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.
Optics
Depth of Field Calculator
Compute the total depth of field for any camera and lens combination using focal length, f-number, focus distance, and circle of confusion. Use it to plan sharp focus zones before a shoot.
Fill in the required fields to see your result.
Key differences
| Flash Guide Number Calculator | Depth of Field Calculator | |
|---|---|---|
| Category | Photography | Optics |
| Inputs required | 2 | 4 |
| Result | Required Aperture (f/) | Depth of Field (mm) |
| 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. | Compute the total depth of field for any camera and lens combination using focal length, f-number, focus distance, and circle of confusion. Use it to plan sharp focus zones before a shoot. |