> On another note, the bracket that you slide the filters into protrude so > much it can cause vignetting even if the opening in the ring doesn't. On > fully open aperture, that is. The 645-A 45/2.8 is like that, and so is the > FA*24/2.
I have a cut down holder I use on my 6x7 55mm f/4 (77mm filter thread). The grad ND filters work fine, the Cokin polarizer vignettes dramatically when the lens in stopped down. If I want to polarize, I have to use a screw-in Hoya polarizer with this lens. Adding the Cokin cut-down to the end of the Hoya vignettes :-( A bit of masking tape to hold the Cokin filters on the end of the polarizer works though. I use a normal holder on the 6x7 75mm f/4.5 (82mm filter thread). I haven't noticed any vignetting yet. In 35mm, the Cokin holder also works well with the K-24mm f/2.8 yet I've found that Hoya screw-in polarizers (52mm thread) vignette - completely the opposite to the 55mm 6x7! If I was to get a 6x7 45mm f/4 I'm pretty sure I would have to get a Lee filter system for it. In fact I may well standardize on Lee this year if I can persuade the finance department. Chris