Beyond Point-and-Shoot

Photography Fundamentals: White Balance

Adapted from Beyond Point-and-Shoot (Rocky Nook)

By Darrell Young

Back in the good old days photographers bought special rolls of film or used filters to meet the challenges of color casts that come from indoor lighting, overcast days, or special situations. Each type of light you shoot under has a particular Kelvin color temperature (tint). Your camera needs to know something about the color of the light your are shooting under so it can balance itself and keep white truly white and keep other colors accurate.

You can manually balance your camera’s colors with its white balance controls, or let the auto white balance system do it for you. Fortunately, auto white balance does a great job for general shooting. However, discerning photographers learn how to use the white balance controls so they can achieve color consistency in special situations, such as when shooting a series of product shots where the color must remain consistent.

How Does White Balance Work?

Normally you will use white balance to adjust the camera so that whites are truly white and other colors are accurate under whatever light source you are shooting. You can also use the white balance controls to deliberately introduce color tints into your image for interesting special effects.

Image with different white balance settings

White balance color temperatures are exactly backwards from the Kelvin scale we learned in school for star temperatures. Remember that a red giant star is cool, and a blue-white star is hot. White balance color temperatures are backwards because the white balance system adds color to make up for a lack of a particular color in the light that is shining on your subject.

For instance, under fluorescent light, there is not enough blue light, which makes your subject appear greenish yellow. When blue is added, the image is balanced to a more normal appearance. White balance in cameras adds colors to balance the camera for the current light source.

Another example is when you shoot on a cloudy, overcast day. The cool ambient light could cause the image to look bluish if left unadjusted. The auto white balance control in your camera sees the cool color temperature and adds some red to warm the colors a bit. A normal camera white balance on an overcast day might be about 6000 K (Kelvin), which will warm up the cool bluish look. We’ll discuss color temperature shortly.

Just remember, we use the real Kelvin temperature range in reverse, and in photography reddish colors are warm and bluish colors are cool. Even though this is backwards from what we were taught in school, it fits our situation better. Just don’t let your astronomer friends convince you otherwise. To photographers, blue seems cool and red seems warm. Doesn’t cold snow look bluish white? Isn’t a beautiful sunset nice and warm?

Let’s examine how color temperature affects your images and then see how to adjust the camera to achieve those effects.

Color Temperature

The white balance for many cameras can range from a very cool 2500 K to a very warm 10000 K (some cameras have less range).

The illustration below shows the same landscape picture with three color temperature settings. Notice how the image in the center (5000 K) is about right for normal sunlight, and the image on the left (2500 K) has a cool bluish cast and the one on the right (10000 K) has a warmer reddish cast.

A landscape shot with three color temperatures

The same adjustments we made with film and filters in the good old days can now be achieved with the white balance settings built into your camera. It should have several white balance settings with names like cloudy, shade, and fluorescent.

To make a warmer-than-normal image, simply select the cloudy white balance setting while shooting in normal daylight. This sets the camera white balance to about 6000 K, which makes nice warm-looking images. If you really want to warm up the image, choose the white balance setting called shade, which sets the camera to about 8000 K. On the other hand, if you want to make the image appear cool or bluish, try using the fluorescent (4200 K) or incandescent (3000 K) settings in normal daylight.

Remember, the color temperature shifts from cool values to warm values. Your camera can capture images with various manual white balance settings. Some cameras can be set to any color temperature from 2500 K (very cool or bluish) to 10000 K (very warm or reddish) or any major value in between.

In the film days we had to carry different film emulsions or filters to deal with the color temperature ranges of light. Your digital camera has very easy-to-use color temperature controls and a full range of color temperatures.

Each camera has a certain way of setting white balance manually. When you use the manual controls and take your camera out of auto white balance mode, you have control over the way the camera will record the current color temperature of the ambient light. You can introduce color tints by deliberately setting the wrong white balance.

Below is a picture of a person taken in direct sunlight with the camera set to fluorescent white balance. Since the camera added blue to the picture to adjust for a shortage of blue in fluorescent light, your picture will have too much blue because there is plenty of blue in sunlight.

Deliberately using the wrong white balance setting to add a blue tint to a picture

Manual white balance settings are usually needed only when you must have consistent color from image to image or when you want to create special effects; otherwise, auto white balance will do fine for most people. Check your camera manual to learn how to manually adjust white balance.

You can choose preprogrammed white balance settings on most cameras. The names and number of white balance settings vary from camera to camera. Each of the white balance settings are designed for use under the type of light for which the setting is named. The settings generally include the following:

  • Auto: With this setting the camera will decide what the correct white balance is for the scene it sees through the lens. It will adjust the white balance for each picture you take, so you may not have consistent color. That is not a bad thing for most photography since the white balance will vary by only a few degrees Kelvin between each shot. Most people simply leave their cameras set to auto white balance.
  • Incandescent: This type of lighting is gradually being phased out. The old standard in- candescent light bulb gets hot and uses too much energy. Most people don’t realize that the light output of an incandescent bulb is rather orange, or warm. If you are shooting under incandescent light, your images may be objectionably warm, with orange skin tones and whites that are not white. Test your camera’s auto white balance ability under incandescent light by shooting a picture of someone reading a book under an old-style light bulb. Look at the picture on your computer and see if the pages of the book look reddish or orange. If not, your camera does a good job with incandescent light. If the pages look orange, you can manually set the camera to the incandescent white balance setting and take another shot. You should see a big improvement.
  • Fluorescent: As mentioned earlier, fluorescent light has a deficit of blue, so your subjects will come out looking greenish. If you take pictures of people under fluorescent light and they look a sickly green or yellow, set your camera to the fluorescent white balance setting and shoot again. The camera will add blue and the image will look more normal. Some cameras offer several fluorescent white balance settings because there are several types of fluorescent light.
  • Sunlight: When you are shooting outside under direct sunlight, the color is somewhat neutral and tends to be warm. Using this setting will balance your camera for shooting under direct sunlight.
  • Flash: When you use a flash unit, whether it’s a popup unit built into your camera or an external unit mounted on your camera, you can set the white balance to flash and the camera will record consistent color for most flash units.
  • Cloudy: On a cloudy or overcast day the light has a blue tint that can make images seem cool. When you set the camera to cloudy white balance, it adds red (warmth) to the image so it looks more natural. You can also use the cloudy setting (and many people do) when you want to warm up any of your images. Most people prefer the look of warm images. Some people even leave their white balance set to cloudy all the time. Usually those photographers grew up shooting daylight film and using an 81A warming filter on their lenses all the time. I don’t recommend setting your camera to the cloudy white balance setting all the time because, in some instances, the extra-warm images will not look as good. For instance, if you are shooting pictures of people in evening sunset light, the ambient light is already very warm looking. If you add more warmth by setting the camera to cloudy white balance, your subjects’ skin may have a too-warm, reddish-orange look. Some photographers do not agree with me, but I don’t believe that one settings works for every picture, so I don’t leave my camera set to cloudy all the time. Experiment with the cloudy white balance setting under various light sources and see what you like.
  • Shade or shady: Light in the shade is very blue, primarily because the warm light of the sun is not shining on the subject. If you set the camera to shady white balance, it will add a lot of warmth to the image.
  • Kelvin or K: Not all cameras have this setting. It allows you to choose a specific Kelvin color temperature for your images. Most cameras that have this setting will let you choose from temperatures as cool as 2500 K to as warm as 10000 K.
  • Measure or PRE: This setting has different names on various cameras. You can manually measure white balance with a gray card or white card and the camera will use that white balance setting for accurate color under that one light source. Manual white balance readings can be used anytime you think the camera is not handling the color consistently in auto white balance, and yet you are unsure what white balance setting to use (e.g., fluorescent, cloudy, or shade). For instance, are you sure a fluorescent bulb is cool white, or is it daylight, or maybe warm white? If you cannot accurately identify the color temperature of a particular light source, you can simply measure or read the light by letting it shine on a gray card or white card (available in camera stores or online) and then have your camera read the color temperature from the light reflected off the card. Since the gray card or white card is a known color, the camera can balance itself so the gray or white is the correct color under the light source you are using. It will color balance the pictures so they do not have an odd tint. The illustration below shows a gray card set like the one I use. I got mine on the Michael Tapes Design site.

WhiBal gray card kit with various sizes

You don’t need to be overly concerned about adjusting your white balance often; however, when the circumstances require it, you should know how to manually white balance your camera. At the very least you need to understand what the camera is doing when it is using auto white balance and learn to recognize when an image has bad white balance (tint in the picture).

Understanding white balance in a fundamental way is simply realizing that light has a range of colors that go from cool to warm. We can adjust our cameras to use the available light in an accurate and neutral, balanced way that compensates for the actual light source, or we can intentionally allow a color cast in our images by unbal- ancing the settings.

If you decide to turn pro you will need a good understanding of white balance and should learn to do manual white balance readings from a gray card or white card. Check your camera manual to see if your camera requires either gray or white. Most use either, but some may accept only one color.

In any case, all enthusiast photographers should at least buy a cheap paper gray card, read their camera manual to find out how to manually set the white balance, and retain that knowledge for later use.

White Balance and RAW Mode

Should you worry about white balance settings if you shoot in RAW mode? After all, you can modify a RAW file after the fact.

The quick answer is no, but that may not be the best answer. When you take a picture using RAW mode, data is written to the memory card with no white balance, sharpening, or color saturation information applied. Instead, the information about the picture’s settings are stored as markers along with the raw black-and-white sensor data. Color information is permanently applied to the image when you post-process it and save it to another format, like JPEG or TIFF.

When you open the image in a RAW conversion program, the camera settings are applied to the data in a temporary way so you can view the image on your computer screen. If you do not like the color balance, or any other setting you used in-camera, you can simply change it in the conversion software and the image looks as if you used the new setting when you took the picture.

Does that mean I am not concerned about my white balance settings since I shoot RAW most of the time? No. The human brain can quickly adjust to the colors in an image and perceive them as normal, even when they are not. This is one of the dangers of not using the correct white balance. Since an unbalanced image on your computer screen is not compared to another correctly balanced image side by side, there is some danger that your brain may accept the slightly incorrect camera settings as normal and your image will be saved with a color cast.

As a rule of thumb, if you use your white balance correctly at all times, you will consistently produce better images. You will do less post-processing if the white balance is correct in the first place. As RAW shooters, we already have a lot of post-processing work to do. Why add white balance corrections to the workflow? It is just more work, if you ask me!

Additionally, you might decide to switch to JPEG mode in the middle of a shoot, and if you are not accustomed to using your white balance controls, you’ll be in trouble. When you shoot JPEGs, your camera will apply the white balance information directly to the image and save it on your memory card—permanently. Be safe; always use good white balance technique!

White Balance Ambient Light Reading Tip

When you measure ambient light with a gray card or white card, keep in mind that your camera does not need to focus on the card. In white balance ambient light reading mode—or whatever your camera calls this mode—it will not focus anyway since it is only trying to read color temperature values, not take a picture.

The important thing is to put your lens close enough to the card to prevent it from seeing anything other than the card. The correct distance for most lenses is three or four inches (about 75 to 100 mm) away from the card.

Be careful that your lens does not cast a shadow onto the card in a way that lets your camera see some of the shadow. This will make the measurement less accurate. Also, be sure that your source light does not produce glare on the card. This is not a common problem because most gray cards have a matte surface; however, it can still happen. You may want to hold the card at a slight angle to the source light if the light is particularly bright and might cause glare.

Finally, when the light is dim, use the white side of the card (if your camera supports white) since it has more reflectivity. This may prevent a bad reading in low light. The gray card may be more accurate for color balancing, but it might be a little dark for a good measurement in dim light. If you are shooting in normal light and your camera supports it, a gray card is best for color balancing. You might want to experiment in normal light with your camera to see which you prefer.

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Beyond Point-and-Shoot by Darrell Young. Adapted with permission from Rocky Nook. Copyright 2012.