Darwin, I just recently acquired my G11 and started using my Singh Ray filters with it. The LB warming polarizer + any grad produces a very strong magenta color cast. Do you find any similar issues? I open the raw files in Lightroom and with or without the filters they look a little washed out. Perhaps I should use the Canon software? I am a Nikon guy (shudder at the thought, I know) and have not had any such issues unless I mix Singh Ray & other brands.