At the most basic, you’ve achieved good white balance when the camera settings and the lighting conditions align in that magical way that colors in your video look great – or at least as good as possible. And probably more than anything else, good white balance is about skin tones looking natural.
The Goals of Good White Balance, part I
The three goals of good white balance are: 1) the final white balance should look appropriate for the setting and context of the shot, 2) the final white balance should be consistent unless the setting and context changes, and 3) the white balance coming out of the camera gives you something you can easily work with in editing to achieve goals 1 and 2. This will al make more sense after we cover some important background information.
Not All White Light Is Equal
What our eyes and brain interpret as white light is a spectrum representing a range of different colors. On one side of this range is warm orangish light (like candlelight) and on the other side is cool blueish light (like heavy shade.) Daylight, which refers to the color of noonday sunlight on a clear day, is considered the reference point in the middle.
The color of light is referred to as its color temperature, and this temperature is measured in degrees Kelvin. Daylight sits at about 5200K. Warmer light has a lower temperature, with candlelight coming in at about 1500K. Cooler light has a higher temperature with heavy shade measuring about 7000K.
If you were to wear a clean white t-shirt in that warm candlelight mentioned above, it would reflect that light and appear slightly orangish. If you walked into the noonday sun it would appear a more neutral white, and when you entered heavy shade it would appear more blueish. Your brain would accept this and contextualize it, because it agrees with what you have grown to expect.
The Goals of Good White Balance, part II
The first goal of your white balance adjustment isn’t that the clean white t-shirt always appears pure white. The first goal is that the pure white t-shirt appears the way your brain expects it to in the context and setting of the shot – a bit orangish by candlelight and a bit blueish in the shade.
The second goal of your white balance is that the t-shirt appears a consistent temperature of white unless the setting and context has changes. If you are combining multiple shots, all in the same setting, the t-shirt should appear the same in each. Close up or long shot, high angle or low – the t-shirt should appear the same color in that candlelight setting.
What Factors Affect White Balance?
White balance is affected by several factors: a) the color of the ambient light present in the scene, b) the color of the additional light you add to the scene, c) any reflective surfaces that may bounce light onto your subjects, and d) the settings of your camera.
It’s pretty easy to understand factors a, b and d, but easy to overlook factor c.
Let’s say you’re wearing your clean white t-shirt outdoors in the noonday sun, and standing next to a little pink house. That house is a reflective surface (factor c) and goal 1 says your white t-shirt should probably be a little on the pink side.
What About Shooting With Auto White Balance?
When you use auto white balance the camera looks at part of the scene, averages and analyzes the color, and estimates the correct white balance. It can be pretty good – maybe a little too warm or a little too cool, but pretty close.
If the ambient or the additional light changes, or if you reframe the shot, the camera will re-average and re-analyze the scene and estimate a new setting. The problem comes in when one shot is a little too warm and the next is a little too cool and the setting and context is still the same. The subject is still wearing the white t-shirt in the shade and now you have two shots with different white balance.
The Goals of Good White Balance, part III
If you remember, we said the third goal is the white balance coming out of the camera should give you something you can easily work with in editing.
So shooting with auto white balance can work if you are in a controlled setting with consistent lighting and shooting one or more shots without reframing the image.
But if you are working with changing light, or you are reframing the shot you need to manually set the white balance for the lighting conditions and you’ll be fine.
Can You Fix Bad White Balance?
Even though it is usually possible to adjust the white balance in post-production it is always helpful to get it as close as possible when you are shooting. Depending on which editing software you use, your white balance adjustments may be limited or may require manual workarounds.
More expensive editing software, like Davinci Resolve and Final Cut Pro, typically includes specific functionality to adjust white balance. Multipurpose screen capture and editing software often require that manual workaround.
How Do You Set White Balance?
I’ll cover setting white balance on cameras, phones, and webcams in three future articles.