Upgrading the headlight bulbs or assemblies on your car or truck is a great way to improve your ability to see long distances while driving. Though many buyers focus on the amount of light produced by the bulb, ensuring that the new solution provides a proper beam pattern is crucial to your safety and that of other people on the road. Let’s discuss beam patterns and their implications for long-distance vision.
Parts of a Headlight Assembly
There are two popular types of headlight assemblies: projector and reflector styles. A reflector headlight assembly typically features a large metallic bowl that surrounds an incandescent bulb. The shape of the bowl is designed to focus the light from the bulb in a relatively narrow beam. In a projector assembly, the bulb is placed in a compact bowl that’s 2 or 3 inches in diameter. A relatively thick lens on the front of the assembly focuses the light. These designs often include a metal plate between the reflector and the lens to provide a sharp cut-off that keeps the output from blinding oncoming drivers.
Different Bulb Upgrade Options
When shopping for upgraded bulbs for your lights, you have the option of high-output halogen, HID and LED. In the incandescent halogen market, bulb sets like the Osram Night Breaker Unlimited, Sylvania Silverstar Ultra and GE Nighthawk Platinum can increase light output by as much as 29% over a standard halogen bulb. When it comes to HID kits and LED bulbs, there are quite literally thousands of options. It is worth keeping up with reputable review websites and YouTube channels to see how technology is advancing. As of this writing in early 2020, there are finally LED bulbs that provide more light output than a 35-watt HID kit.
What Does More Output Mean?
Ignoring the importance of beam pattern for just a minute, more light output means that whatever beam pattern is created will be brighter. Does this automatically mean you can see farther? Well, if your headlights aren’t adjusted properly, then no. Imagine if your lights are angled down a bit too much. All that light will only make the area in front of your vehicle brighter. Logic dictates that you should aim your lights a little higher in order to see farther. While this makes sense, you now run the risk of blinding oncoming drivers. This practice is extremely dangerous and could lead to you getting a ticket from the police.
What Is Headlight Beam Pattern?
Every light source emits light in a pattern. A candle, for example, produces a relatively spherical light source, lighting the area to the sides and above evenly. If you put a mirror beside the candle, you bounce that light out evenly in all directions.
If we now look at a flashlight, you can see that the light output pattern is more of a cone than a sphere. Little to no light is radiated behind or directly above, below or to the sides of the flashlight. Understanding this is fundamental to understanding how headlights work.
The headlights in most North American vehicles are designed to focus light in what is called a DOT pattern. This pattern, most commonly visible with projector-style light assemblies, has a sharp and defined upper cut-off that prevents oncoming drivers from being blinded. The pattern includes a step around the center of the output to put more light on the road on the right, so you can see farther without affecting oncoming traffic.
Light Intensity within the Beam Pattern
While the upper cutoff is crucial to keeping you and the other drivers on the road safe, the amount of light in different parts of the output pattern is also crucial. For optimum long-range visibility, you will want a relatively small and focused hot-spot in the upper center of the pattern. If there is too much light around the middle of the pattern, the road directly in front of the vehicle may be too bright, causing the iris in your eyes to contract slightly and reduce your long-distance vision.
How to Choose the Right Headlight Upgrades
If you are dealing with a reputable mobile enhancement retailer, ask if they can test-fit the planned light upgrade in your headlights before you finalize the purchase. Look at the light output on the wall of the shop and compare it to your factory lights. Make sure that any cut-off remains sharp and that the hot spot remains centered.
