Low and high beams headlight: main features

Susan Fernandez January 01 2022

How do headlights work?

A headlight is a lamp on the front of a vehicle that illuminates the way in which this car is moving. Headlights are usually found on cars, motorcycles or trucks.

It is constructed from a headlight that is used in the lower beam, which consists of a yellowish lamp for illuminating objects ahead, and in the upper beam used to illuminate eyes in front.

Another characteristic element of this equipment is the light sensor on each side of the focal point of light, sensitized to infrared light or are not sensitive at all when exposed to ultraviolet rays.

The distance between these lights must be constant so as not to hurt your eyes with blinding headlights while you are moving at night.

Neither can we get close enough for them to blind us if we move towards it: because they should rise and fall slightly so that our sight remains clear and safe without too much difficulty. They could always go out if we stayed fixed on our track because the light would be too high.

At night, your headlights are not visible to other drivers. This makes it harder for them to see you on the road if you are in a particular section of it or making a curve. That is why you should always have your lights on when it is darker outside, whether day or night.

What is a low beam headlight?

Low beams, also called low-beam headlights or passing lights, are the standard headlights on a vehicle. Their job is to provide illumination for bad roads and to allow drivers to see objects in front of them at a distance so they can maneuver safely and avoid collisions.

How does it work?

The low beam headlight is created by a small halogen bulb mounted inside an adjustable reflector.

How many types of low beam headlights are there?

There are two kinds of low beams. These are the composite reflectors and parabolic reflectors. Each has advantages and disadvantages, especially at certain angles to other vehicles on the road.

The illumination patterns for each headlight type are also different. This means that some cars may have better visibility than others at certain spots or during certain times of day, depending on what kind of light they produce.

When would you use low beams?

Drivers should turn on their low-beam headlights when they are driving in locations where street lights provide most of the illumination. For example, most cities have purposely designed streets with low light levels at night to make it easier for drivers to see pedestrians and other vehicles.

However, many city streets also have relatively dark areas that require drivers to use their high beams. When driving outside of urban areas, drivers should always keep their headlights set on low beams if there isn't another car within 500 feet (150 meters) ahead of them because high beams will only blind approaching traffic, not help it see better.

What is a high beam headlight?

High beams, also known as full-beam or driving lamps, function like extra powerful versions of low beams.

High-beam headlights produce much more light than regular ones because the purpose of the high beam setting is not simply to illuminate areas in front of a driver but rather to throw as much light as possible directly forward in order to see well far down the road when there is no street light or other source of illumination.

High beams are best for unlit rural or dark roads because they allow a driver to see long distances down the road and spot upcoming hazards sooner.

How does it work?

In the past, high beam headlights were created by attaching two small filament bulbs to a switch so that they could be turned on and off simultaneously. Nowadays, nearly all new cars have one large bulb inside a reflector housing for each headlight located at an angle in front of the vehicle so that they can provide illumination to both sides of the road.

Are there different types of high beam headlights?

Modern high beam headlights produce different illumination patterns depending on the size of the vehicle. For example, cars produce a long-range beam that provides good visibility for driving at speeds up to 60 miles per hour (100 kilometers per hour).

However, trucks and SUVs have higher beams with greater light intensity because they are designed for slower speeds. These lights also shine lower along the road so that drivers can spot hazards sooner.

When would you use high beams?

Drivers should switch on their high beams whenever they can't see what's ahead of them in the distance or when lights from other vehicles make it difficult to see clearly. When driving on curvy roads, turning off the high beams can help you see corners better, but keep them on when there isn't another vehicle within 500 feet (150 meters) in front of yours.

High-beam headlights should always be turned off while you're coming up behind another car. The bright light will temporarily blind its driver and make it impossible for her to see what's in front of her. Plus, you'll put other drivers on the road at risk too.

High beams are also helpful when driving in fog or other low-visibility conditions. Turning them off will only make it harder for you to see what's ahead and can even blind drivers coming toward you.

Are there any Traffic code regulations for using low or high beams headlights?

High beams should be turned on when you approach an oncoming vehicle and then dimmed as the car passes. High beams should never be used when following or driving directly in front of another car because they can temporarily blind other drivers. If a driver coming toward you has their high-beam headlights on, flash your own lights to let them know there is a problem and avoid turning the high beams off suddenly.

Traffic code prescribes that drivers must keep their low beams turned on when driving within 500 feet (150 meters) of an approaching vehicle or when they're following another car closer than that. Drivers should also turn on the low beams whenever it is raining, snowing, foggy or smoggy, and whenever there are other cars with their headlights on nearby.

High beams are usually used for between one-half hour after sunset one-half hour before sunrise unless there are street lights. For safety reasons, drivers should only use high beams at night when there isn't any vehicle within 500 feet (150 meters) in front of them or within 200 feet (60 meters) behind them because bright light from the high beams can temporarily blind other drivers.

The difference in lumens and power

Low beams headlights require less power than high beams, but they also produce less light. When shopping for replacement headlights, it's important to look at the bulb type and not just the number of lumens it produces. A pair of low-beam headlights can produce up to 2,000 lumens while a set of high-beams is closer to 4,000 lumens.

Low beams headlight can run on both 6 or 12 V and use 45-60 Watts, while high beams headlights can work on 12 V and require 75-90 Watts.

Can low and high beams headlights be in the same bulb?

Yes, some cars use a single bulb for both low and high beam functions. These headlights are called dual-filament bulbs because they have two filaments inside. One filament is used to provide illumination for driving at speeds up to 60 miles per hour (100 kilometers per hour) while the other provides greater illumination when driving faster or when approaching another vehicle.

How can I tell if my headlights are aimed correctly?

Most new cars come with lights that are properly aligned by the manufacturer so there's no adjustment necessary on your part.

However, you can still check to make sure your car's headlights aren't too high or too low by standing in front of your hood and looking down at the road surface about 25 feet (7.6 meters) in front of you and 25 feet (7.6 meters) to each side. This distance is important because it's the distance at which your headlights will illuminate a vertical object that is set 20 feet from the edge of the road.

If you can't see those surfaces, then your headlights are too high. If they do illuminate those surfaces, turn off the engine and check one more thing: shining your lights toward a flat surface such as a wall or garage door, look at where the center point of the beam hits it. If it's below center-point height, meaning if there isn't one bright spot but rather two spots closer together with a dark area between them, then your headlights are aimed too low and need to be adjusted.

If you're not sure how to aim your headlights, ask at your local dealership. Most dealerships can also inspect your headlights and replace any that are damaged or aimed incorrectly for free during regular maintenance.

What about High-Intensity Discharge (HID) lights?

Some newer cars come with high-intensity discharge (HID) headlights, which provide more light than halogen lights but use more power. HIDs produce three to five times as much light in the same space as halogen bulbs. They don't require a separate reflector; instead, they reseat the light generated by the filament inside the lens through a complex process similar to an electronic ballast in fluorescent lighting. The result is not only more light but better-quality light.

How do fog lights contribute to nighttime safety?

Fog lights are low beams that can help as much as high beams during poor visibility such as heavy rain, snow, or fog. They use the same reflectors and lenses as regular headlights but often have yellow lenses so they won't blind oncoming drivers at night.

Their position is usually lower than regular headlights to send light shining toward the ground, where it will scatter less in mist or fog. The idea is not so much seeing what's ahead of you but allowing other drivers to see your car better in conditions where your tail lights might otherwise fade into the background because of low contrast with the road.

The correct use of fog lights is important for nighttime driving because being seen is sometimes more important than seeing obstacles. To ensure you're using your fog lights in a way that helps others on the road see you, consult your vehicle's owner's manual for specific directions.

How much do you spend when maintaining headlight bulbs?

Replacing your low beams (halogen) can cost about $80, while high-beam (xenon) replacements are closer to $150.

They're both fairly affordable and easy to replace in most cars and trucks, but it's important that the replacement bulb matches the original equipment specifications for each headlight assembly in order to keep drivers safe at night and during bad weather conditions. Even if a new bulb works in one position, it may not work in the other light so sometimes pairing up one left side with the right side is necessary.

How do I know if my headlights need to be replaced?

The best way to check whether your headlights are still working properly is by looking at them after you've turned on the car and letting them warm up for several minutes. Check out the headlight housing to see whether both light beams appear clear and bright without any fog or visible obstructions blocking their path.

If you notice a difference in brightness, coloration, beam sharpness, or clarity then one of the lights may be too dim to adequately illuminate the road or it may no longer function correctly. You should also look closely at each headlight with your parking lights. If one isn't as bright as the other, it could be a sign of a burned-out bulb.


Headlights can be used in most nighttime conditions, not only by people who drive the vehicle but also people who walk along or beside the road. There are two types of headlights: low beams and high beams. Low beams are intended for use on most roads with street lighting while high beams are intended to be used on unlit undivided roads or divided highways where there is no opposing vehicular traffic.

Low beam headlights are equipped with single standard filament bulbs that produce an asymmetrical distribution of light with a maximum candlepower distribution of 700-900 Candelas while high beam headlights are equipped with double standard filament bulbs that produce a symmetrical distribution of light with a maximum candlepower distribution of 1,300 candelas. Each type has its own specific usage and the choice of which to use is based on the conditions of the road