Ya neutral density
Nvr try b4 but read they can do amazing stuff
But just curious is it needed to obtain shallow dof or blur image?
Normally for landscape lens uses only or cos lens have diff diameter lol
getting shallow dof is only one of the small usage during strong light such as flash photography.
thats lens dependent as well.
ND at different numbers mean how much light it blocks off.
usually to use slow shutter, we stop down aperture, but after certain level, you'll get lens diffraction which image quality is going to degrade as u stop down even more.
so in order to use slow shutterspeed in bright daylight for capturing stuff like moving water, cloud and the like, people use ND or even GND