That's the part which is the construct. It doesn't really exist. What actually happens is flare adds to the shadow exposure. This moves it to the left. In the example for a 2.5 flare factor, the shadow exposure shifts from relative log-H 0 to point A. A 5 filter factor shifts the shadow exposure to B and a filter factor of 10 shifts it to point C. The shadow exposure no longer reaches down to relative log-H 0.
Originally Posted by Bill Burk
Henry Flare Curve .jpg