When considering the performance of lights, Lux and Lumens are commonly referenced figures. But what do these terms mean? How can they assist in choosing driving lights, light bars, or bulbs?

To put it simply, Lumens refers to the overall amount of light emitted from a source. Such as a LED driving light. In contrast, Lux measures the brightness or intensity of the light when it reaches a particular object. Or an area situated away from the source.

The Difference Between Raw & Effective Lumens

When it comes to lumen figures, there are two types to consider: effective and raw. Raw lumens refer to the maximum potential light output of LEDs.

They are typically theoretical calculations rather than measured values. Thus, it is important to approach raw lumens with caution. Especially, when comparing light performance.

In contrast, effective lumens are more relevant as they are measured from an actual operating light. They are accounted for factors such as:

• The light’s design
• LED power output
• Heat management and optics

Real-world conditions ( electrical current availability and climate).

Effective lumen figures are always lower than their raw counterparts. But they provide a more accurate representation of real-world performance. They enable better comparisons between lights.

Lux – Its Association with Newspapers.

Lux is often used in combination with distance to determine the visibility of an object at a specific distance. For instance, a driving light’s beam may have a brightness of 1 lux at a distance of 950 meters.

This 1 lux brightness level is considered adequate for someone with 20/20 vision to read a newspaper. So it is a standardized measure of brightness.

As such, variations in performance between different manufacturers and models are typically observed in the distance at which the light can produce 1 lux.

For example, a less powerful light may only produce 1 lux at a distance of 500 meters. This means that someone could sit 500 meters away from the driving light. But still, be able to read a newspaper.

Yet, there is more to the story when it comes to comparing lux and lumen between different lights. Anyway, it is crucial to consider other factors that affect a light’s performance.

Factors That Impact the Brightness & Intensity of Light

The beam pattern is one of these factors that can impact light performance. For example, a laser pointer may provide 1 lux of brightness on a concentrated spot at a considerable distance.

But, this would not be particularly helpful for navigating through the dark. This is due to the minimal volume (lumens) produced by a focused beam pattern. So, a bedroom light bulb without a reflector produces an unfocused beam.

This would produce plenty of light volume (lumens) in your surroundings. But would be unable to illuminate anything beyond a short distance.

In the context of automotive lighting applications, there is a greater emphasis on:

• Balancing volume
• Intensity
• Adjusting the beam pattern to suit different situations.

For example, consider a standard 55w H4 halogen bulb used in a headlamp. It produces around 1,500 lumens. But most of which is directed toward the road.

Both the High and Low beams emit a similar number of lumens. But most people would describe the High beam as brighter than the Low beam.

This is because the Low beam covers the light accumulating in a wider area. But the High beam focuses the light into a narrower beam. It is to provide greater distance visibility.

Despite having similar lumens, the High beam produces a higher lux value at longer distances. The Low beam produces higher lux values towards the sides where it spreads more light.

Lux can also be used to state the width of a light beam. This is because the width is a type of distance, albeit one measured out to the sides.

For instance, a driving light can generate 1 lux of brightness at a width of 60 meters when measured at a distance of 400 meters. It implies that we should have enough illumination.

It is of a quality comparable to reading a newspaper, at a distance of 30 metres. That means there will be newspaper-quality illumination on both sides of the vehicle’s center 400 meters down the road.

When considering the performance of lights for off-road driving or country roads, it’s important to consider the lux and lumens figures and the beam pattern.

A combination of effective lumens and a beam diagram pattern provides a more complete understanding of light performance.

For these types of driving, a wide and uniform light spread is often more beneficial than a narrow and penetrating beam or hotspots, as it can help with early warning signs of wildlife and illuminate the track more evenly.

But, compromising on light performance is not necessary. Some premium LED driving lights, such as NV 9 Inches series. They offer a hybrid beam pattern that combines precision optics and high-powered LEDs.

They provide ample light to the sides and down the road. They produce a robust and long-distance beam. It has a brightness output of 8,400 effective lumens and a lux measurement of 1 at a distance of 480 meters.

NV’s driving lights are tested at their facility in Guangzhou, China. It is an in-house photometric light lab to measure lumen and lux figures and beam patterns. NV’s engineers are able to fine-tune the performance of their driving lights. They match it to real-world conditions