Formula Used
The calculator converts all exposure changes into stops. It then multiplies the base shutter by the total light factor.
Filter factor = 2filter stops
Aperture stops = 2 × log₂(target f-number ÷ base f-number)
ISO stops = log₂(base ISO ÷ target ISO)
Total stops = filter stops + aperture stops + ISO stops + exposure compensation
New shutter = base shutter × 2total stops
How to Use This Calculator
- Meter the scene without the dark filter attached.
- Enter the shutter speed shown by your camera.
- Keep filter strength at 10 stops for a 10 stop filter.
- Enter aperture and ISO changes if you will change them.
- Add exposure compensation when you want a brighter or darker result.
- Choose a rounding option for easier field timing.
- Press the calculate button and read the result above the form.
- Download CSV or PDF when you need a saved record.
Example Data Table
| Base Shutter | Filter Stops | Base Aperture | Target Aperture | Base ISO | Target ISO | New Shutter |
|---|---|---|---|---|---|---|
| 1/60 second | 10 | f/8 | f/8 | 100 | 100 | About 17 seconds |
| 1/15 second | 10 | f/8 | f/11 | 100 | 100 | About 2 minutes 16 seconds |
| 1/4 second | 10 | f/11 | f/11 | 200 | 100 | About 8 minutes 32 seconds |
10 Stop ND Filter Guide
What the Filter Does
A 10 stop neutral density filter blocks a large amount of light. It lets the camera keep the shutter open much longer. That creates smooth water, soft clouds, empty streets, and calm motion effects. The filter does not change color on purpose. It only reduces light.
Why the Exposure Changes
A ten stop filter multiplies shutter time by 2 to the power of 10. That equals 1024 times more exposure time. A base speed of 1/60 second becomes about 17 seconds. A base speed of 1/4 second becomes about 4 minutes and 16 seconds. This calculator performs that conversion. It also includes aperture, ISO, and compensation changes.
Planning the Shot
The tool is useful before sunrise, during bright noon light, and near sunset. It helps you plan a safe exposure without guessing. You can enter the metered shutter without the filter. Then enter the filter strength. Keep it at 10 stops for a normal 10 stop filter. Change it when stacking filters or using a variable filter.
Advanced Adjustments
Aperture and ISO also change exposure time. A smaller aperture needs more time. A lower ISO also needs more time. The calculator handles those adjustments by converting each change into stops. It then combines all stop changes into one factor.
Field Technique
Long exposures need careful timing. Use a tripod. Cover the viewfinder if your camera leaks light. Turn off stabilization when the camera is locked down. Focus before fitting the dark filter. After the filter is fitted, autofocus may struggle.
Long Exposure Checks
Very long exposures can create noise or color shifts. Some cameras apply long exposure noise reduction. That can double waiting time. Film users should check reciprocity failure data. Digital users should watch battery level and sensor heat.
Saving Results
This calculator gives exact seconds, rounded timer values, bracket times, and a simple note. The CSV option saves numbers for later comparison. The PDF option creates a quick field sheet. Use the result as a strong starting point. Then review the histogram and adjust with experience.
Practical Tip
Always test your own filter first. Real filters may be slightly stronger or weaker. Label your filter pouch with measured values. Keep a remote release ready. Use the bracket results when light is changing. They help protect highlights and preserve shadow detail during creative shooting and safer timing.
FAQs
What is a 10 stop ND filter?
It is a dark neutral density filter that reduces light by 10 exposure stops. It lets you use much longer shutter speeds in bright conditions.
Why does the calculator multiply by 1024?
Each stop doubles exposure time. Ten stops equal 2 raised to 10, which is 1024. That is the basic filter factor.
Can I enter 1/125 as a shutter speed?
Yes. Enter 1/125 in the shutter box and choose seconds. The calculator reads common fractional shutter speeds.
Should I change aperture values?
Change them only when your metered aperture differs from your shooting aperture. The tool will adjust exposure time for that change.
How does ISO affect the result?
Lower ISO needs more exposure time. Higher ISO needs less exposure time. The calculator converts ISO changes into stops.
What does exposure compensation do?
Positive compensation increases exposure time. Negative compensation reduces exposure time. Use it when you want a brighter or darker final image.
Why are bracket times included?
Bracket times help when light changes or the meter is uncertain. They give faster and slower exposure options around the main result.
Do I still need to check the histogram?
Yes. The result is a strong starting point. Always review highlights, shadows, and motion after taking the exposure.