HOW IT IS CALCULATED
Calculate ND filter strength
0.008 s → 8 s is about 10 stops
Instant resultClear formulaRuns locally
01Values
02log₂(target shutter ÷ base shutter)
03Result
0.008 s → 8 s is about 10 stops
ND strength is logarithmic
Doubling exposure time corresponds to one additional stop.
02
In short
What logic does the calculator use?
log₂(target shutter ÷ base shutter)
Example?
0.008 s → 8 s is about 10 stops