I now have two inaccurate minolta 2f color meters. I've taken them apart and found one adjustment screw on the main body and six in the head behind the receptor. I've been told via the grapevine that these 6 screws are used to adjust (I tried the one on the body and it seemed to have no effect). Has anyone any experience with calibrating these things? I presume that the six screws are split 3 for each colour group high, mid and low points. I will get a known source light and then adjust for the high and lows using filtration between the source and meter. Anyone see any flaws?