Quote Originally Posted by markbarendt View Post
Interesting. So thinking out loud here... If I get the concept here, flare actually compresses the shadows on the original line of the curve. Even though we are moving into steeper parts of the curve flare is still compressing the tones.

It seems to me then that essentially the construct you speak of is that the normal log exposure vs density curve is replaced by a scene zone placement vs density scale. Even if not perfect is that a reasonable understanding?

If true that almost seems like a better way to visualize what is going to print. It becomes a labeling issue instead of a technical flaw. Seems to me that the log exposure vs density model hides flare's effect.
The x-axis, in my opinion, is always where things get confusing. I like to think of the increments on the x-axis of a H&D curve (regardless of how it is labelled) as relative "camera exposure settings". I think this might be analogous to what you refer to as "placement". In a zero-flare, calibrated system, actual exposure = expected exposure. When there is flare, actual exposure > expected exposure. In the lower values, densities are raised and local contrast is reduced. This is one of the problems with the typical ZS camera test in which we meter a card and stop down 4 stops.