I am in the reassembly process and I need to figure out where to set this filter wheel. It goes in front of the CCD cell and turns with aperature and shutter speed. It turns freely and its little gear meshes with one on the lens plate but no idea on how to "index" it.
I don't know the Rollei but typically these things work the way that the largest opening (or, in this case, that would be the clear portion) is in front of the sensor for the most generous exposure setting (largest aperture, slowest shutter speed, highest iso setting) the camera is capable of and vice versa.