ND Filter Calculator
Calculate the adjusted shutter speed when using an ND filter. Enter your base exposure and filter strength to see the new shutter speed.
New Shutter Speed
8.2s
= 8.19 seconds
+10 stops of light reduction
ND Filter Reference
| Filter | Stops | Optical Density | Light Reduction |
|---|---|---|---|
| ND2 | 1 | 0.3 | 1/2 |
| ND4 | 2 | 0.6 | 1/4 |
| ND8 | 3 | 0.9 | 1/8 |
| ND16 | 4 | 1.2 | 1/16 |
| ND32 | 5 | 1.5 | 1/32 |
| ND64 | 6 | 1.8 | 1/64 |
| ND128 | 7 | 2.1 | 1/128 |
| ND256 | 8 | 2.4 | 1/256 |
| ND400 | 8.6 | 2.6 | 1/400 |
| ND500 | 9 | 2.7 | 1/500 |
| ND1000 | 10 | 3.0 | 1/1000 |
| ND2000 | 11 | 3.3 | 1/2000 |
| ND4000 | 12 | 3.6 | 1/4000 |
| ND8000 | 13 | 3.9 | 1/8000 |
| ND32000 | 15 | 4.5 | 1/32000 |
| ND100000 | 16.5 | 5.0 | 1/100000 |
Frequently Asked Questions
What is an ND filter?
A neutral density filter reduces the amount of light entering the lens without affecting color. It lets you use slower shutter speeds or wider apertures in bright conditions -- for motion blur in waterfalls, smooth water, or shallow depth of field in daylight.
How do I stack ND filters?
Add the stop values together. An ND8 (3 stops) stacked with an ND64 (6 stops) gives 9 stops total. Be aware that stacking can introduce vignetting and reduce image quality.
Why is my long exposure blurry?
Long exposures require a sturdy tripod. Use a remote shutter release or timer to avoid camera shake. Mirror lock-up (on DSLRs) also helps. Wind can cause vibrations even with a tripod.