Understanding Light Measurements: Lux, Footcandles, and More

Light measurement can seem complex at first, but understanding a few basic concepts can help you make sense of the readings you get from your Luxmeter app.

The most common unit of illuminance (the amount of light falling on a surface) is the lux. One lux is equal to one lumen per square meter. For reference, a full moon on a clear night provides about 0.1 lux, standard office lighting ranges from 300-500 lux, and direct sunlight can reach up to 100,000 lux.

In the United States, footcandles are often used instead. One footcandle equals approximately 10.76 lux, and it represents the illuminance on a surface that is one foot from a uniform point source of light.

When using Luxmeter, you can easily switch between these units depending on your needs and preferences. Understanding these measurements can help photographers find the perfect lighting conditions, ensure plants receive adequate light, or verify that workplace illumination meets safety standards.