I'm looking into getting some ND filters for the AF-S VR Zoom-Nikkor 200-400mm F/4.0G IF-ED lens. This lens uses a drop-in filter holder at the back. I'm unsure if something like this will work or not: http://www.adorama.com/BW52ND64XW.html Probably looking at 8x and 64x filters - I want to reduce the amount of light getting into the lens in daylight to drop the shutter speeds lower. Has anyone done this already and could confirm that it will work? I may visit a local camera store this afternoon - but it's so much cheaper to buy from Adorama!