Photography · Free tool
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.
