Light Conversion Calculator | Luminance, Intensity, Illumination
💡 Light & Image Converters
Light Conversion Calculator | Luminance, Intensity, Illumination
Understanding light is essential in physics, engineering, photography, and lighting design. Often, you may need to convert between different measures of light such as Luminance (cd/m²), Light Intensity (candela, cd), and Illumination (lux, lx). The Light Conversion Calculator makes this fast, accurate, and easy to understand.
Why Light Conversion Is Important
- Photography & Cinematography: Proper light levels ensure correct exposure.
- Engineering: Helps design lighting systems in buildings, streets, and offices.
- Science & Research: Accurate light measurements are crucial in experiments.
- Education: Students can learn relationships between different light units.
Key Light Parameters & Formulas
Here are the most important formulas for converting between light quantities:
| Quantity | Unit | Formula / Relation |
|---|---|---|
| Illuminance (E) | lux (lx) | E = I / d² Where I = luminous intensity (cd), d = distance from source (m) |
| Luminous Intensity (I) | candela (cd) | I = E × d² Where E = illuminance (lx), d = distance from source (m) |
| Luminance (L) | cd/m² | L = I / A Where I = luminous intensity (cd), A = area of emitting surface (m²) |
| Illuminance from Luminance | lux (lx) | E = L × π Where L = luminance in cd/m² |
How the Light Conversion Calculator Works
- Select the type of quantity you want to calculate: Luminance, Intensity, or Illumination.
- Enter the known values such as distance (d) or surface area (A).
- The calculator automatically applies the correct formula to give the result.
- Instantly obtain the converted light value in the desired unit.
Step-by-Step Example 1: Calculate Illuminance
Problem: A lamp has a luminous intensity of 500 cd. Find the illuminance at a distance of 5 meters.
Formula: E = I / d²
Solution: E = 500 / 5² = 500 / 25 = 20 lux
Step-by-Step Example 2: Calculate Luminance
Problem: A small LED has luminous intensity I = 120 cd and emits light from a surface area of 0.02 m². Find luminance.
Formula: L = I / A
Solution: L = 120 / 0.02 = 6000 cd/m²
Step-by-Step Example 3: Calculate Luminous Intensity
Problem: The illuminance on a desk is measured at 400 lux at a distance of 2 meters. Find the intensity of the light source.
Formula: I = E × d²
Solution: I = 400 × 2² = 400 × 4 = 1600 cd
FAQs – Light Conversion Calculator
1. What is the difference between illuminance and luminance?
Illuminance (lux) is the amount of light falling on a surface, whereas luminance (cd/m²) is the amount of light emitted from a surface.
2. Can this tool convert between lux and candela?
Yes, using the distance formula E = I / d².
3. Do I need to know formulas to use it?
No, the calculator applies all formulas automatically; you just input the known values.
4. Is it suitable for students and engineers?
Absolutely. It’s useful in physics labs, engineering, and lighting design projects.
5. Can it handle multiple light sources?
Yes, for multiple sources, calculate each separately and sum the illuminance values.
6. Can I calculate luminance from a known intensity?
Yes, using L = I / A formula.
7. Can this calculator convert to SI and CGS units?
Yes, it supports all standard units like lux, candela, and cd/m².
8. Does distance affect illuminance?
Yes, illuminance decreases with the square of the distance (inverse square law).
9. Can it be used for photography lighting?
Yes, it helps determine exposure and proper light placement.
10. Is this tool free and online?
Yes, it’s completely free and works in any modern browser.
