Understanding White Balance and its Limitations

Many people believe incorrectly that white balance produces accurate color. That’s not true.

Then why do we need it? Read on, because that’s what this article is all about.

What is White Balance?

I’ll try to explain in simple lay person’s terms:

White balancing is the process of eliminating any tint to your image.

When you white balance an image correctly, the whites, grays, blacks should be neutral. There shouldn’t be any additional hues in them.

Guess what else is neutral? Greens, reds, blues, oranges, and every other color. They are also neutral without any additional hues in them.

However – a big HOWEVER – just because there are no tints to your colors doesn’t mean the colors are accurate to begin with. All white balancing guarantees is the red or green or blue or whatever you see is the way the camera intended it to be. That’s it.

Understanding the limitations of white balance

Here’s a quick video that explains the limitations of white balance:

Corrections:

  • Towards the end I say ‘white balanced to 5600K’, but it’s 5400K as written on the text in the video

 

How to white balance

Each camera does it slightly differently, but the general steps are as follows:

  • Hold up a neutral card (white or grey, doesn’t matter) that has been printed according to strict standards.
  • Make sure the card is held in the exact lighting you’re going to shoot in. If your subject is in the sun but you are in the shade, there’s no point holding it right in front of you. Your subject must hold it up in the lighting he/she is shot in. Same applies to artifcial or indoor lighting.
  • Use the custom white balancing setting in your camera to find the white balance. Set the white balance to this value.
  • Some cameras allow you fine control in increments of 100K, as shown in the video. Some don’t display the Kelvin value, like the Canon 550D.
  • White balance is written in K (Kelvin), which is color temperature. 3200K is warm, 7000K is cool blue and so on.
  • If you match white balance accurately, the tint (warm, cool blue, etc.) will be eliminated. E.g., a tungsten light looks yellow. In the video, I’ve shot a scene with a 3200K tungsten fresnel. If I white balance my camera to 3200K, the colors will be neutral. However, if set it to 5600K, it will be warmer (orange tint).
  • You can use this feature to create a look in your image. Gordon Willis created an orange feel to The Godfather using lighting. Today, you can also use white balance to get something similar. White balance is a creative tool to give your image an overall tint, but it can’t control colors individually.
  • Most of the time, though, you’re trying to balance the white to your lighting so you have neutral colors – in other words, colors as your camera intends them to be seen.
  • Remember, a variation in 100-200K is acceptable. On a 2600-9900K scale, that’s an error of about 1%. Most humans won’t be able to tell the difference without a side by side comparison. So don’t get anal about perfectly accurate white balance.

 

Which white balance preset to use?

For the most accurate control and professional results, there’s only one answer: Custom white balance.

You must go through the trouble of holding up your card, white balancing in camera and locking on to that – for every change in setup. This way your images will be somewhat consistent to each other.

Even if you use artificial lighting, you must custom white balance. Why? Here are some reasons:

  • Daylight changes color temperature due to various factors – clouds, foliage, sky color, position, shade and intensity of the sun, geography, etc.
  • Tungsten halogen lamps can vary from 2600-3500K.
  • HMI lights are rated at 5600K, but can be 6000K or higher sometimes.
  • LED lights, even the bi-color ones, are not always calibrated accurately to the exact color temperature.

When you live and operate in a world that can’t guarantee lights will conform to the presets in your camera, custom white balance is the only way to stay consistent.

So how do you get accurate colors?

The only way to get accurate colors with a single camera or multi-camera is through grading. You can grade in camera or in post production. Since this a whole new can of worms (the ugliest kind), I’ll leave that for a later article.

But as I said in the video: White balancing is just the first step to accurate color.

3 replies on “Understanding White Balance and its Limitations”

  1. Hi Sareesh,

    What are the camera settings used to shoot a movie in India, like the aspect ratio, the formats etc. Do they use any color presets to get the desired look as we do for photography in canon dslr or nikon dslr or do they do it in Color grading.

    Regards,
    Kiran

  2. Sorry but this is not totally accurate. A 20 % grey card is what is needed. Why? Grey by definition is exactly equal parts red green and blue. So having a grey card for each camera in each situation will match colors. Fancy color cards and devices are just not need they are profit machines. A great deal of what you say is fine but this aspect is not correctly presented.

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