Lux vs. Lumen: Simply Explained

When describing dive lights, lux and lumens are important specifications that provide different information about the light output and performance of the dive light:

  1. Lumens (lm) in Dive Lights:

    • What it measures: Lumens indicate the total amount of visible light emitted by the dive light source in all directions. In the context of dive lights, lumens tell you how bright the light source is without considering the distance or how that light is distributed.
    • Application: Lumens are often used to describe the overall brightness of a dive light. Higher lumens generally mean a brighter light output, which can be advantageous in low-visibility underwater environments or for illuminating larger areas.
  2. Lux (lx) in Dive Lights:

    • What it measures: Lux measures the intensity of light at a specific distance from the dive light source. It quantifies how bright the light is at a particular spot underwater. In this context, lux is particularly useful for understanding how well a dive light can illuminate objects or details at a specific distance.
    • Application: Lux is more focused on the practical performance of the dive light. It helps divers determine how effectively the light can penetrate the water and provide adequate illumination at the distance where they need it. A high lux rating indicates that the light can maintain its brightness even at greater depths.

In summary, when describing dive lights:

  • Lumens indicate the overall brightness of the light source, which is helpful for general brightness comparisons between dive lights.
  • Lux provides information about the intensity of the light at a specific distance from the dive light, helping divers understand how well the light will perform in terms of visibility and object illumination underwater.

When choosing a dive light, it's important to consider both lumens and lux ratings to ensure that it meets your specific diving needs, including the depth and distance at which you plan to use it.

Halcyon uses LUX to describe diving lights because this provides a gauge of intensity at a given distance. This gauge is more relevant for use while diving and specifically for signaling your buddy while diving.

Halcyon typically tests lux output at one, three, and five meters (about 3, 10, and 16 feet respectively) from the light. These distances are useful when comparing dive light intensity.

It’s worth noting; a lux measurement that is taken very close to the light source will be higher than a lux measurement taken at a farther distance from the same light source. This is because the light diffuses as it gets farther from the source. Given this, you can think of lumens as the amount of light available and lux as the lumens that are actually arriving at the target.