Interesting comparison of Polarising filters

http://www.lenstip.com/115.4-article-Polarizing_filters_test_Results_and_summary.html

I have Marumi and Hoya Pro 1 – I find the Hoya’s very difficult to clean without scratching them, so I wouldn’t recommend them. I am after a slim 105mm for my Lee Filter system, as the Lee Polariser is too deep and causes vignetting with my Zeiss 21mm and even the Canon 24 -105mm

Unfortunately B+W don’t make a slim mount 105mm polariser but Heliopan do.