Years ago I bought a blue-yellow polarizing filter, after reading an article about it in Outdoor Photographer magazine. I shot some interesting pictures with it, then set it aside, for, oh, a decade. I had completely forgotten about it until a few months ago- after buying a new SLR, I rummaged through my old camera bag and found all kinds of cool things. I decided to give it a try on a hike today to Lory State Park. This was my favorite shot of the bunch. The filter really gave the green lichens on the rock an unworldly shine.