I have used the Cokin P system with their polariser, square and ND grads on Mamiya 7II with no problems at all.

By Keith Davison on Tuesday, January 13, 2004 - 05:11 am:

can anyone tell me whether cokin filters P series including lens hood will interfere with the metering on 7ii & 65mm lens ie does the sensor pick up the back of the filter housing
and I understand that the metering for 65mm lens is spot not cwa is this correct?