Light Clarification – What is the difference between Lumens, Lux and Watt?
When buying a new luminiaire it is easy to get confused about the different terms that are used. Below you will be able to read more about three of the terms, Lumens, Lux and Watt.
Things to remember:
- Many manufacturers promise a much higher amount of lumen than the product delivers.
- Look for Lumens not the amount of Watts
- Lumens measure total amount of light output
- Lux measure light intensity
- Lumens does not equal perceived light quality
Lumens and light
Lumen is a unit of light, which is also known as Luminous flux.
Lumens (LM) are a measurement unit, which tells what the total amount of light emitted from a luminaire. You can roughly say that the more Lumens the brighter the light.
When we test and compare our products, we use Lumens to see the total amount of light output. But Lumens will only show us a part of the picture. Producing and creating a perfect beam pattern does not reveal enough information to show how the light output is created. For this we need to use a lux meter.
When we measure the amount of lumens, we use a highly specialized light sphere. This is to ensure that each batch is perfect and delivers what we promise.
Most luminaires drop in Lumens and promise a higher Lumen output than they can achieve. To prevent this in our products, we perform light tests on all of our products to ensure that the lumen value is correct.
Lux and intensity
Lux is a unit of light measurement where the area is also taken into account. 1 lux equals 1 Lumen/m2, in other words – light intensity in a specific area.
Lux is used to measure the amount of light output in a given area – one lux is equal to one lumen per square meter. It enables us to measure the total “amount” of visible light present and the intensity of the illumination on a surface.
We use lux because it is an efficient measurement for determining what we see as the brightness of a beam. If the light output is focused on a small area, we see this as very bright light. If the light output is spread in a wide beam over a greater area, we experience this as a weaker light. This is why we use reflectors machined out of aluminum, and high quality optics to control the path of light, creating the desired beam pattern with a minimum loss of light.
Can I use Watt to determine the power of a luminaire?
Watt is a unit for power consumption.
The short answer is no, Watt shows how much energy the product consumes, not how much light output (lumens) it provides.
It is also worth knowing that 1Watt halogen, 1Watt fluorescent and 1 Watt LED do not produce the same amount of light. The LED Chip is more efficient and will convert much more energy to light than the halogen or fluorescent luminaire or lamp.
It is important to keep in mind that the more power consumed the more heat is produced, and heat will always result in a loss of energy. That is why our luminaires are equipped with a solid metal heat sink, which uses the entire device to efficiently divert the heat throughout the core structure. This will ensure a stable high light output for a much longer period, and prolong the lifetime of the LED Chip.