gen-briefly-explain-the-inverse-square-law-for-lighting-and-one-e6d9

Briefly explain the inverse-square law for lighting and one common misconception about it.

## Inverse-Square Law for Lighting The inverse-square law states that light intensity decreases proportionally to the **square of the distance** from the source. If you double the distance from a light, the intensity becomes 1/4 as bright (not half). Triple the distance, and it becomes 1/9 as bright. Mathematically: Intensity ∝ 1/d² ## Common Misconception **"This applies to all lighting situations"** Many people assume the inverse-square law works universally, but it only applies to **point light sources** in free space. It breaks down for: - **Large/diffuse sources** (like softboxes or overcast skies) at close distances - **Focused beams** (spotlights or lasers) that don't spread significantly - **Very close distances** where the light source size matters relative to the subject In practical photography/cinematography, the law works well for small lights at moderate distances, but a large softbox positioned close to a subject will show much more gradual falloff than the inverse-square law predicts.