Hi all! I can't find much info on an ND Filter to suit GP3+BE and H3-3D. The search facility isn't the best on this forum. I've decided to side-step from the vision plus to the PV2+Gopro to get better video quality. I've heard many have used neutral density lens for sunny conditions. Firstly, is it required? Anyone got any suggestions? Do they all work the same? Do they all have vignetting? Are they light weight? Any ebay/amazon links? Are there variants such as glass vs other? Thanks in advanced.