Illumination Units: Lux vs. Foot-Candles

Lux vs. Lumens

• Lumens: How much total light is coming out of the bulb?
• Lux: How bright is the light on a specific surface (like your desk)?

Comparison

• 1 Foot-candle is the light from one candle on a surface one foot away.
• 1 Lux is the metric version (one lumen per square meter).
• 1 Foot-candle ≈ 10.76 Lux

Recommended Light Levels

• Storage Room: 50 Lux
• Office Work: 500 Lux
• Precision Surgery: 10,000+ Lux

Key Takeaways

• Lux decreases rapidly as you move away from the light source
• "Bright sunlight" is about 100,000 Lux
• Use a light meter app for quick home checks