FREE · CALCULATORS & CONVERTERS
ND Filter Calculator.
Convert an ND factor, stop count or ND number into a new shutter time and optical density.
The new time is the base shutter times the factor. One stop is a factor of 2. Optical density is log10 of the factor. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional.
- Factor
- 1,000
- Stops
- 9.965784
- Optical density
- 3
- New shutter
- 10 s
One stop doubles the exposure. The new shutter time is the base time times the ND factor. Optical density is the base-10 logarithm of the factor.
How to use ND Filter Calculator
Enter the filter as a factor, a stop count or an ND number such as 1000, plus the base shutter time in seconds.
How it works
Convert an ND factor, stop count or ND number into a new shutter time and optical density. The new time is the base shutter times the factor. One stop is a factor of 2. Optical density is log10 of the factor. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional.
Example
ND 1000 on a 1/100 second shutter.
Questions about ND Filter Calculator
Is ND Filter Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
The new time is the base shutter times the factor. One stop is a factor of 2. Optical density is log10 of the factor. Local arithmetic only. This is a quantity or geometry estimate, not a code check and not a substitute for a licensed professional. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.