The Doppler effect explains changes in the length of light waves or sound waves as they move toward you or away from you.

VOA: special.2009.04.29

His specialty was representing the effect of light on an environment with color and loose brushstrokes.

VOA: special.2010.08.04

"Chiaroscuro" is a method using light and shade as a painterly effect.

VOA: special.2010.09.15