I've been thinking recently how important value is to a painting, or to any design. Looking at a painting earlier today by Dean Cornwell, I found myself categorizing the light shapes and shadow shapes; when simplified to their basic forms, these forms balance out. They would, of course; it's Dean Cornwell. His compositions are incredible. Here's a few examples of fantastic use of value (not all Dean):
|Thomas Eakins' "The Agnew Clinic|
In the first example, the focal point is obviously the sitting man; in that, his face. Cornwell could have easily let the fact that our eyes are attracted to faces in compositions and that fact that this man is in the center of the page aid him to his goal, and be done with it. However, to really solidify this composition and to force us to never unstick our eyes from this image, he wedged his focal point directly between the brightest note and the darkest note. Now, the intensely orange leaves may not be the highest value on the page; however, their intensity and singularity of color in this particular painting give them the ranking of brightest element in the arrangement. Also consider the other ways in which he pumped up his composition: 3 of the four table edges around the sitting man point directly to him. The left edge of the cradle to the right is parallel to the edge of (his) left arm. The bottom of that cradle is the bottom of a circle, that swings up and into his right leg, up into his mass. the right edge of the table at bottom-left also leads our eye into his left arm, up and around back into his shape. And probably most importantly, the 2 edges of the bright orange leaves' contour also lead directly to the focal point, a large upside down triangle that is intersected by the triangle of the man.
In the second example, the use of value isn't nearly as pronounced or glaring as in Cornwell's piece, but Lovell's use of it is very important for the composition. Take note first of the goal of the composition; the focal point is the tall man at left, as our eye goes straight to him. This is immediate because of his height, broadness of chest, and placement next to the brightest note in the painting. That contrast causes us to go to him straight-off. However, to keep him as our focal point, Lovell needed to keep all other elements in order so that our eye would not wander off. The man, a large, generally dark shape, is bordered on both sides by the 2 brightest shapes, the woman and the environment outside; the woman looks up at him, concerned; her whole thrust of action is towards him: her gaze, the lines of her arm, her posture, etc. Off this side of the page we cannot go. To the right, the dark shape in the curtains to the right of the man's head leads straight away; however, it is intercepted by the almost equally dark shape of the palm trees, multiple lines heading down. This leads down to another man, hunched over a table. For compositional purposes, this man and the table he is leaning over are the same visual object: they have the same general value and flow directly into one another through his arms. This combined shape purposefully borders the brightness of the day outside and leads straight to the focal point's arm, which, in turn, leads us again to his face. We have no chance to leave the page off the bottom, sides, or top.
In the final example, value is combined with character and personality to achieve balance in the composition. Eakins used quite a simple compositional concept here. Andrew Loomis speaks of the "fulcrum-lever" principle as applied to composition in his staple book, Creative Illustration (download all 6 of his incredible books as .pdf's here: http://alexhays.com/loomis/). Basically, visual weight needs to be placed strategically on both sides of a composition in order to balance it. Now, different elements can have different visual weights for different reasons, and they all must be considered. Obviously a feather is going to have less visual weight than an anvil. However, there are other things which draw our eye: gesture, character, personality in a figure. In The Agnew Clinic, there is only one person with individuality: the proctor at left. We know of his importance immediately; he stands out, speaks to the crowd, directs his charges (students? doctors?) and breaks out of the circle the others are directly in the middle of. In addition, he is also weighed down by the fact that he is a dignified silhouette, an interesting light shape in a sea of dark bodies. Notice also how his is the only face not obfuscated in some way; the faces in the crowd are dark and obscured. The faces of the working doctors are down-turned, adorned with glasses, etc. The only other character whose face is fully hone and lit is the nurse; however, she is so unimportant to the scene that it doesn't matter.
So, the weight is like this:
small importance -----------------large unimportance
Very very basic way of putting it, but generally correct.
Next time you look at a piece that really strikes you, look into it, analyze it. It struck you for a reason; it is by no means an arbitrary happening.