I recently got a 550 Polaroid back and shot my first sheet of FP100C45. I think this could really come in handy for verifying exposure and composition for important shots. Using my usual metering technique (guess exposure), my test-Polaroid turned out somewhat overexposed. I suppose this is unsurprising since I generally expose negative film with just a bit of a "safety factor" but I was wondering how much latitude this stuff has. If it's anything like color transparency film, then I should get a good negative exposure if I get any sort of picture at all on the polaroid, and the slight over exposure I saw today is nothing to worry about. But, I'm not sure.