LED Lightbar Colour Temperature - What Does It All Mean?
If you're been investigating LED lighting you've probably seem mentions of colour temperature and wondered what that was all about. Seeing as the specifications for a lot of LED lights talk about colour temperatures of over 5,000K (that's 4,727°C) you'll probably be relieved to hear that colour temperature has nothing to do with how hot the light gets. It's actually all about the quality of light that's produced. All light sources work by turning energy into photons, but photons aren't all the same. Depending on the energy of the process that created them they have different energy levels of their own, and that affects what the light looks like.
Scientists work out colour temperatures by comparing light sources to black body radiation. In physics a black body is an object that absorbs all energy that hits it. It's nothing to do with its colour, because a black body will appear to be a different colour depending on what temperature it's at. A good example is charcoal on a grill. The colour temperature of a light, like an LED, is the temperature of a black body that would look the same colour.
That's what the scientists say, at least. The lighting industry decided that wasn't confusing enough, so they decided to change things round a bit. Lights with a lower colour temperature tend to have a yellowish - maybe even orange or red - colour. Lights with a higher temperature are white, and if you go higher still they turn blue. Yellowish light has a nice warm feel to it though, so a low colour temperature is described as warm light. Because white and blue are thought of as cold colours really high colour temperatures are described as cold. This is where it helps to remember that colour temperature doesn't have a lot to do with actual temperature.
So what does all this mean when you're buying lights? Basically it means you have to work out what the light is for. Are you after an awning light to use when you're camping out? You'll want that to be bright enough to see what you're doing, but "warm" enough to create a nice relaxing atmosphere. A colour temperature of about 2,700K is ideal here. That's the same as a normal incandescent light bulb, which is the standard everyone aims for when choosing lights at home.
If you're looking for a lightbar or work light things are different, though. Here you want a clear, bright light that lets you see exactly what you're looking at. Because of the way our eyes have evolved we see best in daylight, which means a colour temperature of around 5,500K. If you want a lightbar that will show the ground ahead in clear detail you should choose a much "cooler" light.
Colour temperature can be a pretty confusing subject, and normally we'd say leave it to the scientists. It's an important factor when you're choosing LED lights, though. Hopefully this quick guide has given you the information you need to get it right.