When we consider which type of headlight bulb to get for better lighting it is really important to understand whether you need a projector or reflector headlight. Normally a projector headlight would accommodate an H11, 9005 or 9012 single beam halogen light bulb.
If you are interested to make to headlights brighter, you may want to opt for an LED light bulb options to replace the halogen counterpart.
Problem is there are hundreds of different LED light bulbs and some of them will not fit into the headlight housing or do not produce a good beam pattern. To make things even worse, some of them are not even as bright as the original halogen bulb.
A projector does both beams, low and high, even though it uses a single filament light bulb. Inside a projector there is a shutter that opens and closes to show you all of the light output or only half. So even if you have a basic single filament light bulb you can still get the dual beam out of a projector headlight.
This is not the case with the reflector analog. Projectors can make one or two beams depending on the design while reflectors are always one beam. If you want reflector to do both hight and low beam you have to use a different type of a light bulb.
Nowadays, a lot of cars can come with a projector and reflector type of headlights on the same vehicle. For example, you can replace reflector headlights with a projector kit of the same shape. It is a pretty common upgrade because some people like the way the projector looks. Theoretically, it also provides a better beam pattern.
Reflectors are pretty simple – a bulb illuminates the chrome area inside, light source bounces off the shiny surface that creates a beam pattern. Generally, it is fairly inefficient and not very focused. At least, not as focused as compared to the projector. The interesting thing about the projector headlights is that they sometimes incorporate the benefits of both technologies.
Opposite to a very large horizontal layout found in the reflector, the projector has a very small bowl with the light bulb sitting backward. The light from the bulb is captured inside this small bowl and gets focused through the lens. The same principle is leveraged when using the magnifying glass in the sun to start a fire except for the fact the desired effect with the lens is to create a razor-sharp beam pattern.
There is one big characteristic of the different types of projector lenses dividing them into a single beam and dual beam with the latter one having a solenoid and some wiring coming out. If you give this connector 12 volts the solenoid will be activated inside the projector to lower the cut-off shield. In low beam position, not energized, the shield is upright and creates a sharp cut-off horizontal line.
When switching from low to high beam the solenoid is energized and the shield pulls down opening up the projector lens for 100 percent. In the dual beam projector, this creates high and low beams. In a single beam projector, there is simply one static projector for low beam and either another projector or a reflector for high beam. Some cars might use all three styles.
Let us sum up the differences between the reflector and projector headlights. Normally, reflector headlights will use halogen bulbs but there are certain circumstances with a vehicle coming off the factory with a reflector with HID. Same goes for projectors. It is a 50-50 situation. A lot of factory projector headlights come with a halogen light bulb but a lot of times they have LED or HID. Sometimes you can convert a reflector headlight to LED or HID with just different light bulbs. And sometimes you can do the same thing with the projector. Generally speaking, you are guaranteed an increase in light output if you convert your projector halogen bulb to HID. If you stick with LED the odds are not that good as more and more products are coming to the market which are suitable applications for an LED bulb in a projector. But if you already have projector headlights and you want to make them brighter your best bet is an HID conversion kit.