ND Filter Calculator

Find the new shutter speed after fitting a neutral-density filter. Pick a common filter or enter the number of stops, and read off the long exposure time.

New shutter speed
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An ND filter blocks light so you can use a longer shutter for motion blur in daylight. Each stop doubles the exposure time, so a 10-stop filter multiplies it by 1024. Pick a filter or enter the stops directly.

Frequently asked questions

How does an ND filter change the shutter speed?

Each stop of ND doubles the exposure time. The new shutter speed is the base speed times 2 to the power of the stops. A 10-stop ND turns 1/100s into about 10 seconds (1/100 times 1024).

What stop value does each ND filter have?

The ND number is roughly 2 to the power of the stops: ND8 is 3 stops, ND64 is 6 stops, ND1000 is about 10 stops. Pick the filter from the list and the stops fill in, or type your own.

Can I stack ND filters?

Yes. Stacked filters add their stops, so an ND8 (3 stops) plus an ND64 (6 stops) gives 9 stops. Enter the total stops to get the combined shutter speed.