Many people know that it is much easier and less expensive to measure the lux output of a light source instead of its lumen output, but lux lies where lumens doesn’t!

The measure of the quantity of light as seen by people is called lumens. If you have twice as many lumens, you have twice as much “light”. The lumens measurement, if done correctly, is independent of where in the beam or how far from the light fixture the measurement is made. The true, most honest metric of light output by an underwater light is the number of lumens exiting the fixture and traveling into the water.

Lumens in this sense are difficult to measure. Either the light output in all directions needs to be measured and added up, or a device called an integrating sphere needs to be used effectively adds all of the light in real time. Since this integrating sphere is quite expensive, not many light companies invest in one and therefore measure the light output of their lights with a simple and inexpensive lux-meter instead (that’s why you see lux measurement on spec sheets way more than you see a Lumen measurement).

Lux is just lumens per square meter. If you have a bright, narrow, highly focused spot light, you will get a very high lux values, but this really does not tell you much about how much total light the fixture is putting into the water. Let’s give you an example, if you need to change your tyre at night at side of a dark road, would you use a flash light with flood reflector or a laser?  Of course a flood light. However if you put a lux-meter by these two and measure them up, the laser will blow away the flood light as far as light output goes. That’s what I meant by saying “lux lies”!

DeepSea Power & Light specify all of their lighting products by lumen output. You can depend upon DeepSea Power & Light products to be accurately specified, performing to specification and suitable for your intended application. Contact BlueZone to let us assist you with a selection of DeepSea Power & Light products.