Mind-Blowing Realistic Shading Tricks

Summary by Krater

Artist and teacher Dorian Iten explains Lambert's emission law and how tonal values change on a form as it turns away from light, demonstrating why the light-to-shadow transition is more gradual than a linear value scale suggests.

From the video

Answers: How does light interact with form in drawing, and why do values change non-linearly near the terminator?

• Shading light and form
• Lambert's emission law
• Linear value scale
• Lambert value scale
• Common shading mistakes

What it concludes

• At an 80 degree inclination, brightness is 45 percent rather than a linear expectation of 10 to 15 percent.
• At a 10 degree inclination from straight up, brightness is 99 percent.
• In shading, tones change very slowly near the lightest lights and begin to darken more dramatically as they approach the terminator.
• A linear scale gets way too dark way too early compared to Lambert's cosine-based scale.
• To avoid dirty lights, light halftones must not be made too dark too soon and value changes in light values must be kept very subtle.