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. Lux – this is the measurement of how much light hits a surface to illuminate it.Candela – this is the light that a fixture emits in a certain direction.Lumens – this is the total light that a lighting fixture emits in all directions.There are really 3 main ways to judge the brightness of a light

While we understand why people are asking this, this is really the wrong way to judge a light’s output. Almost daily, we get questions about how many Lumens a scene/work light emits.

Lumens to candela