Although white balance is one of the key concepts in photography, many photographers fail to take it into consideration when they tune up their camera settings for a special shot.

Big mistake, I must say, because the proper use of white balance can work wonders for most photographs! It’s one of the important photography tips you have to bear in mind. Think of all the shots that were ruined because you failed to select the correct white balance, or the number of average shots that could have been much more impressive if you had taken white balance into account.

what is White balance blue color cast

This picture depicts how proper white balance selection makes a marked difference in the overall look of the photo.

What is white balance?

White balance is the correction of the incorrect color casts that result in a photographic misrepresentation of neutral shades, particularly white.

Why is it necessary to set white balance?

The selection of the correct white balance is necessary in order to keep the colors as realistic and accurate as possible.

The human eye adapts well to the perception of white, regardless of lighting conditions. Cameras, on the other hand, do not. For this reason, in tricky lighting situations, cameras often misinterpret neutral colors, such as white or gray. When this happens, the image will have a particular color cast to it, ranging from extreme red to extreme blue. Photos with a reddish color cast are often referred to as “warm” while those with a bluish color cast are said to be “cool.”

Understanding the underlying concepts of white balance selection can help you get images with accurate color reproduction and without annoying colors casts.

what is White balance-flowerA photo of flowers with blue color cast.

 

White balance pic 3Color cast removed through proper white balance selection. Color depiction is now accurate.

Understanding color temperature

White light is not a single color but rather a mixture of several colors (violet, indigo, blue, green, yellow, orange, and red) . Pure white light is achieved through an equal distribution of all these colors, which is very rare indeed. White light often tends to have a slightly blue or a slightly red shade.

This shade of white light is frequently described on a scale referred to as “color temperature.” Color temperature is expressed in Kelvins (K). Values below 5000 K represent a reddish shade of white, while those above 5000 K represent a bluish shade of white. 5000 K itself can be considered neutral white light. This is further depicted in the graph below.

At 5000 K, the relative intensity of the all the wavelengths (from 400–800 nanometers) is fairly equal. At 9000 K, the intensity of the shorter wavelengths, which constitute violet and blue colors, is much higher than that of the longer wavelengths, which make up the red colors. As a result, light of a color temperature of 9000 K is quite blue in color and light at 3000 K is red-orange in color.

white balance wavelength and intensity

Now, you might be wondering why we describe a shade of color through the unit of temperature instead of the traditional unit of light wavelength. If you are familiar with physics, you might have heard the term “black body”. Black body is a hypothetical object that is capable of fully absorbing all the electromagnetic radiation that falls on it, including light. Pure black bodies do not exist, but there are objects that behave like blackbodies at high temperature.

Let’s consider the simple example of metallic iron heated to a very high temperature. As the temperature of iron rises, it first becomes red in color and later it becomes white. The color of white also undergoes changes at different temperatures. Hence, in our photographic color temperature scale, we don’t actually describe the color in relation to temperature itself; rather we compare the color of any kind of white light to the shade of white that a black body would emit if it was heated at that particular temperature.

The importance of using color temperature lies in the fact that various light sources and lighting conditions closely resemble the various shades of white color emitted by black bodies at different temperatures.

The following table shows some light sources and lighting conditions with their corresponding color temperatures. The values of color temperatures are common averages and are subject to variation.

Light source or Lighting condition Color temperature
Match stick flame 1500–1700 K
Candlelight 1500–2000 K
Sunrise/Sunset 2000–4000 K
Household tungesten bulbs/Incandescent lamps 2700–3300 K
Fluorescent lamps 3500–5000 K
Daylight (Clear sky)/electronic flash 5500–6000 K
Daylight (Cloudy) 6500–7500 K
Heavily clouded sky 8000–10000 K
LCD Screen 6000–11000 K
Clear blue poleward sky 15000–27000 K

How to use white balance presets

Most of the modern cameras do not require you to fiddle with the color temperature manually and are equipped with a number of white balance presets. These presets cover the commonly encountered light sources and lighting conditions. The ones included in most cameras, in order of increasing color temperature, are Tungsten, Fluorescent, Daylight, Flash, Cloudy, and Shade. Some cameras also allow you to further control the extent of these presets (e.g., -5 to +5 or so).

The following table contains a list of white balance presets with an explanation of when to use them.

WB Presets Use
Auto When this preset is selected, the camera automatically determines the best white balance for the photos. Although it is fairly good in most situations, it fails to give a correct color representation in many photos. Furthermore, it is always recommended to use manual white balance whenever possible, because in most cameras, the auto mode does not allow the white balance to go to any extremes in order to keep the tone an average for most situations.
Shade The light in shady environments generally has a blue color cast. This preset aims to remove that color cast.
Cloudy This preset, as the name indicates, warms the colors sufficiently to remove the deep blue color cast produced under an overcast sky. The photos produced have a warm, deep look.
Flash This preset aims to remove the blue color cast produced by most camera and electronic flashes.
Daylight This preset is used when shooting in daylight. It removes the cool color casts that can sometimes form in such conditions and creates a warm look in the photos.
Fluorescent This preset is used when the environment is lit by fluorescent lighting. Fluorescent light generally creates a blue color cast. This preset serves to neutralize the blue to produce accurate colors.
Tungsten/Incandescent This preset is for indoor use when the environment is lit by a tungsten bulb, which produces yellow light. This preset removes the yellow cast in order to keep the colors as accurate as possible.

White balance advantage to using raw format

Many DSLRs and some other high-end cameras allow you to render images in raw format. The use of raw format has a great advantage from the perspective of white balance, because it allows you to capture the photo first and apply a white balance of your choice after the photo is shot.

White balance can be changed in JPEG images through editing and post-processing. However, the results produced by raw images are much more impressive.

Auto vs. manual white balance

As mentioned earlier, manually selecting the correct white balance always has better results than auto white balance. When auto mode is selected, the tricky colors and lighting often trick the camera into selecting an incorrect white balance. For example, if the image has too much red, the camera might incorrectly create a bluish cast in the photo to counter the warmth in the photo.

The following examples show how the correct use of white balance can significantly improve your images.

Consider the following photo that I captured in overcast daylight using auto white balance. It has a slightly blue cast on it.

 white balance flower before

Here is the same flower captured after properly setting the white balance. The image now shows much more accurate and impressive colors.

white balance flower

Consider this photo captured after a rain shower. It has a slightly blue cast to it.

White balance branch before

In this case, following some post-processing and white balance tweaking, I was able to get a much better end result by warming up the photo. This shows that my original photo could have been much better out-of-the-box if I had tweaked the white balance settings correctly.

white balance branch after