focus. Many lenses also “breathe”, narrowing or widening slightly as they focus closer.
How do I calculate crop factor?
Divide 43.27 mm (the full-frame diagonal) by your sensor’s diagonal. For a 23.5 × 15.6 mm APS-C sensor, the diagonal is 28.2 mm, so the crop factor is about 1.53.
Last reviewed October 11, 2026. Calculations are estimates. Sun times can vary slightly with terrain, elevation and atmospheric conditions. Found a mistake? Tell us.