Quote Originally Posted by Bill Burk View Post
Oh and a reading from spotmeter mode on 18% gray card (0.78 reflective density) and a reading from the incident mode on my meter agreed perfectly this afternoon.
Interesting. In An Interpretation of Current Exposure Meter Technology by Allen Stimson, it says that "the difference [between the exposure meter calibration and the 18% gray card] is due to the angle at which the card is held."

Sorry, small correction, an RD 0.74 equals 18%.