From: Lew on 13 Aug 2010 08:27
Isn't there also the claim that, as development & tanning progress in
highlight areas, the emulsion physically compresses (as a result of
the tanning) thereby holding less developer? ie there is even more
moderation of highlight densities than there is via the mechanism of
developer exhaustion alone.
I haven't tested this extensively, but my limited experience leads me
to believe that, on a very sunny day, with the sun overhead, plus
areas of deep shadow, using iso 200 - 400 films, I did obtain easy to
print negatives with plenty of highlight detail.