Ian Brunton , Apr 17, 2003; 07:52 a.m.
As no one has replied yet, I'd suggest that few people have heard of them. But there are several such brands around, including Phoenix, and a lot are made by the Japanese optical glass giant THK (Tokina-Hoya-Kenko, I think). Since many people seem to obsess about differences between Nikon and B+W, I don't think many people would recommend them.
Still, if you're after a cheap filter that you won't use that often (like a fluorescent to daylight), it might be worth buying, but you could probably get better filters cheap on eBay. If it's a filter you'd use a lot (polariser, UV, black-and-white tonal correction...), it's probably not a good idea to put an iffy filter in front of a nice lens.