But, interestingly Fred Picker did believe almost every picture should have a bit of maximum black and maximum white (or at least Zviii).

In the last years of his newsletter he was advocating determining exposure by picking the high value and placing it on Zviii. (He also advocated making a second exposure with the high value at Zvi1/2 so that one had choices when printing. I believe this was after he began selling multi-contrast paper and heads.) Anyway, when I started putting the high value on Zviii and letting the shadows fall where they may, my pictures really went to hell.
juan