Originally Posted by Bill Burk
Except it's not about averaging meters. Exposure is about the placement of illuminance on the film curve. I'm suggesting that's where the middle gray is determined. And what makes the camera image different from the original scene? You guessed it - flare. Flare changes how the original scene appears in the camera.
For the average 2.20 log luminance scene, the highlight falls 0.92 log-H above the metered camera exposure. The shadow falls 1.28 below. This imbalance doesn't make sense except when you factor in flare. Add 1 1/3 stops of flare to the shadow and it now falls 0.94 below the metered exposure. Now there's 0.92 log-H above and 0.94 log-H below. As the highlight falls at 100% Reflectance, RD 0.00 and the metered exposure falls 0.92 below, RD 0.92, or 12% Reflectance.
Last edited by Stephen Benskin; 12-28-2011 at 11:59 PM. Click to view previous post history.