What is White Balance?
Lighting sources, either it is natural or artificial do come in different types. Natural light from the sun differs according to the time of day and whether the sky is fair or cloudy. Artificial light differs between incandescent bulb and a fluorescent tube. Human eyes are so powerful that no matter what the lighting condition is, a white paper appears white.
However, cameras are not as flexible as our eyesight therefore WHITE BALANCE feature is introduced to do COLOUR CORRECTION. Although Auto White Balance may do the job, sometimes cameras do struggle in certain lighting conditions and create blue, green or orange colour cast. Understanding digital white balance can help you avoid these colour casts, thereby improving your photos under a wider range of lighting conditions.
Colour temperature & Preset modes
Differences in light are expressed in colour temperature, which is measured in kelvins (K) unit. Camera manufacturers have given more than 5 pre-customised white balance settings which are shown below.
The description and symbol for the above white balances are just rough estimation for the actual lighting they work best under. So, using the white balances in each lighting condition may produce the right colour for your images.
Provided that you know the lighting condition is, using white balance with higher/lower colour temperature can produce warmer/cooler images. However, using too high/too low colour temperature may produce extreme orangish/blueish colour and it is undesirable.
Auto White Balance (AWB)
In AWB, the camera will detect the ambient lighting and automatically adjust the camera to reproduce colours in a way that closely resembles what we see. AWB works for most of the time unless you want your images to be warmer or cooler.
Custom White Balance (Canon) / Preset Manual (Nikon)
This setting allows you to use the correct white balance with no worries. All you need to have is a middle gray/white subject (a card or a paper)
1. Set the white balance to custom white balance/preset manual.
2. Position the middle gray/white subject (a card or a paper) in the same lighting as your subject.
3. Take an image of the card/paper. Make sure you apply exposure compensation correctly. Since the card/paper might be hard to focus, use manual focus instead.
4. Press the menu button and look for Custom WB option. It wants to use an image as a reference. So, you select the card/paper image that you just captured.
5. That’s it. Now, you can take photos of your subject!
Using this setting is even more manual. You adjust the COLOUR TEMPERATURE so you don’t need a gray/white card. In order to use this settings effectively, you may need to remember the colour temperature values for daylight, cloudy and the others.
Lets say, you use daylight setting (5200 K) and the image is somehow dull and you wish to warm the image. So, you decide to use cloudy setting (6000 K). However, the image is too orangish and it doesn’t look good. Therefore, using the Kelvin setting and set the white balance to 5500 K may produce a nice warm image.
How to creatively use white balance
For most of the time, the Auto setting will produce the correct white balance. But sometimes you may want to change the white balance setting for creative effect. There are two ways to do this.
First, you can manipulate the colour contained in the light itself. For an example, fluorescent light have low colour temperature. If you use fluorescent white balance setting, the resulting image will turn white, as your eyes see. If you use a setting such as Daylight (which has higher colour temperature), then the resulting image will have an orangish tone, which somehow “warms up” the image.
The second technique is to add a colouration that is not actually there. For an example, if you want to produce an ‘autumn mood’ in the photo, you should use a white balance with higher colour temperature than the ambient light. On the other hand, if you want to add a blue tone to the scene in order to create a sense of coolness, you should use a white balance with lower colour temperature than the ambient light.
My impression of autumn is that it is slightly orange-reddish, although in reality the sunlight is not that strong to produce that kind of colour. Expectation can be met by using a white balance with higher colour temperature such as Shade or Cloudy. This will add a pleasing orange hue to the image. Now, you can say he is an autumn guy!
Sunset looks more impressive if the orange-reddish tone is emphasised. Using Cloudy white balance over Daylight brings out this tone and the sunset appears warmer.
An orangish glow emerges at the bottom of the bridge after the sunset. This is somehow attractive, but the image looks more appealing if the image is cooled down by using a white balance with lower colour temperature. People call it blue hour, therefore using Fluorescent or Tungsten white balance may boost the blue tone in the image.
Post-processing Vs White balance
Most post-processing software offer white balance correction and the popular software are Photoshop and Lightroom. Sometimes, you get a very weird colour cast and post-processing is the only way to save your precious images.
Performing white balance correction is much easier in these software as you only need to adjust the colour temperature and green-magenta slider until you get the desired colour. You may also use the white balance selector and choose a neutral reference in the image to get the correct white balance thus eliminating colour cast.
Why post-processing? Because you can see the changes for every adjustment you make to the white balance. Sometimes, the moment changes rapidly and you don’t have much time to guess the right colour temperature. Other than that, cameras offer low range of colour temperature while these software offer 2,000 – 50,000 K colour temperature.
Why no post-processing? Because you don’t like it and you are already satisfied with the colour in the images. If you can get complete understanding in colour temperature, you can use the Kelvin setting effectively.
Sometimes, you get undesired blue, green and orange colour cast because you don’t apply white balance correctly. Auto White Balance can give the correct white balance as what human eyes see. However, creative white balance applications can warm or cool an image which is more appealing.
Actually, it depends on your judgement to select the degree of warmness or coolness in your images. Every people have their own perspective on the colour that an image should has. Sometimes, you are already satisfied with the colour that Auto White Balance produces.
Nevertheless, I hope you will be able to apply white balance effectively and take awesome photos. Do enjoy photography!