I haven't seen anyone mention Heliopan filters. Here's the blurb from the B&H site: "Heliopan filters are made exclusively from raw glass supplied by Schott (Zeiss), the world's leading optical glass manufacturer. This guarantees that Heliopan filters are the highest quality possible. The glass is "dyed in the mass" and ground and polished to precise optical plane parallelism, and they are double hard coated on both sides. All Heliopan filters are mounted in black anodized brass rings to ensure optimal performance and ease of mounting and unmounting. This insures that they meet the high standards which are the basis for the unsurpassed reputation of the German optical industry!" I've been using Heliopan polarizers to good effect and I'm curious if anyone else has any experience with them.