If you use a matte box that clamps onto the lens, beware that it will radiate a lot of noise from an Arriflex 35BL camera. It will cause the camera to be three times noisier. A clamp-on matte box is no problem for Arri 535 or Moviecam cameras. Clairmont Camera has a handheld matte box for the 35BL that attaches to the BL square hole at the carry handle and this will not radiate noise. Clairmont Camera can provide ways to use polarizing filters on their hand-held matte boxes and the Arri LMB-5 matte box.