1. What is Image Brightness?

Image brightness is a photometric measure of the luminous flux per unit area of light passing through or emitted from a surface. It's typically measured in lumens per square meter (lm/m²).

2. How Does the Calculator Work?

The calculator uses the brightness formula:

Where:

• \( \text{Flux} \) — Luminous flux in lumens (lm)
• \( \text{Area} \) — Surface area in square meters (m²)

Explanation: The equation calculates how much light is distributed over a given area, determining the perceived brightness of an image or surface.

3. Importance of Brightness Calculation

Details: Calculating image brightness is essential in photography, display technology, lighting design, and various scientific applications to ensure proper illumination and visibility.

4. Using the Calculator

Tips: Enter the luminous flux in lumens and the area in square meters. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between brightness and luminance?
A: Brightness is the perceived sensation of light, while luminance is the measurable photometric quantity. Brightness is subjective, luminance is objective.

Q2: What are typical brightness values?
A: Typical values range from 1-10 lm/m² for dim lighting to over 1000 lm/m² for bright displays or sunlight conditions.

Q3: How does brightness relate to exposure in photography?
A: Higher brightness values generally require shorter exposure times to avoid overexposure in photographic images.

Q4: Can this calculator be used for screen brightness?
A: Yes, if you know the total luminous flux emitted by the screen and its area, you can calculate its brightness.

Q5: What factors affect perceived brightness?
A: Besides the actual luminous flux, factors like ambient light, color temperature, and human visual adaptation affect perceived brightness.