Chairoscuro

Light and dark values “model” form, giving the 3 dimensional character to what would otherwise be a flat shape.

Light and dark shapes act independently Light and dark shapes act independently. A group of individual objects in a similar lighting situation bind together to form new “franken-shapes.” You can unify and balance a composition by focusing on the placement of the light and dark franken-shapes.

Lost and Found Edges – boundaries between objects sometimes disappear in some places and reappear in others

Light and shadow are successful at grouping objects because of the phenomenon of lost and found edges.

Chairoscuro, the effect of light and dark, isn’t limited to high contrast situations. Look at this image. There are a wide range of values. There are some areas of high contrast but overall, there is a lot of middle range contrast. However, notice the way the big dark shapes frame the light shapes.

What if you started off a drawing by thinking about the shapes of light and shadow, independent of the individual forms? It would mean letting go the safety of drawing the objects first and then shading. What might be hard about that? What might the benefits be?