ND16: four stops
The ND16 is the filter for shooting video in sunshine. It swallows four stops and stretches the exposure time by a factor of sixteen: 1/125 s becomes 0.128 s. Against an ND8 that is only one stop more – precisely the one that goes missing between 1/100 and 1/50 s once the sun comes out.
- Stops4
- Filter factor16×
- 1/125 s becomes0.128 s
What this strength is good for
- Video on a clear day: The 180-degree rule asks for 1/50 s at 25 fps. An ND8 gets you there under an overcast sky; as soon as the sun breaks through, one stop is missing. The ND16 supplies it.
- Water with a little more calm: 0.1 to 0.5 seconds smooth a creek more than an ND8 without dissolving it into fog. For small cascades that is often exactly right.
- Wide open in sunlight: Four stops bring f/1.8 back into range even around midday. Anyone who shoots wide open in the sun regularly reaches for this before the ND8.
Calculating with ND16
Pick a shutter speed. The fields are preset to ND16.
hours : minutes : seconds : milliseconds
Exposure times with ND16
On the left the speed your camera suggests without a filter, on the right what it becomes.
| No filter | With ND16 |
|---|---|
| 1/500 | 0.032 s |
| 1/250 | 0.064 s |
| 1/125 | 0.128 s |
| 1/60 | 0.267 s |
| 1/30 | 0.533 s |
| 1/15 | 1.1 s |
| 1/8 | 2.0 s |
| 1/4 | 4.0 s |
| 1/2 | 8.0 s |
| 1 s | 16.0 s |
What to watch for
- Tripod past half a second: Up to roughly 1/8 s handheld with stabilisation still works. Past that it does not, and under an overcast sky an ND16 gets there quickly.
- No substitute for a strong filter: Glassy water at the coast or drifting clouds need eight stops and more. Four stops stretch 1/125 s to an eighth of a second, not to minutes.
- A variable ND covers this range: If you work between two and six stops anyway, a good variable ND gives you the same window without changing filters – at the price of a cross pattern at strong settings.
If you mostly shoot video, ND8 and ND16 take you further than ND8 and ND64: together they cover an overcast sky and a clear day.
The other strengths
ND8 · ND32 · ND64 · ND1000 · ND4096
Not sure which strength yet? Which ND filter? works from the subject to the number of stops.
Every value from ND2 to ND8192 is in the ND filter table, and the FAQ answers the common questions.