White Balance in Photography: A Complete Guide
The Importance of White Balance in Digital Photography
It's a common experience for digital camera users: a photograph is reviewed, and the colors appear inaccurate – skin tones are unnatural, white garments exhibit a blue cast, and the overall image is visually displeasing. White balance is the solution to this problem.
A firm grasp of camera white balance is fundamental to achieving high-quality photographs with a digital camera. Incorrect white balance can result in unusable images or, at minimum, significant time spent in post-processing attempting to correct issues that could have been addressed during capture.
What is White Balance?
Properly adjusting white balance will prevent disappointing results and reduce the need for extensive image editing. This tutorial will explain the concept of white balance.
We will also demonstrate how to adjust it directly on your camera, and explain the reasons for doing so. Finally, we will illustrate the negative consequences of improper white balance settings with illustrative examples.
Why Adjust White Balance?
Different light sources emit varying color temperatures. These temperatures are measured in Kelvin (K). For example, sunlight has a cooler temperature, while incandescent bulbs have a warmer temperature.
Your camera's white balance settings tell it what "white" should look like under a specific light source. If the camera isn't told correctly, all other colors will be off.
- Auto White Balance (AWB): The camera attempts to determine the correct white balance automatically.
- Preset Modes: Options like Daylight, Cloudy, Shade, Tungsten, and Fluorescent.
- Custom White Balance: Allows you to manually set the white balance using a white or gray card.
Choosing the appropriate setting ensures accurate color rendition in your photographs. Using preset modes or custom settings provides more control than relying on AWB.
Incorrect white balance can lead to color casts, making images appear unrealistic or unprofessional. Understanding and mastering white balance is a crucial step towards improving your photographic skills.
Understanding White Balance in Photography
To fully grasp the significance of accurate white balancing, two key concepts must be understood. Firstly, light possesses a characteristic known as color temperature.
Color temperature is conventionally measured using the Kelvin Scale, with typical ambient light ranging from approximately 1,000K to 10,000K. Sources like candlelight, incandescent bulbs, and early morning sunlight emit a warm, reddish-yellow hue and register lower on the scale (around 1,000-3,000K). Conversely, midday sunlight and camera flashes produce a relatively neutral, whitish light (approximately 4,000-5,000K).
As the color temperature ascends beyond 5,000K, light exhibits a cooler tone. Many fluorescent lights found in offices, and the high-intensity lamps used in jewelry and art displays, fall within this range. (Further details regarding the science behind color temperature can be found here.)
The Human Visual System and Color Adaptation
Interestingly, while we perceive variations in color temperature – easily distinguishing between the warmth of candlelight and the coolness of a hospital lamp – our brains excel at compensating for these differences. Human vision is remarkably adaptable, and our eyes and visual processing centers continuously correct our perception.
This innate correction allows us to accurately identify white under diverse lighting conditions. Whether observing a white shirt in an office, bathed in sunset rays, or illuminated by candlelight, our brains calibrate to the scene, ensuring the shirt consistently appears white.
How Cameras Differ
Unlike the human eye, digital cameras lack this automatic color correction capability. They rely on algorithms to estimate neutral tones (whites, grays, and blacks) within an image and then adjust the overall color balance accordingly. This is a complex engineering challenge.
Technological advancements have improved the ability of modern cameras to detect appropriate white and neutral tones. However, cameras often fall short of perfect accuracy.
The automatic white balance features can create a false sense of security. Reviewing photos later may reveal subjects with unnatural skin tones – appearing overly flushed or exhibiting a bluish cast.
Automatic White Balance: A Helpful Tool, But Not Infallible
Consider the automatic white balance features in your camera analogous to grammar checking tools in word processors. A word processor doesn't truly comprehend the nuances of language, just as a camera's processor doesn't fully understand light.
Similar to how a grammar checker makes an educated guess ("This appears to be a comma splice...") and flags a potential error, the camera estimates the lighting conditions and adjusts color tones accordingly. Approach the camera’s automatic white balancing with the same cautious attitude you apply to grammar checker suggestions.
Understanding and Mastering White Balance
Many digital cameras, including those found in smartphones, offer manual white balance adjustments. Simpler cameras may limit options to settings like Automatic, Indoors, or Outdoors. However, more advanced cameras provide a wider range of pre-calibrated lighting conditions and the ability to establish a custom white balance based on the existing light.
Applying White Balance Settings
For demonstration, we’ll utilize a Nikon D3100 DSLR, though the principles apply to any camera with adjustable white balance features. It’s important to note that white balance settings are typically inaccessible when the camera is in full-auto mode.
To experiment with white balance, switch to shooting modes such as Aperture Priority, Shutter Priority, or Manual. This allows access to the camera’s settings, including the White Balance Menu.
Within the menu, you can select preset options tailored to different shooting scenarios. Consider whether you are shooting indoors with incandescent lights, in direct sunlight, or in shaded conditions.
Demonstrating White Balance Effects
Preset options can be used to illustrate the impact of incorrect white balance. We’ve created a scene featuring a white card and a photography assistant, positioned against a garden backdrop. This setup serves as a reference point to showcase how white balance shifts affect overall color accuracy.
First, let’s examine a photo captured with the camera set to automatic white balance. Given the substantial white reference area, the camera should ideally achieve accurate results:
Despite the large white area, the automatic white balance isn’t entirely precise. The image exhibits a slightly warm tone, with the white card appearing yellowish. Gray and cream tones also lean towards yellow, and the foliage displays a greenish-yellow cast.
Illustrating Incorrect Settings
Before correcting the minor imbalance, let's observe the results of a severely incorrect white balance setting. We’ll manually set an inappropriate setting to simulate common errors that occur when shooting conditions change or flash settings are adjusted.
Here’s the same scene, but with the white balance set to incandescent – a much warmer temperature than the indirect sunlight present:
A significant white balance error results in images with pronounced yellow/red or blue/green tints.
Achieving Accurate White Balance: Custom Settings
While presets can help, they rarely deliver perfect results. The most reliable method for accurate white balance is to set a custom white balance tailored to the specific shooting conditions.
On the D3100, the White Balance Menu includes an option for a custom white balance. This requires capturing a full-frame image of a white or 18% gray card.
If a dedicated card isn’t available, a piece of bright white card stock serves as a suitable substitute in many cases.
Here’s the resulting photo after zooming in on the white card, capturing a reference image, and reframing the shot:
This photo most accurately represents the colors of the actual scene. The facemask appears cream-colored, the body striping is grayish-white, the white card is truly white, and the wood bench exhibits a bluish-black weathering instead of a greenish hue.
By calibrating the camera directly against a full-frame white card, we achieved a perfectly neutral color balance.
Situations Where Perfect White Balance Isn't Ideal
This leads us to a crucial consideration. While the preceding image demonstrates a perfectly neutral color balance, this outcome isn't always desirable. For instance, a previous Sony digital camera I owned consistently produced images with a slightly warm cast, even after white balance adjustments.
I recognized this wasn't perfectly neutral color rendition, but I appreciated the resulting warmth – portraits appeared flattering, and landscapes and flowers felt inviting.
The purpose of this guide is to educate you on the impact of white balance and how to control it. Specifically, it aims to prevent you from encountering strangely tinted photos and struggling to diagnose and correct the issue.
Understanding color temperature and how to adjust white balance empowers you to manipulate it creatively. You aren't obligated to strive for perfect neutrality in every photograph.
Leverage your newfound ability to warm or cool images as you prefer. Many scenarios, such as capturing the cozy atmosphere of candlelight, benefit from avoiding a completely neutral balance.
You might choose to reduce excessive warmth, yet still retain the subtle yellows and reds characteristic of low-temperature light sources like candles.
Do you have a helpful photography tip to contribute? Perhaps a streamlined white balance workflow that could benefit others? Share your insights by participating in the discussion below.