Full daylight is 10,000-25,000 lux, and direct sunlight can get up to 100,000 lux.Ĭlearly, the end goal of scene/work lighting is to light up a working surface. A dark overcast day would be about 100 lux. Your office is probably around 400-500 lux. How does that equate to real life? Roughly speaking, 1 lux is about the equivalent of twilight. You’ll note the photographer is not measuring right at the light itself, but rather where the light is hitting.Ī Lux is 1 lumen covering 1 square meter. You’ve probably seen a photographer with a handheld light meter, putting it beside a model’s face and triggering the flash to see how much light is being splashed on the subject? That photographer is measuring in Lux (they use a different scale, but essentially they are measuring Lux). Lux is a much more accurate and desirable measurement than Lumens. Lux is the metric version of an older term you’ve probably heard of foot-candles. Lux is the measurement of light on a surface.
In the case of scene lights, however, pretty much no-one uses Candelas. They are quite common with warning (flashing) lights as that’s what SAE uses to measure a light. Very few, if any, manufacturers use Candelas for scene/work lights. Of course, whether they can tell the difference in intensity of the light on the ground is unknown. We have had customers buy a 5000 lumen light that is twice the price, thicker, heavier, with a worse warranty, than a 4700 lumen light, just because of that extra 300 lumens. So, everyone tends to use the “raw Lumens” method. Second, most manufacturers use this “raw” method so to have an actual Lumen measurement would mean your light is “dimmer” (on paper) than the competitors’. Why do manufacturers do this? First of all, because it’s easy – the manufacturer of the LED gives them the specifications for each LED so the manufacturer of the light simply adds them up and declares a “raw Lumens” number. So, in an extreme case, a 5000 lumen light can only really put out 2500 lumens.
As the LEDs warm up, they can grow dimmer if the heat is not properly removed. If there are any optics to ‘bend’ the light in any direction, those can consume over 30% of the light. For example, even a clear lens can suck up over 10% of the light output. The difficulty with this measurement is that there are many factors to the brightness of an LED. If Cree (or whatever LED manufacturer) says that each LED emits 100 lumens, and the light manufacturer puts 10 of these LEDs in a fixture, then the manufacturer somewhat erroneously claims a 1000 Lumen output. Rather, they are going by the LED manufacturer’s specifications for the LEDs themselves. What this means is that they haven’t actually measured the light coming out of a fixture. I would suggest that this is the most misunderstood term in the scene/work lighting world. With LEDs, this gets a bit tricky because most manufacturers use what they call “ Raw Lumens“. Let’s start with Lumens because that is what most people (and companies) use when comparing various scene lights.Īs you can see (hopefully) from the diagram above, Lumens show the total amount of light put out from a light source.
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