ND32: five stops
Five stops, a factor of 32: 1/125 s becomes just under a quarter of a second. The ND32 is the filter almost nobody buys first and plenty buy second. It sits exactly in the gap between the ND16, too weak for glassy water, and the ND64, which already takes too much away for video in the shade.
- Stops5
- Filter factor32×
- 1/125 s becomes0.256 s
What this strength is good for
- Creeks and small waterfalls: A quarter to half a second is the range where running water turns soft without losing its direction. For woodland creeks under an overcast sky that often beats six stops.
- Video in changing light: There is about one stop between sun and cloud. An ND32 holds 1/50 s across both, where an ND16 is too bright in the sun and an ND64 too dark in the shade.
- Suggesting people in motion: At a quarter of a second passers-by turn into soft outlines without disappearing. If you want a square to look busy without showing faces, this is usually where you land.
Calculating with ND32
Pick a shutter speed. The fields are preset to ND32.
hours : minutes : seconds : milliseconds
Exposure times with ND32
On the left the speed your camera suggests without a filter, on the right what it becomes.
| No filter | With ND32 |
|---|---|
| 1/500 | 0.064 s |
| 1/250 | 0.128 s |
| 1/125 | 0.256 s |
| 1/60 | 0.533 s |
| 1/30 | 1.1 s |
| 1/15 | 2.1 s |
| 1/8 | 4.0 s |
| 1/4 | 8.0 s |
| 1/2 | 16.0 s |
| 1 s | 32.0 s |
What to watch for
- Tripod required from here: A quarter of a second is no longer handheld, stabilisation or not. Without a tripod nothing is left of the gain.
- The unpopular in-between size: ND32 is stocked less often than ND8, ND64 or ND1000, and filter sets usually skip it. If you want one, you go looking for it.
- Stacking is the alternative here: ND8 plus ND4 makes five stops if you already own both. Two more glass surfaces cost a little contrast but save a purchase.
The ND32 is not a first filter. As an addition it closes the gap where the ND16 is too weak and the ND64 too strong – if you own both already, you will rarely need it.
The other strengths
ND8 · ND16 · 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.