as above, this is why there are different filters,
the best way I have found to get the correct filter is if in your camera settings if you flick on to manual the EV will give you a figure + or -, if it is say + 2 then you require a ND2 filter, if is was 4 or 6 . . you get the idea, just slapping a 16 on and saying it will do isnt going to get you the best results,
once you have powered off the drone and fit the correct filter do the same test, once the EV is pretty close to 0 just stick it back in Auto and have fun, it just stops the camera having to do so much more work then just record the image.