ND filter
Also known as: neutral density filter, ND filters
A neutral density filter is tinted glass that cuts light evenly without changing color, so the camera can use slower shutter speeds in bright light.
Updated
What it means
An ND filter works like sunglasses for the lens. It reduces the light reaching the sensor without shifting colors, so the camera can use a slower shutter speed than the scene would otherwise allow. Strength is written as ND4, ND8, ND16, ND32, ND64 and so on, and each doubling of the number cuts one more stop of light.
For action cameras and drones this matters more than for most cameras, because their aperture is usually fixed. Without ND, the only way to handle bright sun is a very fast shutter, which strips out natural motion blur and makes movement look choppy.
How it works in practice
DJI and third-party brands sell ND sets for most Mini, Air and Mavic drones, and clip-on or magnetic sets exist for GoPro and DJI Osmo Action cameras. A typical drone routine: set ISO to its lowest value, set the shutter to roughly double the frame rate, then swap filters until the exposure meter sits where you want it.
As a rough guide, overcast days need ND4 or ND8, bright sun calls for ND32 to ND64, and snow, sand or water in full sun can need even stronger glass. This is how drone pilots manage to follow the 180-degree shutter rule at midday.
What to watch out for
Fitting an ND and leaving exposure on auto mostly defeats the purpose: the camera picks its own shutter, often still far from the speed you wanted, or shifts ISO instead. Lock the shutter manually first, then choose the filter that makes the exposure work.
Cheap filters can add a color cast, often magenta or green, soften the image or flare in backlight. On drones, a heavy or badly seated filter can strain the Gimbal and trigger errors, and on FPV quads crashes crack filters easily, so carry spares. Take strong ND off when the light drops - a forgotten ND64 at sunset forces high ISO and noisy footage.
How RawClip handles it
Filters change the footage itself, so they belong on the camera while shooting. RawClip accepts drone and action-camera clips up to 5.3K, in H.264 or H.265, from mixed brands in one order, and turns them into one finished highlight delivered in 4K and 1080p.