Lumens and lux are regularly confused. However, in very simple terms, lux is a measure of light given out by a light source, and lumens is a measure of illumination at a certain point or across a surface area. For instance, one luminaire or light source might be 3,600 lumens. This might provide 400 lux at 2m from the light source, but 800 lux at 1m from the light source.
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