Drone Tips and Tricks
In Short YES!
ND filters or Neutral Density Filters reduce the light intensity without changing the color.
There are different brands all with different levels of filter from 2 up to 1024. The values double each step and it will become clear later in the article. For DJI drones, DJI sells ND4 ND8 and ND16, for the Phantoms, Inspire, and Osmo, other brands include ND2, ND 32 and ND64.
Without getting too technical, exposure levels on the camera are called stops. to decrease the exposure to the sun that the sensor sees (or lower the shutter speed) we have to limit the amount of light into the lens. Think of the ND filters like sunglasses for the camera.
At ND2 the amount of light let into the camera is cut in half. So 50% is allowed in.
At ND4 the amount of light let into the camera is cut in half again. So 25% is allowed in.
At ND8 the amount of light let into the camera is cut in half again. So 12% is allowed in.
At ND16 the amount of light let into the camera is cut in half again. So 6% is allowed in.
And so on. You can see why DJI does not bother with anything above ND16. But darker filters would be more useful in shooting directly into the sun or extreme light environments. Or possibly doing a long exposure during daylight hours.
By adding the ND filter, less light is able to get into the camera and the shutter speed can be slowed down. This is most relevant for video. When the shutter speed is too high the video becomes too sharp and jittery, also many people experience what is called jello in the video. In bright daylight you may get shutter speeds of 1/800, 1/1000, or even higher. This is much to high for good video. If we slow the shutter manually the image will get over exposed and washed out. If we add ND filters first the shutter will have to stay open longer in order to let the proper amount of light into the lens.
The rule of thumb for video is you want the shutter speed number to be as close to double (2x) the frames per second of the video. If you are shooting in 30fps then shutter speed of 1/60 is ideal. At 24fps 1/50 is best. At 60 fps needs, 1/120 shutter speed, and so on.
Keeping shutter speed and frames per second in check there is the right amount of motion blur in the video creating a smooth looking experience for the human eye. If the images are too sharp there isn't enough blur to make the video flow.
Using the ND filters for photos allow you to keep the shutter open for longer while still achieving the proper exposure levels. This kind of photography allows you to blur the subject to create fluidity in the picture.
Practice, practice, practice. Trial and error. Keep at it until you figure out which filter to use in what situation, welcome to being a photographer.