Rim light and backlighting; top lighting; underlighting

Use rim, back, top, and underlighting to place light and shadow while preserving solid forms and material cues.

What it is

These setups place light from behind, above, or below the subject. You track which planes catch light, which fall into shadow, and how contrast affects the subject's three-dimensional read.

Rim and backlighting leave most of the subject in shadow while a strip or halo follows contours facing the source. You control the rim's width, sharpness, and spill into translucent areas such as ears, hair, or smoke. Cloth can have softer edges, while metal can have sharper ones.

Top lighting favors upward-facing planes, including shoulders, cheekbones, nose bridges, and the tops of props or scenery. Downward-facing planes fall into shadow, so you control facial falloff, eye-socket depth, and bounce light. Underlighting reverses this pattern, illuminating areas beneath the chin, nose, and brows while the top planes stay darker.

Why it matters

These setups test whether you can shift light direction while keeping planes connected and forms readable. Weak control can make rim light look like a separate outline, bury facial features under top light, or place underlighting highlights without convincing form.

You can check it when

• ✓Light a sphere, cube, or cylinder from behind, above, and below. The lit and shadowed planes shift logically in each setup.
• ✓Paint a head with rim light only. The head retains visible volume through its shadow shapes and edge light.
• ✓Top-light a face while keeping the eyes, mouth, and nose readable within the changing shadow pattern.
• ✓Underlight a face or object so the same forms remain recognizable, with highlights on lower-facing planes and darker top planes.

Related skills

• The shadow family (core, form, cast, contact/occlusion)
• The light family (halftones, highlights, speculars, reflected light, terminator)
• The edge spectrum (hard, soft, lost, found)
• Source size → hard vs. soft light
• Reflectivity at glancing angles (Fresnel effect)
• Head construction (skull, head planes, Loomis-style or equivalent)
• Multiple light sources