Tuesday, January 25, 2011

Center Light

The center light is the main modeling factor out in the light. It takes the flatness out of the  planes in the light area. It makes form out in the light.

It is found only on round forms. 
It is a half value lighter than the average light value.
There are no hard edges on the center light. 
The center light is found and used most effectively on the upright plane. 
It widens and narrows with the form.
Create the center light on big forms first, then break in into smaller forms.

If the average in the light is 7th value, you can  lay in the center light a full value lighter and brush it down on all sides to soften and darken it to 7 1/2. Remember the highlight will be a full value lighter than the average, the center light has to be in between. There is no hue change, hold the local. There is no significant chroma change. It might be slightly weaker, but making it too neutral will weaken the edge plane (edge planes is a subject for an upcoming blog segment).

Once the curved form becomes a corner, the modeling factor
becomes a highlight, not a center light. 

Shape of the form dictates shape of the center light.

As the thumb turns towards body,
the forearm twists and the center light follows. 

In the illustration below, Reilly indicates a step-by-step procedure for painting the center light. After laying-in the light, shadow and halftone, add the center light, softening the edges as needed. Then add the cast shadow from the jaw. 

Try this exercise at home. 

© John Ennis 2011

Next Topic: Highlight