Free Video ND Filter Calculator
Video forces a fixed shutter speed (the 180° rule) — so in daylight you can't stop down or speed up the shutter to fix exposure. The only lever left is a neutral density filter. This calculator tells you exactly how many stops and which filter.
Your shoot
Result
Why video needs ND filters
Stills photographers "fix" bright scenes with shutter speed and aperture. Videographers can't:
- Shutter is locked by the 180° rule (1/48 s at 24 fps) — the motion blur is the look.
- Aperture is limited — stop past f/8–f/11 and diffraction softens the image; plus you often want f/2.8 for shallow depth of field.
- ISO bottom is limited — most cameras go to ISO 100, and going "below base" is impossible.
With a fixed 1/48 s shutter at base ISO in sunlight, the only thing left between you and overexposure is glass in front of the lens. A 6–10 stop variable ND covers nearly every daylight situation.
Related tools & guides
Shutter Angle Calculator
The 180° rule, computed for any frame rate.
Open →ND Filter Calculator
Stills long-exposure math — same stops, different use case.
Open →ND Filter Long Exposure Chart
The full stops reference table.
Read →Video ND FAQ
What ND strength should a videographer buy first?
A variable ND 2–5 or 6–9 stops covers daylight at typical apertures. Pair it with a fixed ND64 (6 stops) for the rare case you need repeatable settings. Avoid cheap variables — they cause X-pattern color cast at the dark end.
Does the calculator work for log / flat profiles?
Mostly — log profiles change the exposure curve but not the light math. You may find you need ⅓–⅔ stop more ND when exposing-to-the-right for log; check the histogram and add a third-stop if the highlights clip.
What if my base exposure is between two filters?
Split the difference: open the aperture ⅓–½ stop, drop ISO one step if you're above base, or use a variable ND. The calculator shows the closest filter and the gap — a gap under ⅓ stop is usually fine.