White Balance in Digital Photography
In previous articles, I discussed the Exposure. Simply, the Exposure is about the brightness and contrast of a photo. However, the colour rendition of a photo is set by White Balance. Therefore, understanding white balance is as important as exposure in digital imaging.
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, however, there are certain variables which can cause an undesirable colour cast in our images which 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.”
What is a “Colour Cast”?
You’ve probably noticed that at times images can have an orange, blue, yellow etc. cast to them. Pronounced and heavy colours such as Yellow, Blue or Orange is called “Colour Cast”.
Below is a sample of the colour cast.
Sample of the 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.
However, we don’t generally notice these differences because our brains 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.
That is all for now. Stay tuned for my next photography Tips in White Balance. We love to hear from you. Let us know if you have any questions, feel free to send us your questions and we will be more than happy to answer them. Follow us on Facebook, Instagram and Twitter for more Free Tutorials and Tips.
Ted and the Omnilargess Team