Introduction

In the realm of lighting, the measurement of light intensity is crucial for creating optimal lighting conditions. Two commonly used units for this purpose are lux and footcandles. Converting between these units is essential for ensuring accurate lighting design and compliance with industry standards.
What is Lux?
Lux is the SI unit of illuminance, which measures the luminous flux per unit area. It represents the amount of light that falls on a surface and is often used in indoor lighting applications.
What are Footcandles?
Footcandles (fc) is an imperial unit of illuminance, which measures the luminous flux per unit area in lumens per square foot. It is commonly used in outdoor lighting applications and in the United States.
Conversion Formula
The conversion formula between lux and footcandles is:
1 footcandle = 10.76 lux
or
1 lux = 0.0929 footcandles
Factors Affecting Conversion
When converting between lux and footcandles, it is important to consider the following factors:
- Surface Reflectance: The reflectance of the surface on which the light is falling can affect the intensity of the light and, consequently, the conversion.
- Distance from the Light Source: The distance between the light source and the surface can affect the amount of light reaching the surface and, thus, the conversion.
- Type of Light Source: Different types of light sources have different emission characteristics, which can influence the conversion.
Applications of Lux and Footcandles
Lux and footcandles are used in a wide range of applications, including:
- Indoor Lighting Design: Ensuring adequate lighting levels for comfortable and functional spaces.
- Outdoor Lighting Design: Designing streetlights, security lighting, and landscape lighting to provide appropriate visibility.
- Industrial Lighting: Optimizing lighting conditions in factories, warehouses, and manufacturing facilities for safety and efficiency.
- Photography and Videography: Calibrating lighting equipment to achieve the desired exposure.
Conversion Tables
To facilitate quick and accurate conversions, here are some useful tables:
Lux | Footcandles |
---|---|
10 | 0.929 |
20 | 1.86 |
50 | 4.64 |
100 | 9.29 |
200 | 18.6 |
500 | 46.4 |
1000 | 92.9 |
Conclusion
Converting between lux and footcandles is a critical aspect of lighting design. Understanding the conversion formula and considering the factors that affect it allows for precise calculations and the creation of optimal lighting conditions. By utilizing the provided tables and strategies, professionals can confidently make conversions and achieve accurate lighting solutions.