Reflection in Universal Light, Lighting the Muscles, and Painting White
Derivative light h reflects onto d; moving lights reveal the figure
This page of the Treatise on Painting opens by defining how reflection arises in bodies lit by universal light, illustrated by a small semicircular diagram lettered e, f, d and h that shows the derivative light h reflecting onto the less-lit location d. A second chapter argues that particular, small, moving lights, not universal ones, best reveal the figure of the muscles, since a fixed light would leave much of a muscular body dark and unknown. A third chapter begins the treatment of how to depict white bodies, which have no color of their own and take on the color of surrounding objects, opening with the example of a woman dressed in white in a landscape.
On this page
How reflection is generated in universal lights
Reflection arises when a part of an illuminated body throws its greater light onto a place that sees a lesser part of the same light. Seeing the sky e f at location d, while a greater part of that sky is seen at h, the derivative light h reflects onto d.
Diagram of derivative light reflecting
A small semicircular pen diagram at the top of the page shows rays within the hemisphere of the sky, lettered e, f, d and h, illustrating how the light h is reflected toward the location d.
Which lights best reveal the muscles
For giving a true notion of the figure of the muscles the universal lights are not good, but particular ones are perfect, the more so the smaller they are. The light should be moved in several directions, for a fixed light would illuminate only a small part of the muscular body and leave the rest dark and unknown.
How white bodies should be depicted
White has no color of itself but is tinged and transmuted in part into the color of the object before it. A woman dressed in white in a landscape, in the part struck by the sun, will be so bright that, like the sun, she in part troubles the sight.