The word “lumens” gets thrown around a lot in the lighting world. Maybe you’ve heard of theoretical lumens and effective lumens. But what are the differences? And what are effective lumens, and why are they the standard to which you should measure LED lights? Let’s take a look.
Theoretical / Raw Lumen
As with all things theoretical, a theoretical lumen is a measure of light output in a perfect world. In other words, the maximum performance you could theoretically get out of the LED light projection if nothing else impacted it. This might include things such as optics, reflectors, or heat.
For example, a car manufacturer may say their car can achieve 70 miles per gallon (MPG) of fuel economy from their new model. While that might be true, it’s only possible if you drive at 20 MPH, with no hills, no wind resistance, and never change gears. In the real world, outside factors always impact the output. The real-world fuel economy might be more like 35 MPG because there are a host of outside factors that impact the performance. Therefore, the higher rating shouldn’t be taken as the actual fuel economy because few people only drive 20 MPH on flat ground, etc.
The same can be said for lights. When a lighting company says it has 7,000 lumens, if it’s theoretical or raw lumens, that isn’t the true amount of light. That’s how much it could produce.
Cold Lumen
The cold lumen rating is measured when the LED light is first switched on. It will continually decrease until the LED light has reached its operating temperature. This rating is always lower than the theoretical lumen rating as it considers outside factors affecting the light output.
Effective Lumens
Once the light has reached its operating temperature, we measure the lumen output in effective lumen or eLumen. This is the most reliable, honest rating. The reading is taken once the light has been operating for two hours. It will show a decrease from the cold lumen due to physical-related losses in optics, reflectors and heat. This is the light that you will be working with. And as such, is the most reliable reading to consider when looking to purchase new LED lights for your vehicle.
Effective Lumens and What to Consider When Looking at LED Lighting
Checking the effective lumen value is a priority. If these are not listed on the supplier’s information, be aware: the light may not give the output stated. This is something we run into while testing the competition’s lights.
Also check the company’s credentials. Do the products carry an IP rating (ingress protection) and an EMC rating? (electromagnetic compatibility)? This will give you an indication of the quality of the goods and ensure you get a light which gives you the output you need and stands up to the harsh environment your vehicle operates in.
TYRI: eLumens
All TYRI lights have their eLumen ratings clearly listed to you know exactly how much light output our lamps have. In addition, each light’s product data sheet lists the IP rating (such as IP68) to let you know just how waterproof the lights are. We also have the EMC, salt spray, vibration, shock, and ECE data. This lets you choose the perfect fit for your application.