I use a filter set from Polar Pro and they work just fine. They just attach onto the front of the lens without any issue. They come in a set of 3 - ND4, ND8, PL. I find that I use the ND8 in most sunny situations, ND4 for cloudy/overcast and late afternoons. I haven't tested the PL yet. It doesn't add much extra weight to the gimbal.