In this note, we are going to know about the **Inverse Square Law of Illumination**. Welcome to **Poly Notes Hub,** a leading destination of **engineering notes** for diploma and degree engineering students.

Author Name: **Arun Paul**.

## Inverse Square Law of Illumination

According to the **Inverse Square Law of illumination**, the intensity of light or **illumination** from a point source reduces as the square of the distance from the source increases. In other words, increasing the distance from a light source reduces the illumination to one-fourth of its original intensity.

**I∝(1/d ^{2})**

**where:**

- I =
**intensity**of illumination. - d = distance from the light source.

## Practical Application of Inverse Square Law

- In architectural and stage lighting, this law aids in the placing of lights to reach desired illumination levels.
- Photographers utilize this equation to adjust light sources for
**optimal exposure**and effects. - Calculates the required light source distances and intensities to ensure appropriate lighting in places such as streets and parking lots.