I am looking to pick up a 55mm polarizer for my Contax lenses. I know the cicular ones are needed for AF cameras and in general linear ones are good for MF cameras. My question is this: All the ads I have been reading online regarding these filters say that "some MF cameras require circular polarizers". Can I get by with a linear for my 167mt? I have no other need for 55mm filters than for this system so if I can save a few bucks by not getting the circular I would like to do so. Thanks!