ND Filter Calculator
Use this calculator to work out what your new exposure will be, taking into account reciprocity, or which filter is needed to get you to the exposure you want.
ND filter calculator
Meter without the filter, add the ND filters you're stacking, and get your new exposure time, corrected for your film's reciprocity.
Type a fraction (1/125) or seconds (2). Choose "No reciprocity correction" for digital.
Add filters
New exposure
–
Filter strength–
Light factor–
Optical density–
0:00
A tone plays when the exposure ends. Keep this page open during the exposure.
Which filter do I need?
Enter the exposure time you want, and we'll suggest filters using your metered speed above.