Lumens, Lux, and Candela EXPLAINED | Diode Dynamics

Introduction

This tutorial explains the differences between three key measurements of light output in automotive lighting: lumens, lux, and candela. Understanding these measurements is essential for evaluating the performance of LED bulbs and lamps in vehicles. By the end of this guide, you will have a clearer idea of how these values are measured and what they signify for automotive lighting.

Step 1: Understanding Lumens

• Definition: Lumens measure the total amount of visible light emitted by a source.
• Common Use: Many automotive companies primarily use lumens to advertise light output due to its accessibility.
• Limitations: Relying solely on lumen values can be misleading because it does not indicate how well the light is focused in a specific direction.

Step 2: Exploring Lux

• Definition: Lux measures the intensity of light that hits a surface, taking into account the area over which the light is distributed.
• Application: Lux is important for determining how well illuminated a specific area is, such as the road directly in front of your vehicle.
• Calculation: One lux is equal to one lumen per square meter, making it a useful metric for evaluating light performance on surfaces.

Step 3: Delving into Candela

• Definition: Candela measures the intensity of light emitted from a source in a specific direction.
• How It’s Measured: At Diode Dynamics, candela is measured using a goniometer and light tunnel, which assess thousands of output points to determine focused light projection.
• Significance: Candela provides a more accurate representation of how much light is directed in a beam pattern, making it crucial for automotive lighting performance.

Step 4: Comparing the Measurements

• Key Differences:
  • Lumens: Total light output, not direction-specific.
  • Lux: Light intensity on a surface, area-dependent.
  • Candela: Directional light intensity, focused beam analysis.
• Practical Tip: When choosing automotive lighting, consider all three measurements to ensure optimal performance for your needs.

Conclusion

Understanding lumens, lux, and candela is essential for evaluating automotive lighting effectiveness. While lumens give a general idea of light output, lux and candela provide insights into how that light performs in real-world conditions. For better lighting choices, analyze all three measurements when selecting LED bulbs or lamps for your vehicle. If you have further questions, feel free to reach out to Diode Dynamics for expert assistance.