What is Color Temperature and Why Should You Care?
MARCH 28TH, 2023
Kelvin
How often do we find ourselves watching videos where the talent(person on camera) is toned naturally, but the sky is either TOO blue or the walls look like they’re orange or red? Kelvin, that’s why.
One of the core principles of video production is knowing our color temperatures because if we don’t, our image will start to fall apart.
Kelvin (K) is the base unit of temperature in the System of Units, and it’s how we light scenes. Let’s start with the three core temperatures we find around us each day, then we’ll dive into what happens if we try to mix and match these color temperatures.
Light Bulbs and Candles
Light bulbs or incandescent light registers around 3200k, a bit cooler than it’s predecessor, the candle, coming in around a low 1900k. They’re the most common among practical lights used each day and in our homes.
Fluorescent Bulbs
Ah yes, the dreaded fluorescent light that we all know and love! These are the lights in most offices, workspaces and warehouses. They’re older, more expensive and slowly being phased out by LED lights, however they’re still a standard light source and measurement on the Kelvin scale, coming in at 4200k(LED lighting is either single temperature or bi-color temperature, which we’ll get into later).
Daylight(Light Bulbs or the Sun)
Now we go to the big bulb in the sky for our final core light source, the Sun. Daylight comes in at a cool 5600k. Light bulbs stay the same color temperature throughout the day whereas the Sun’s temperature can ~shift~. For example, if the sun goes down, you’re still in daylight however the shade and cloudy weather have their own color temperatures, shifting it well past 6000k. Morning sunlight, peak daylight and evening light are all different color temperatures, ranging from cooler to warmer. It’s important to keep this in mind when considering filming outside and away from controlled light.
What Does This All Mean?
Color temperature is extremely important when we decide to think about our production and lighting setups. Mixing color temperatures can add some cool effects…sometimes…but let’s leave that up to professional DP’s and keep things simple.
When shooting video, we want to try and match our key light and fill lights with the ambient light around us. For example, if I’m out on the street filming on a beautiful sunny day, I wouldn’t want to key light with a incandescent bulb at 3200k. We’d want to match the Sun and find a daylight balanced light source.
If I were to key my subject with an incandescent source and match my camera to that color temperature, the outside world around my subject would look like we were underwater. Everything around my source that was being hit with 3200k would wash to blue and the image is ruined(unless you’re creating this look intentionally).
So when purchasing LED lighting, which has become extremely popular due to their low costs, research whether they’re a single color temperature light or bi-color, meaning that they can be adjusted from 3200k to 5600k(often a much wider range) to match the main light source of your surroundings.
Final Takeaways..
Just like every other aspect of filmmaking, rules can be bent, but generally speaking, making sure your subject is lit and exposed properly is the most important. There’s always room for experimentation with lights, that’s the beauty of it. With the integration of LED lighting into the industry, it’s made our job a lot easier to get it right. With bi-color and full RGB gamma lighting, the possibilities are endless, so have fun with it!
