Today I read about light logic, which results in four aspects of light and shadow:

1. Highlight (brightest light)
2. Cast shadow (darkest shadow cast by a subject blocking light)
3. Reflected light (dim light, bounced back by other surfaces)
4. Crest shadow (shadow that lies on the crest of a rounded form, between highlight and reflected light)

To practice seeing these types of light, I did a copy of Gustavo Courbet’s self-portrait.

Here is a comparison of the original (top) and my copy (bottom):