Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Photography
Flash Guide Number Calculator
Calculates the correct aperture (or maximum distance) for a manual flash given its guide number and the flash-to-subject distance. Indispensable for manual flash photography without TTL metering.
Fill in the required fields to see your result.
Photography
Field of View Calculator
Calculates the horizontal angle of view in degrees for any focal length and sensor width combination. Use it when choosing a lens for a specific framing or comparing cameras with different sensor sizes.
Fill in the required fields to see your result.
Key differences
| Flash Guide Number Calculator | Field of View Calculator | |
|---|---|---|
| Category | Photography | Photography |
| Inputs required | 2 | 2 |
| Result | Required Aperture (f/) | Horizontal Field of View (degrees) |
| What it does | Calculates the correct aperture (or maximum distance) for a manual flash given its guide number and the flash-to-subject distance. Indispensable for manual flash photography without TTL metering. | Calculates the horizontal angle of view in degrees for any focal length and sensor width combination. Use it when choosing a lens for a specific framing or comparing cameras with different sensor sizes. |