When you’re shopping for lighting, look for charts that make comparisons between lumens and traditional wattage. Light, the instant it is emitted, travels in all directions at once, and, as we mentioned above, many of those particles of light don’t strike the surface of what we are looking at. Lumens, on the other hand, is a measurement of the light that a light source emits. RELATED: Solved! This is the Best Bathroom Lighting Lumens is a measure of luminous flux. A tightly-focused flashlight beam will produce a greater lux value than an ordinary table lamp, even if the bulb is the same in both. Lux can vary depending on the light source, the distance the object in question is from the light source, how dark the surface of the object is, the width of the beam of light, etc. “X” number of photons may be emitted from a light source, but some number of those photons never make it to the surface of something you’re looking at, or they are absorbed by the surface. Lux is a measurement of the amount of light that falls on a surface, which differs from the amount of light that is emitted from a light source.