☀️ ND Filter Calculator

Find the right neutral density filter for long exposures — silky water, light trails, and dramatic skies.

Shutter Speed Converter

Current Shutter Speed

Target Shutter Speed

Filter Stacking Calculator

Combine two ND filters to achieve more stops of light reduction.

ND512

9 stops combined

ND Filter Reference

Filter	Stops	Factor	Best Use Cases
ND2	1	2×	Slight overcast reduction, video frame rate control
ND4	2	4×	Bright sky portraits, slight motion blur in water
ND8	3	8×	Waterfall blur in daylight, reduce depth of field
ND16	4	16×	Moving clouds, rivers in overcast light
ND64	6	64×	Silky waterfalls, remove people from scenes (crowded places)
ND400	~9	~400×	30–60s exposures in daylight, glassy water
ND1000	10	1000×	Long exposure seascapes, light trails, steel-water effect
ND32000	15	32000×	Extreme long exposures, daytime 5–10 minute exposures

How ND Filters Work

Neutral Density (ND) filters are dark glass or resin filters that reduce the amount of light entering the lens without affecting colour. This lets you use slower shutter speeds, wider apertures, or higher ISO in bright conditions.

Each stop of ND halves the amount of light. An ND1000 (10 stops) lets in 1/1000th of the available light, turning a 1/250s exposure into a 4-second exposure.

The naming convention varies by manufacturer. ND factor (ND2, ND4…) is the optical density multiplier. Stops = log₂(factor). Some brands use optical density notation (0.3 = 1 stop, 3.0 = 10 stops).

Filter stacking is additive in stops — an ND64 (6 stops) + ND8 (3 stops) = ND512 (9 stops). Note that stacking can introduce vignetting and colour casts on wide lenses.