Flash Exposure Calculator

Calculate flash exposure settings using guide number and distance.

Number of items or instances.
m @ ISO 100
Linear measurement between two points.
meters
Enter the iso value for this calculation.
ISO

Results

Required Aperture:
Value expressed as a rate (per unit).
-f-stop
Effective GN at ISO:
Calculated effective gn at iso based on your inputs.
-
Max Distance at f/2.8:
Maximum allowed or calculated value.
-meters
Reference: Industry Standards.