headlights

Headlights are not all the same. Image via Adobe Stock

From halogen to lasers: Dazzling headlight options to choose from

The development of cars’ headlights has kept pace with automotive technology, and motorists are now seeing better and further than ever before.

headlights

Headlights are not all the same. Image via Adobe Stock

The only time you think about headlights is when you are in the middle of nowhere, otherwise known as the N3 between Villiers and Warden in the Free State, and one or both lights vanish.

It is then that you understand what is meant by “pitch black”. If your night vision is up to the task, you switch on your hazards and drive on — hoping that the last signpost said Villiers 10 and not 100.

The history of headlights

The history of headlights matches that of the development of cars. With the advent of modern lights, and the ability of some vehicles to see around corners, things have changed.

There’s no need any more to switch off the radio when you want your high beams to perform (anyone with grey hair and a 60s Beetle will nod in agreement).

Halogen headlights

The most common headlight in use is the halogen bulb. Electricity pulses through a tungsten element in a glass capsule filled with halogen gas, and there you have it — light, although it may have a slightly yellow tinge.

Their main shortcoming is that energy is lost as heat. Trying to cut through the stygian darkness of the N3 should provide a clear view for about 100m.

Xenon

Move on to Xenon, also known as high-intensity discharge lights. The Xenon light works by creating a high voltage area between two electrodes with the remaining space filled with Xenon gas.

Slow to heat up, they provide a light that at a peak, well, leaves halogen bulbs in the dark. The light they emit is bluish-white, and because you can see ahead for between 200m and 250m, you will spot that suicidal meerkat long before it becomes a radiator ornament.

Light-emitting diodes

Light-emitting diodes are a significant advance. They are simple, need virtually no warm-up time, are easy on your electrical system and produce a light that is thrown about 300m.

Matrix headlights

Matrix lights are lots of small LEDs gathered together to make a headlight. Supertech options, they are definite upmarket offerings that are usually “twinned” with a camera in a car’s rear-view mirror. When the system detects a vehicle, it shuts off individual LEDs, so other drivers are not dazzled.

Laser headlights

In the Bond stakes are the laser lights fitted standard to the BMW i8, Audi R8 LMX, and the new BMW 7 Series, the first production vehicles to carry them.

To quote the guy at Osram: “Laser diodes are particularly impressive due to their small size. One laser diode generates an almost punctiform luminous flux on a few thousandths of a millimetre.”

Ya, well, no fine. Translated, this means headlights can be much smaller without compromising on light intensity. In the words of BMW, the lights can be 1 000 times brighter than LEDs.

They work by having three blue lasers firing beams onto a set of mirrors. The mirrors focus the energy into a lens filled with yellow phosphorous that emits an intense white light (the good thing is that when somebody with these lights helps you out by directing lights on you while you fix a flat, you get a free suntan).

As is usual in things motoring, the simpler the light, the lower the price. The laser light fitted as an optional accessory in 2014 (an early laser) was offered for retrofitting to a BMW at just £7 995 (that is about R172,276 in today’s money).