ND Filter Calculator
Calculate the exposure adjustment needed when using neutral density filters. Enter your base exposure and filter strength to get the corrected time.
Calculate exposure
Enter your metered exposure and select your ND filter
Enter time in seconds or mm:ss format
Quick reference table
Common exposures with different ND filters
| Base | ND2 | ND4 | ND8 | ND64 | ND1000 |
|---|---|---|---|---|---|
| 1/500s | 1/250s | 1/125s | 1/60s | 1/8s | 2s |
| 1/250s | 1/125s | 1/60s | 1/30s | 1/4s | 4s |
| 1/125s | 1/60s | 1/30s | 1/15s | 1/2s | 8s |
| 1/60s | 1/30s | 1/15s | 1/8s | 1s | 15s |
| 1/30s | 1/15s | 1/8s | 1/4s | 2s | 30s |
| 1/15s | 1/8s | 1/4s | 1/2s | 4s | 1m |
| 1/8s | 1/4s | 1/2s | 1s | 8s | 2m |
| 1/4s | 1/2s | 1s | 2s | 16s | 4m |
Understanding ND filters
Neutral density filters reduce the amount of light entering your lens without affecting colour. They're named by their optical density or light reduction factor:
- ND number = light reduction factor (ND8 reduces light by 8×)
- Stops = log₂ of the factor (ND8 = 3 stops, because 2³ = 8)
- Optical density = log₁₀ of factor (ND8 = 0.9 OD)
Use ND filters to achieve longer exposures for motion blur, wider apertures in bright conditions, or to balance exposure in high-contrast scenes.
Calculate reciprocity compensation for long exposures with Silverlog
Coming soon