The Mamiya polarizing filter is compatible with all Mamiya 7 Series lenses, (both 58mm and 67mm filter diameters) and mounts bayonet style on the front of the lens barrel in the same manner as the lens hoods supplied with each lens.
It is designed for adjustment and verification of light polarization effects and makes AE (Automatic Exposure) or Manual exposure modes simple without need of exposure compensation
The filter shifts vertically from the shooting position in front of the lens without changing its polarization rotation to cover the small square window which contains the metering cell above the lens mount
The polarization effect is observed by looking directly through the filter over the top of the camera (not through the camera's rangefinder eyepiece)
After determining the polarization effect and metering, the filter is returned to the down position in front of the lens