I just got a 500C with a 80MM and split focussing screen. Went out and shot some PlusX today and tanked two rolls tonight. And every dang one of them is out of focus. I shot with the lens stopped down to about f8 (brackets) and even those were off focus. Focus on 90% of the shots was at infinity (landscapes) but still out of focus on paper. Checked my enlarger lens and condenser and did a shot from my Mamyia 645 and it was razor sharp. So not the enlarger. What gives? Could it be the A12 back pressure plate? I have another back but it has a roll of Portra in it so can't test until tomorrow. I bought the unit from a local guy not Ebay and the camera and lens look perfect. Am I missing something?