Rembrandt lighting
Rembrandt-licht · Light
A classic lighting technique where a small triangle of light is visible on the shadow side of the face.
One light source, 45° to the side and 45° above the subject. The small triangle of light under the shadow-side eye instantly adds depth and character. Classic for black-and-white portrait. You can do this with window light too: seat your subject at an angle to the window.
Tools that help with this: