ND8 exposure conversion#
Meter without the filter, then multiply the shutter time by 8.
| Without filter | With ND8 |
|---|---|
| 1/4000 s | 1/500 s |
| 1/2000 s | 1/250 s |
| 1/1000 s | 1/125 s |
| 1/500 s | 1/62 s |
| 1/250 s | 1/31 s |
| 1/125 s | 1/16 s |
| 1/60 s | 1/7.5 s |
| 1/30 s | 1/3.8 s |
| 1/15 s | 0.5 s |
| 1/8 s | 1 s |
| 1/4 s | 2 s |
| 0.5 s | 4 s |
| 1 s | 8 s |
| 2 s | 16 s |
ND calculator & countdown timer#
What a ND8 filter is for#
ND8 (also sold as ND 0.9 or “3-stop”) is typically used for: Shallow depth of field in bright light, or 1/50 s video shutter in shade.
For video: in bright sun at f/2.8 and ISO 100 you need about 6.4 stops of ND to shoot at 1/50 s (the 180° shutter rule at 25 fps). You would need a stronger filter or to stop down.
Tips: compose and focus before attaching dark filters, cover the viewfinder eyepiece on DSLRs to stop light leaks, and expect a colour cast with strong NDs — shoot RAW and set white balance afterwards.
Other ND strengths#
Frequently asked questions#
How many stops is a ND8?
3 stops — it passes 1/8 of the light (density 0.9).
What shutter speed with a ND8 filter?
Multiply your unfiltered shutter speed by 8. For example 1/125 s becomes 1/16 s.
Last updated October 03, 2026 · How we calculate · Sources