White balance is an important creative tool for photographers. Without getting too technical, white balance is a process which determines how color is interpreted in a digital photograph, and is typically used to remove undesired color casts from images. Getting the “right” white balance requires an understanding of how white balance works. I say “right” in quotes because white balance is often a subjective artistic choice.
What is white balance?
Visible light is actually made up of a spectrum of different colors. Although daylight in the middle of the day is more or less “neutral”—all colors of the spectrum are equally represented—other light sources transmit more light of a certain color than others. For example, fluorescent lights have a different color than sunset light. “White balancing” is a process of altering the colors of a photograph to take account for the color bias of a given light source, in an effort to make the colors in the photograph look like they were shot in neutral light. When you change your white balance, you are basically telling your camera to change the way it sees color.
But why do you need to do this? It all has to do with a subtle mismatch between the actual color of light and the way people perceive those colors.
“Fitz Roy” —Los Glaciares National Park, Argentina. Proper understanding of white balance is critical to correctly rendering spectacular sunrise colors.
How we perceive color
Okay, so light coming from the sun at the middle of the day is neutral, but as we all know the color of sunlight changes throughout the day. For example, when the sun is low on the horizon during sunrise or sunset, atmospheric particles scatter most colors except red—and as a result sunrises and sunsets are often accompanied by intense yellows, oranges, and reds. Also, the sun is not the only light source in the sky—the sky itself acts as a giant blue reflector, and anything not lit by direct sunlight, such as objects in the shade, are lit primarily by reflected blue light from the sky instead. Although we notice these colors shifts to a certain degree, we don’t perceive them fully; our brains compensate to some extent for these color shifts, doing a “mental white balance” adjustment which filters out color casts. Here’s a rather obvious example: stare at a colorful red sunset for awhile and then look behind you—for a few moments you’ll see the world as being somewhat blue, until your eyes readjust. Also, if you look at an object in open shade, you won’t perceive it with a blue color cast, even though it is lit primarily by blue light. Basically, even though the color is really there, our brains don’t necessarily see it that way.
I think it is fair to say that our perception of color is somewhat variable—to a certain extent, our brains adjust to color bias. So what? Well, film and digital cameras don’t really do the same thing unless they’re told to do so. Whereas you can “instruct” a digital camera to adjust color through software commands, you can’t do the same with film.
How film renders color
I know, this is an article about digital photography, so why am I talking about film? Some historical context is useful for understanding how white balance can be used creatively with today’s digital cameras. Besides, there might actually be a few film photographers still left in the world!
Although our color perception is variable, the chemical emulsion of film reacts to light in very specific ways. Scientists and engineers have fiddled with the chemistry of color film for decades, trying to get the colors to match human perception. But they were never able to come up with a “smart” film that could automatically adjust to changes in the color of light. Each type of film was color balanced for a specific type of light source, for example “Daylight” for outdoor shooting and “Tungsten” for studio shooting using (you guessed it) tungsten lighting.
So, what happens if you use film in the wrong kind of light? You end up with a color mismatch between the film and human perception. For example, if you use Tungsten film in daylight, everything comes out looking blue. Daylight film, which was by far the most popular among photographers, creates funky results if shot in anything other than neutral daylight. For example, if you shoot in open shade, everything comes out looking blue, for the reasons discussed above. Shoot at sunset with the same daylight film, when mostly red light is passing through the atmosphere, and you get some really intense colors (more intense than perceived by the eye). As a result, one might say that film often renders colors in an “unrealistic” way; that is, it often renders colors in a way that is different from how the human eye perceives those colors.
Photographers used to take advantage of the funky color mismatches, turning them to creative effect. A good example is a photograph of autumn color reflected in a mountain pond. Although sunlit autumn foliage reflected in the water would be rendered as the eye sees it, any shaded elements in the water would be rendered with a blue cast. The savvy photographer would juxtapose these elements in order to create an image with rich, almost painterly, color contrast—not quite “real,” but beautiful nonetheless.
“Windblown”—Acadia National Park, Maine, USA. A neutral (Daylight) white balance setting creates the blue color cast of the marsh grasses (which are in shadow and lit only by light reflecting from the blue sky above), rendering the colors in a “film-like” manner. Note that the blue cast was not apparent to the eye, but nonetheless, the blue light was really there.
The digital advantage
With digital cameras we can now easily correct color casts by casually spinning a dial to change our white balance setting—or, we can use white balance creatively, much as we did with color casts in the age of film. Basically, we finally have a “smart” capture medium capable of adjusting to variable light—or to the whims of the photographer. But how does it work? First, we need to start with a bit of science (just a little, I promise).
The key to mastering white balance is understanding color temperature, which is actually quite simple. Color temperature is basically a measurement of a color tone’s “warmth” or “coolness”, measured using what is known as the Kelvin (K) scale (named after famous scientist Lord Kelvin). Daylight from the middle of the day is considered to be “neutral,” as at that time the entire visible spectrum is lit with roughly equal amounts of all colors. Digital camera white balance also uses the Kelvin scale, with most cameras using 5200-5500K as their neutral daylight setting. Assigning a white balance with a lower color temperature makes the image look cool/blue, whereas a higher color temperature setting makes an image look warm/red—with the colors getting progressively cooler or warmer the farther away from neutral daylight you get at either end of the color temperature scale.
Cameras have a bunch of preset white balances so that you don’t have to think about numbers at all, but it is a good idea to understand the numbers even if you use the presets. Most digital cameras use something similar to the following presets and corresponding color temperatures:
Here’s a real world example of the various preset white balance settings in action. As shown by this series of images, white balance settings with a lower color temperature render colors cooler, whereas white balance settings with a higher color temperature render colors warmer.
From left to right: Tungsten, Fluorescent, Daylight/Flash, Overcast, Shade.
How white balance corrects color casts
It is important to understand that these settings are not absolute, but rather relative to the light illuminating your scene—for example, just setting your camera to “Daylight” won’t make the photo look like it was taken in neutral daylight. Not unlike with film, if you don’t match your white balance to your light, you end up with a color mismatch. If you want to ensure the color balance of your photo is closely matched to human perception, you need to select a white balance that matches your light. For example, if shooting in neutral daylight, you need to select the Daylight preset to make the colors look the way you perceive with your eyes; if you are shooting inside using fluorescent lights, you need to select the Fluorescent setting; and so on. The image below illustrates this concept. The flowers were in the shade on a clear, sunny day—and therefore they were lit primarily by light reflecting from the blue sky above . If you set your white balance to Daylight (left), then the camera does not correct for the abundance of blue light and the image is rendered with a blue color cast. To keep the colors in the image neutrally balanced, you need to choose the Shade preset (right). This will make the image warmer, removing the blue color cast.
The image above was taken in open shade on a sunny day, and therefore was lit primarily by light reflecting from the blue sky above. The version to the left shows the image taken using the Daylight preset (5500K) and shows a strong blue cast. The version to the right shows the image color-corrected using the Shade preset (7500K).
How to set white balance
Setting your white balance is easy: most cameras have a button you can press or a menu function which allows you to change the white balance. I’m not going to go into camera-by-camera specifics regarding how to set your white balance; consult your camera manual if you aren’t sure how it’s done. Basically, the process of setting white balance is easy. What is not quite as easy is determining the “correct” white balance. I list several strategies below for finding the right white balance for your scene:
Manual white balance selection using trial-and-error: You can set your white balance manually before each shot by guessing the proper white balance setting, taking the shot, and then reviewing the image on your camera’s LCD to see if you like the results. For example, if you are shooting on a cloudy day, setting your white balance to the Cloudy preset is probably a safe bet. If the white balance looks off, then guess again, and so on until you get it right. Many cameras with Live View allow you to preview white balance choices, taking much of the guess work out of the process.
Manual white balance selection using a white balance reference: This method allows you to use a “white balance card” or other reference device to set a custom white balance for each scene. Basically, the device (which is neutral in color) is placed in the same light as the subject and is used as a reference to select a white balance that will render colors in the scene as if neutrally lit. Once again, this can add time to the picture taking process, and as such is not especially conducive to field work. Also, it may not always give you an accurate rendering of the scene. For example, say you are photographing a scene lit by the warm red of sunset. Using a white balance reference in such a situation will leave you with a white balance setting that eliminates the overabundance of red light—which is why you are taking the picture at sunset in the first place! White balance devices are useful for certain studio and commercial photography applications, but are impractical or unnecessary for most other types of photography.
Always keep your white balance on the same setting: Some photographers simply set their white balance to Daylight and never look back. While this will render images in a manner similar to film, as discussed above the Daylight setting is not always appropriate, and can create unrealistic or undesired color casts.
Automatic white balance: Most digital cameras allow you to select an Auto white balance mode. In this mode, the camera tries to pick the best white balance setting for each scene. In my opinion, automatic white balance actually does a very good job, but it doesn’t always get it right, and sometimes acts inconsistently. Nonetheless, it is my preferred option.
Of course, as I discuss in more detail below, if you are shooting raw format, your in-camera white balance setting is irrelevant.
“Delicate Arch”—Arches National Park, Utah, USA. Some scenes work best if color casts are retained. The scene above was bathed in warm sunset light. Removing the color cast would have reduced the impact of the light, and rendered the scene in a way that was not perceived by the eye.
The raw advantage
One great advantage of shooting raw format is that you can change an image’s white balance when converting the raw file on your computer. This can be done in a virtually lossless fashion; that is, when changing the white balance in your raw converter, you are not degrading image quality by destroying data. This is a great advantage, because you don’t have to waste precious time optimizing white balance while in the field. Rather, you can make your white balance decisions later when processing the image, giving you more flexibility to assess various white balance options. I keep my camera set on Auto; as noted above, Auto gets it right much of the time, thereby streamlining both my shooting and raw processing workflow. Photogenic moments are often quite fleeting, and the last thing you want to be doing is fiddling with your white balance before each and every shot. Personally, I never make any effort to set my white balance before I take a photograph—although I usually have a pretty good idea of the white balance setting I will choose later during the raw conversion process.
You don’t have this same advantage if you shoot JPEGs. When shooting JPEG format, the camera’s processor converts the raw data into a finished image and then discards the raw data, so whatever white balance setting you have selected is applied to the image. If you later try to adjust the white balance of the file on the computer, you might notice some loss of image quality (typically in the form of color banding or increased digital noise), especially with significant adjustments.
Setting white balance during raw conversion
Making white balance adjustments during the raw conversion process is actually quite simple. Every raw converter has its own way of setting white balance, but they all operate in essentially the same way. I use Adobe Camera Raw for my raw conversions, so I’ll use it as a reference (Lightroom gives you the same options). Here’s the Adobe white balance palette:
Pretty simple, huh? The top slider changes the color temperature (notice how it uses those Kelvin numbers I talked about earlier). Slide it to the right (increasing the number) and the image will get warmer; slide it to the left (decreasing the number) and the image will get cooler. White balance actually uses a second variable in addition to color temperature, “tint,” which in Adobe Camera Raw can be shifted along the green-magenta axis. For the most part, digital cameras do not allow you to adjust this variable, but raw converters do.
By activating the drop-down menu, you get a number of preset options:
“As Shot” will render the scene with the in-camera selected white balance (whether selected by you or automatically by the camera). “Auto” will do its best to automatically set the appropriate white balance in a fashion similar to the auto white balance mode on your camera. The rest are the presets we have discussed, whereas “Custom” is any setting you manually enter using the Temperature and Tint sliders.
Another way to set white balance in Adobe Camera Raw is to use the White Balance Tool, found in the main toolbar, shown highlighted below:
After selecting the tool, click on an area of the image that should be a neutral gray or white. The Temperature and Tint sliders will automatically adjust to make the selected color exactly neutral, but it will also shift the color balance of the entire image. Sometimes the White Balance Tool works really well, but sometimes it doesn’t, especially if you have selected something that really shouldn’t be neutral or if your scene was lit by mixed light sources. If you don’t like the results, just manually adjust white balance until you get something that works.
What is the best white balance setting?
The best white balance setting varies from scene to scene and depends largely on your own personal artistic tastes. Of course, you shouldn’t feel that you have to remove color bias from a photo—I sometimes even adjust white balance to intentionally introduce a color bias for artistic reasons. For example, I selected the Daylight setting for the cave image below, even though it introduced a warm color cast to the image, which I preferred to the flat colors produced by the “correct” white balance. I encourage you to experiment with various white balance settings for each image, assessing multiple options until you find the color balance that appeals to you the most, in the process learning how white balance choices affect the colors of a given scene. This exercise will allow you to “pre-visualize” white balance while in the field, thus expanding your creative options.
“Mysterious Earth”—Rio Frio Cave, Belize. I used white balance to warm up the colors in this photograph, entirely for artistic reasons.
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