Beware. This link is 4 years old. Much has changed since then.
You need to refer here I believe:
https://www.caa.co.uk/Consumers/Unmanned-aircraft/Our-role/Airspace-restrictions-for-unmanned-aircraft-and-drones/
As I said earlier - ND filters DO make a difference to the final image appearance. In two ways. 1. Enabling a long shutter shutter speed on bright light to create the effects of movement (like water and clouds). 2 Enabling a wide aperture on bright days in particular (weddings?) to enable...
ND filters can improve images by allowing improved creative effects. All they do is control the amount of light entering the lens thus allowing shutter speeds to be reduced (enabling movement effects) or opening the lens aperture as wide as possible (for depth of field effects).
Both of these...
I use my ND filters to enable a greater cinematic effect on video. They enable me to slow the shutter speed to twice the frame rate. So for a frame rate of 30fps I use 1/60th second shutter speed (with an appropriate ND filter). Google frame rate v shutter speed.