Hi, I get:
1. Planes appear lighter or darker depending on the angle they are compared to the light source
2. Planes can appear lighter or darker depending on position of the observer. ie. because not all light is reflected in random directions, smooth objects can reflect more light at a certain angle.
I want to know if a plane appears darker because it is oblique to the observer. This is suggested here: http://conceptart.org/forums/showthread.php?t=14739
on page 2
If so, why?
Does that explain why the horizon is darker (ie. planes further away will get closer and closer to being oblique) or is it just the waves bunched up. see here: