When it comes to our rigs, we always want it bigger, tougher, brasher, faster and stronger. It goes without saying that as a supplier of after-market LED driving lights, we’re in a pretty good position to say that most also want it brighter. There’s something inspiring and exhilarating about an off-road vehicle with the full complement of lights blazing that gets the heart and adrenaline pumping.

How Can a 100W Lamp Give Better Performance Than a 150W Lamp?

This little nugget is a question that we get asked all the time. Logic would tell you that it’s impossible and counter-intuitive. In our experience, most people default to the higher wattage lamp, assuming they can afford it. The higher the wattage, the brighter the light, right? As it turns out, it’s not always that simple. There are so many intricacies and technical factors that go into the determining the output of a lamp that it can be incredibly confusing to understand what you’re getting and how it will perform on the road. Confused? Great! We’re going to run through some of the factors that you need to be aware of so that you know what you’re getting

1. LED, Halogen or HID Lamps?

The technology you’re running will have a significant impact on the performance. The reason for this is simple: Wattage measures energy going into the lamp, but not all that power is converted into light. Different bulbs utilise energy in varying ways that will impact the light output. Halogens emit significant amounts of heat to the front of the lamp, while LEDs push theirs out the back. HIDs create very little heat at all. The more energy lost as heat the less remains for light.

Read more about HID vs Halogen vs LED driving lights

2. Watts Vs Lumens

Ok then, a win for HIDs, correct? Not so fast. Not all light emitted is visible. Given that the point of LED headlights is to see the road, infrared or other wavelengths outside of the visible spectrum are hardly going to be of much assistance when the sun is sinking, and the going is getting tough. Theoretically, this means that you could have a lower wattage lamp that is brighter than a higher wattage one due to greater efficiency in converting the energy input into visible light.

This begs the question: how can you tell what the actual light output will be from your lamp? Rather than looking at the wattage, you should be looking at Lumens – a measure of luminous flux, better known as the amount of visible light being emitted by a source.   

3. Raw Lumens Vs Effective Lumens

Just when you thought we had it all sorted… Apparently, lumens ain’t lumens. The raw lumen rating that you find on the package is telling you the results that the manufacturer obtained from testing the lamp in a laboratory while operating at peak performance under ideal test conditions. As a customer, what you want to know is how the lamps are going to function as a system. How an individual LED performs in a lab is not necessarily going to tell you how it will function together with 29 other LEDs on a PC board operating as a lamp now, is it? Under those practical conditions, many manufacturers will have their LEDs running at below peak output to ensure they last longer and don’t burn out or overheat. For this reason, you need to be looking at effective lumens if you are going to get a true idea of the actual light output from your product.

Fabulous! I’ll just check the effective lumens, and we’re good to go! Umm… Sorry to be the killjoy. Once again, things are not entirely as they seem. While effective lumens will certainly give you a very good indication of the brightness, it doesn’t tell you how that light is controlled. Not all LED driving lamps are created equally. The materials and construction of each product can subtly affect the true level of light that reaches the target. Frustrated yet? Read on!

4. Lux and Lumens

The most accurate and objective measure of actual, visible light output is lux. Lux is the measure of Lumens per square metre at a given point. The more effectively the lumens emitted are controlled and concentrated, the higher the lux. Put simply, lumens tell you how much light is emitted from the lamp, whereas lux tells you how much light actually reaches the desired distance. Clearly, this is what we’re looking for when we’re assessing the right product for our vehicles.

Ordinarily, lux is measured in a laboratory, with measurements taken at a 25m and extrapolated out to greater distances. While this is a good indication, the only way to gauge the performance with absolute accuracy is to take measurements in a live situation on the road. The best manufacturers and suppliers will run their products through this kind of test so that they can understand the light patterns of their products under real conditions.

As a crude estimate, you should be able to read a newspaper easily at 1 lux. Determining the distance possible will give you a reasonable idea of how efficient your lamp is.

Read more about Lux Vs Lumens.

It took us a little while, but thankfully, we got there! With all this in mind, you can easily see how a higher quality, better-constructed lamp could give brighter light than a higher wattage competitor. In the next part of this series, we’ll look at other factors that may affect the light emission from your LED driving lights, so stay tuned!