A secret to good composition is to group and simplify the tones. But the tonal organization must serve the story.
Let's look at an example, along with my pencil sketch.
|Nils Forsberg (1842-1934) La Fin d’un héros (Death of a Hero) 1888|
Oil, 300 x 450 cm, Stockholm, Nationalmuseum
At the moment of his death, a war hero is slumped on his improvised bedding. The setting is a church. A priest gives him last rites. His wife or mother grieves at the foot of the bed. His fellow soldiers pay last respects. On the left are other wounded patients laid out on other beds.
The dying hero is the crux of the design. He is a light shape surrounded by the light-toned bedding. Those light patches are shape-welded to the illuminated vertical column behind his bed.
I don't know if it was intentional, but that column ascends like an elevator to heaven. The only other light-toned figures are the altar boy with the candle and the attending priest.
The rest of the mortals are mostly dark. The ailing figures on beds on the left are enveloped in darkness. Wherever possible, dark tones are grouped into large shapes to simplify the design.
Perhaps I'm reading into it a bit, but the light seems to be associated with spiritual life or afterlife or redemption, and the darkness seems to be associated with mortality and suffering. The point is that tonal organization isn't just a design issue, it's also a story issue.
Previously: Shape Welding