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The Science of Lighting

It’s a world of mystery and wonder when it comes to off-road lighting. It’s something that can not only make you look like the next Shannon Campbell or Loren Healy, but can help you cut through the night if you choose correctly. However, with more and more fly-by-night companies popping up to sell you a lightbar “direct,” there are some things you need to consider before you purchase. That’s why we went to the experts over at Baja Designs to find out everything one needs to know about modern auxiliary lighting.

Moto Beginnings

In 1992, Alan Roach and product development engineer Stephen Mitchell were struggling to find a DOT-compliant lighting solution for their on- and off-road adventure bikes. Alan, being an engineer and enthusiast, created a halogen light system that would work with motorcycle electronics and ergonomics. This lighting upgrade quickly caught on and eventually rolled into the lighting company Baja Designs.


Working off of the adage, “with age comes a ‘cage,” many open desert bike riders transitioned to the trucks and buggies. One of the critical things they saw these four-wheeled vehicles lacking was lighting. Even though their bikes were smaller, their ability to see during the night was greater thanks to the lights Baja Designs created for them. These racers went back to Alan and the crew, asking them to create lights just as good as their motorcycle lighting for their trucks. They heeded the call and the four-wheel racer lights were created with the same technology and engineering, just with more room for more and bigger lights.


Halogen Lighting

Halogen lighting is the typical light you see on most vehicles that aren’t a premium brand. From headlights and fog lights to auxiliary off-road lights; halogen is the inexpensive go-to for lighting on nearly anything with wheels. Essentially, the way it works is that there is a tungsten filament that heats up and burns to produce light. Normally, that filament would evaporate away until either the bulb was black or it broke. Halogen creates a reversible chemical reaction cycle with the evaporated tungsten and allows it to stay at the same output until it eventually burns out, usually after 250 hours.


Getting light beyond the mid-range, what Baja Designs calls Zone 4, you need lights that are brighter than what even a 100-watt halogen is capable of. This can be where HIDs are a great option.

"Because (HIDs) produce more performance and a brighter light in the same power consumption of a halogen bulb," explains the operations manager at Baja Designs, "it opened up the world to different types of beam patterns. It allowed us to go beyond your traditional Euro beam and spot lights.”


What makes an HID perform better and brighter is that instead of a halogen/tungsten chemical reaction, it uses the electrical arc of two tungsten electrodes inside a tube filled with gas and metal salts. Once that arc starts, the metal salts become plasma and increases the light produced by the arc and begins to reduce the power consumption of the light. The ballast you have to use is needed to start the arc and maintain it, but the power required to drive the ballast is within the typical automotive electrical system including vehicles that used halogen lights originally. It also lasts longer than halogen with most systems lasting anywhere from about 3,000 to 5,000 hours.


“LEDs brought forth another huge advancement in performance and being able to design an optic that has a really good near field light but also getting distance out of the same package,” says Trent.

LED, or Light Emitting Diode, is the latest and greatest technology in off-road lighting at the moment. It uses a two-lead semiconductor light source that works like a p-n junction diode. If you don’t know what that is, imagine two plates sandwiching two types of conductive material. One material has electrons from the voltage applied to it while the other material has electron holes. When enough voltage is applied, the electrons recombine with the holes and produce energy in the form of photons; and then you get light.


“With halogen and HID," says Trent, "you weren’t able to combine multiple patterns into one product. You couldn’t have one eight-inch light that was both spot and driving – it was one or the other.” Despite how bright they are, LEDs are very small as you can see on this circuit board for the XL80 light. That yellow dot is the LED and is about the size of the fingertip of your pinky, yet it has the brightness and power to outclass many HID lights you see on the trails and deserts right now. Thanks to that, you can package a very powerful light system on your truck or rig without having to clutter it up.


The other bonus it has over HID is that it’s instant power up – you don’t have to wait for the plasma to build and warm up because there isn’t one. However, even LEDs, for their size and positives, have some drawbacks. LEDs are prone to producing more heat, and manufacturers have to take that into account when designing their lights. That includes the housings and circuit boards.

“It adds costs to the housings because it has to be waterproof, the LED can’t be exposed to outside elements, there are vibration issues,” continues Trent, “so from a consumer standpoint it’s instant power, can last 50,000 hours (if you buy from a reputable manufacturer), and you can buy less lights but can light up more areas.”

Flood vs. Spot

“There are two different patterns most consumers know: spot and flood,” explains Trent. “They don’t realize that companies like Baja Designs have a high speed spot, a standard spot, a combo, a wide driving, a wide cornering, and a flood.” A flood light is used as a work or scene light. It’s a very wide and circular light that’s about 60-degrees radius with its most intense light going from the very center to about 30-degrees. Essentially, it floods the area with light, but it’s not focused light.

“You never want to drive off of a flood light, even in a combo bar with a flood and a spot,” warns Trent. “You use a flood light to light up your horseshoe pit.”


Spot and High-Speed spot lights are used so you can see much, much further ahead. When you’re racing through the desert at triple digit speeds in the dark, you need to throw as much light down range as you can. Even in the dirt, the faster you go, the greater the need is for you to see to the horizon. You’ll use this in combination with a wide driving and/or cornering light. Not only will this type of light reduce the strain on your eyes because it gives a smooth transition to the spot lights, but it will also allow you to see the beyond the sides of the road or trail at speed.


‘Crawling Lights

Of course, there is more to off-road than just open desert racing. Rockcrawling and racing has its own unique challenges when it comes to lighting. It’s more about getting a good idea of what’s ahead of you and sometimes what’s just above your roof as you crawl around Johnson Valley and the like. It’s also about getting depth perception so you know how to approach a rock challenge or obstacle during the night. Then there is protecting that light.


The Right Light for Your Budget

If you’re looking to get your first set of off road lights, which way should you go? Should you still use halogen? Save a little more for HID? Or are LEDs the better investment? Trent recommends saving your money and getting a good, high quality LED setup.

“It’s really not worth investing into a halogen or HID, because you can get so much more performance out of an LED, and the longevity of the product makes it worthwhile.” With halogen lights, you get 250 to 300 hours of life out of them. With HID, it’s 3,000 to 5,000 hours. LEDs from a reputable company that engineers the product from start to finish will last up to 50,000 hours.


Even if you don’t buy from Baja Designs, you should buy from someone who is in the light business with a name that you can stand behind. Be it KC HiLites, Rigid Industries, Vision X, or Baja Designs, Trent stresses that you buy from someone who has a reputation and isn’t “selling ‘direct’ off of Facebook or Instagram. Basically, buying a very cheaply produced lightbar that isn’t even being driven at full power and could potentially be a danger to you."


What does he mean by “driven at full power?” Well, turns out many of those fly-by-night lightbar companies don’t drive the light at the full wattage they advertise. The brands listed by name above do drive its LEDs at 100 percent.

The Lumen Equation

There is one more thing to consider when it comes to buying LED lights. You’ll see the word “lumens” thrown around as a way to describe how powerful a light is. The reality is that lumen power doesn’t tell you the whole story. It doesn’t even tell you a portion of it. Yes, it is a measure of light, but it’s only a measurement of total light quantity and not the measure of its power.

Be warned, this requires a bit of math. A full sphere of light has a solid angle of 4 Pi Square Radians (or SR) which is 12.57-square meters, so if we have a light source that radiates one candela (cd) of power in all directions it will have the following: 1cd x 4 Pi SR = 4 Pi 1cdXSR = 12.57-lumens (basically, ignore the 4 Pi and multiply 1 candela times square radians; 4 Pi is mostly there to tell you how much of the sphere light you’re using). If you block half of that off (2 Pi), you’ll have 6.29-lumens in the direction light isn’t blocked but there’s still 1cd of power in that direction. You haven’t reduced the power you just reduced the direction the light can go in. You can kind of start to see how this can be abused or misinterpreted. You can say your light produces 400 lumens, but you aren’t saying where the light is going and how powerful it is in that direction.

Read our review of Rigid Industries' Dually LEDs.

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