Hi, I'm looking to buy a high-end 67mm circular polarizer, preferably slim. I'm currently using a Hoya (non-slim), but I've noticed that with my Nikon 18-70/D50, most of my pictures come out with a very noticeable yellow color cast. I'm assuming this is the filter's fault. Also, I'm hoping the "slim" filter will cut down on vignetting at 18mm. Let me know what you've got and how much you want for it (via reply or PM.) Thanks!