How often do we find ourselves watching videos where the talent (Or person on camera) is one color that looks correct, but then the sky is either insanely blue or the walls look like they’re pure red? Kelvin, that’s why.
One of the core principles of video production is knowing our color temperatures, because if we don’t we stand to look foolish.
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 (Incandescent) register in at 3200k, a bit cooler than let’s say it’s nearby neighbor the candlestick coming in at a low 1900k. They’re obviously the most common among the practical lights around us each day and in our homes.
The dreaded fluorescent lights that we all know and love! It’s even hilarious that one of the bulbs in the photo (Right side) is even the wrong color temperature compared to its companions. These are the lights in your workspace/warehouse etc. They’re older, and more than likely losing their jobs to LED lights, however it’s still a standard measurement on the Kelvin scale because these lights come in at 4200k (Whereas LED lighting is either single temperature or bi-color temperature which we’ll get into later).
Daylight (Bulbs and/or just the big blue sky above you)
Now we of course go to the big bulb in the sky for our final core light source, daylight comes in at a cool 5600k. Although the other lights remain their color temperature throughout the day, daylight can ~shift~ in theory. If the sun goes down, you’re still in daylight however the shade and cloudy weather have they’re own color temperatures at that point shifting well past 6000k.
So What Does This All Mean?
Color temperature is extremely important when we decide to think about our video production/lighting setups. Mixing color temperatures can add some cool effects … sometimes … but let’s leave that up to professional Director of Photographers and keep things simple for newcomers.
When shooting video, we want to try and match our key light/fill lights with the ambient light around us. So for example, if I’m out on the street filming on a beautiful sunny day, I’d be an idiot to key light with a incandescent bulb with a 3200k temperature.
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 5600k daylight would soon wash to blue and the image is ruined (Unless it’s on purpose of course).
So when purchasing LED panel lighting which has become extremely popular due to their low costs, be aware if they’re a single color temperature light or bi-color, meaning that they can be adjusted from ~3200k–5600k~ to match your main light sources in your surroundings.