An ND (neutral density) filter is a darkened piece of glass that reduces the light reaching your drone’s sensor without changing color. You need one mainly when shooting video in bright conditions and you want a slower shutter speed for natural motion blur, or when you want longer exposures in photos.
Why Drone Video Often Needs ND
Many drone cameras have a fixed aperture, so exposure is controlled by shutter speed, ISO and, if you add one, an ND filter. In bright sun, keeping ISO at its base value forces a very fast shutter speed. Fast shutters make motion look choppy, as if each frame were a sharp still.
A common guideline is the 180-degree rule: set your shutter speed to roughly double your frame rate, for example about 1/60 for 30 frames per second or about 1/120 for 60 frames per second. This is a baseline, not a law. An ND filter makes that possible in daylight.
Understanding ND Strengths
ND filters are labeled by how much light they cut. You will see numbers such as ND4, ND8, ND16 and ND32, and each step doubles the reduction.
- ND4: cuts about two stops, a light option for modest brightness.
- ND8: cuts about three stops, a common all-round choice for sunny days.
- ND16: cuts about four stops, useful in strong midday sun.
- ND32: cuts about five stops, for very bright scenes such as snow or sand.
How to Use One
- Set the camera to manual exposure, with ISO at its lowest native setting.
- Set your frame rate, then set the shutter speed to roughly twice that rate.
- Check the exposure on screen. If the image is too bright, add a stronger ND filter instead of raising the shutter speed.
- Fine-tune with small changes in aperture, if your drone allows it, or shift the filter strength.
- Check the footage on a larger screen, since small displays hide shutter-related motion issues.
When You Can Skip ND
- Overcast days or low light, where the shutter speed is already slow enough.
- Still photography when you want to freeze motion and keep the shutter fast.
- Slow, gentle flights where choppy motion is less noticeable.
Also consider polarizing (CPL) and ND/PL combination filters, which cut glare on water and glass in addition to reducing light. Make sure any filter you add is compatible with your drone’s gimbal balance, since heavier glass can affect it. Check the drone maker’s page for guidance on compatible filters. We have not used these filters ourselves, so treat all numbers as general guidance.
FAQ
Do I need ND filters for drone photos?
Usually not. Photos are normally shot with fast shutter speeds, so ND filters matter mostly for video or special long-exposure effects such as smooth water.
Which strength should I buy first?
A set that includes ND8 and ND16 covers most daylight situations, and adding ND32 helps in very bright scenes.
The Short Version
ND filters let a drone camera use a slower shutter speed in bright light, giving video a smoother look. Begin with ND8 or ND16, follow the shutter-speed guideline as a baseline, and skip the filter in dim light.
