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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