David, yes, negative, positive aberrations are used for balance each other. But it opens a new questions , is it explains everything. I have a Ektar ,my mother and I agree , when you look from the back of the lens , skin details, shadows, lines, 3d curves are faraway being increased and visible. Faraway, different than the eye sees. Why ? Are these high aberrations and compensartions used for something also ?

Umut