White Balance in Digital Photography
Introduction to White balance in Digital Photography and Videography
Many photographers avoid using the White Balance (WB) setting in their camera simply because they think the camera can take care of it or, if necessary, they can make the colour adjustment later in post processing. This can be true but there are certain variables which can cause an undesirable colour cast in our images and sometimes post processing will not help us a lot (especially if you shoot in Jpeg format).
In this series of articles I am going to explain a basic definition of White Balance in Photography and Videography, take a look at White Balance presets and give you some tips on when you should consider using a custom White Balance in Photography or Videography.
What is White Balance?
Let’s look up the definition of White Balance in Photography in Wikipedia:
“In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly neutral colors – correctly; hence, the general method is sometimes called gray balance, neutral balance, or white balance. Color balance changes the overall mixture of colors in an image and is used for color correction; generalized versions of color balance are used to get colors other than neutrals to also appear correct or pleasing.
Image data acquired by sensors – either film or electronic image sensors – must be transformed from the acquired values to new values that are appropriate for color reproduction or display. Several aspects of the acquisition and display process make such color correction essential – including the fact that the acquisition sensors do not match the sensors in the human eye, that the properties of the display medium must be accounted for, and that the ambient viewing conditions of the acquisition differ from the display viewing conditions.
The color balance operations in popular image editing applications usually operate directly on the red, green, and blue channel pixel values, without respect to any color sensing or reproduction model.”
Does it sound complicated?
In technical aspects, White Balance or colour balance is very complicated, but as a photographer or videographer you just need to know how to see the colour cast and how to fix the problem.
What is “Colour Cast”?
You’ve probably noticed when checking and reviewing your digital photos that at times images can have an orange, blue, yellow etc cast to them, although to our eyes the scene looked quite normal. Pronounced and heavy colours such as Yellow, Blue, Orange is called “Colour Cast”.
What causes Colour Cast?
The reason for colour cast is that different sources of light have a different ‘colour’ (or temperature). These differences in colour/ temperature range from the very cool light of a blue sky through to the very warm light of a candle.
We don’t generally notice these differences because our eyes adjust automatically for it. Unless the temperature of the light is very extreme a white sheet of paper will generally look white to us. A digital camera, however, will faithfully and accurately record the predominant (and usually invisible to us) colour temperature. This is why digital cameras have different settings for White Balance.
In next part of this series I am going to discuss the different settings for White Balance starting from Auto White balance to some presets and I will finish up by explaining Custom White Balance.
Check our Photoshop Layers and Mask workshop on September 17 and 18. This is a full hands on class on Photoshop and the power of Layers and Masks.
Ted and the Omnilargess team