Sunlight & Shadows

Parallel versus central projection

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Lamps cast shadows by central projection; the Sun by parallel projection.
• Parallel projection keeps parallel lines parallel and ratios along lines.
• Lamp shadows grow as you move away from the lamp.

Steps

1. Two kinds of shadow
2. Set the Sun
3. What survives
4. A shadow from the Sun
5. Converging shadows
6. Lamp shadow