Neutral Density Filtration for Videography Follow
Video uses neutral density filters as much, if not more than stills!
Typically, a video camera has a preferred ISO, and it is often in the ISO 400 to ISO 1200 range. Shutter speeds are best set to 2x the frame rate. If you are shooting your video at 30 frames per second, your shutter speed should not be higher than 1/60th of a second, otherwise movement is going to start to look weird.
Consumer video cameras typically have very small maximum apertures on very small sensors to try to keep everything in focus.
The popularity of DSLR and mirrorless cameras is to a large extent driven by their ability to be used with higher quality and optically faster (larger maximum aperture) lenses, specifically to allow for more depth of field control. If shooting in bright light the lens may be stopped down to a small aperture, so the ability to get shallow depth of field is negated. Adding an appropriate neutral density filter will reduce the incoming light, allowing for wider apertures for more creative control of depth of field.