Missing Pages: White Balance

Introduction | I: ISO Setting | II: Program AE | III: Aperture & Shutter Priority | IV: White Balance | V: Depth of Field | VI: Bracketing | VII: Megapixels | VIII: Flash Modes

The Missing Pages column is a collection of all of the information that should have been included in your camera’s Owner’s Manual—but somehow got left out. This is a hybrid assortment of short articles that delivers the know-how you need to derive the maximum enjoyment—and creative expression—from your equipment.

It’s sort of a juiced-up User Guide for creative people who are not necessarily technical. Each part will teach you how to use one of the camera features or functions that you previously ignored or left set on Auto. And each will include a Creative Project so that you can try some scripted experimentation.

We will explain complex technical subject matter a way that everyone can understand. And if you happen to be a technical expert yourself, we’re including “Nerds Only” sidebars just for you. That way you can dig in deep—or just straddle the edges—of the technological stuff. It’s your decision.

Installment IV: White Balance

Definition: Determination of the exact color adjustment necessary for a digital camera to render a pure white object so that it appears pure white in the captured image.

The assumption is that if white is rendered correctly, all of the other colors will be also. Conversely, if white has a color cast, it doesn’t matter if the other colors are right—the picture will look wrong.

Lo, the human brain! Among its many wonderful talents, your brain has the ability to restore proper coloration to most of the physical objects your eyes see. If you’ve ever shot daylight-balanced 35mm film under normal tungsten incandescent light you doubtlessly produced images that were brownish-reddish—even though the scene looked normal when you viewed it firsthand. Psychologists have told me the brain makes “corrections” to the signals it receives from the eyes because that’s way the brain copes with altered reality. Your brain replaced the blue coloration that was missing from the scene because it needed to keep things normal-looking.

This ability may be rooted in our evolution from animals that needed to be able to detect subtle color differences in plants so that they could determine which were edible, ripe or spoiled regardless of the time of day or lighting conditions. That’s just my guess, but I’m sticking with it since most human characteristics are one way or another related to survival.

Cameras need help to make these adjustments. Yes, many have Auto White Balance settings. But like many of the other Auto settings, the results are usually pretty close but rarely dead-on accurate. Cameras also offer Preset and Custom settings. More on those later.

First, let’s dispel the misconception that you can easily correct for White Balance miscalculations by using Photoshop. Experts can salvage some poorly balanced images and many people can make the images look better, but there’s no substitute for getting the white balance set correctly in the first place.

White Balance is not difficult to do or hard to understand. In fact, at the most basic level, all you really need to consider are three colors: our old friends R, G and B.

The spectrum of visible light ranges from R (red) to B (blue), or more correctly, from near-infrared to near-ultraviolet. Light color is determined by its wavelength, so it can be objectively measured, filtered and altered. White is a mixture of all colors (even though that may sound counterintuitive). Pure white objects reflect all incident light in the 400-700nm (nanometer) range.

Color is objectively identified by its temperature, which is expressed in degrees Kelvin. A color temperature meter will tell you that noon daylight is around 5,500 degrees and that normal room light generate by a GE Softwhite tungsten light bulb is closer to 2,900 degrees. On a cloudy day, the color temp might be in the 6,600 to 8,800 range. We call reddish light in the 3,000 degree range “warm” and bluish light in the higher 7,000 degree area “cool” even though the numerical value of the cooler temperature is higher. Remember it this way: fire is red and warm; ice is blue and cool. Despite the fact the labels are opposite of what the Kelvin thermometer suggests.

We forgot green, and sadly, many color temperature measuring devices do likewise. In reality it’s as important to achieve the correct balance between Green and Magenta as it is between Red and Blue. In the old says, color temperature meters—with the notable exception of the tri-color Minolta Color Meter III—could read only Red and Blue. Which was largely okay because fluorescent lights were rarely used in the home (except in the garage).

These days the color-impaired CFL—aside from creating an environmental disaster when eventually broken—wreaks havoc on rational attempts to achieve white balance. CFL, at least some of them, burn with a ghostly greenish glow. Others are bluish-green. Some are alleged to be daylight balanced but lose traction with photographers because a) it can take 15 minutes for them to warm up and reach their operating temperature and b) their color can shift as they age. Use at your own risk.

Digital cameras allow the user to choose from Preset settings that match the average conditions found in common situations. You usually find Daylight, Cloudy, Shade, Tungsten (Incandescent) and a Fluorescent option or two. Sometimes there will be a setting for Flash and always one marked Auto. Better cameras (including virtually all digital SLRs) provide Custom White Balance which is sometimes called “Present Manual.” And some cameras allow you to select from a range of color temperatures by choosing the degrees Kelvin from a scale that starts around 2,000 degrees and tops out at about 10,000.

The Custom (or Present Manual) gets its white point value through a procedure whereby you point the camera at a solid pure white object—often a sheet of paper. The exact process differs from camera to camera, so refer to your owner’s manual. This is almost always the single most accurate way to set White Balance. Auto is the worst. The other presets, if correctly set to match conditions, range from fair to okay.

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The image that shows six panels of fruit (image left) was shot in shaded daylight with a Nikon D70s at the following settings (starting upper left): Preset Manual (Custom), Incandescent, Fluorescent. Second row: Direct Sunlight, Cloudy, Shade. The Shade preset is amazingly close (in fact, some may prefer it). The point is this: until you experiment and shoot the same scene with every different setting you have only a vague idea how they differ.

If your camera lets you pick the color temperature in Kelvin degrees, or has another mechanism that enables fine-tuning, you can have a lot of fun and enjoy substantial creative expression.

Avoid mixed light sources if at all possible. It’s extraordinarily difficult to achieve white balance in a scene illuminated by a blend of daylight, tungsten and fluorescent. The shot of the Colony Hotel, South Beach (image right) is a good example where the Auto setting produced good results. It was shot with a Panasonic TZ-7 (US name is Lumix DMC-ZS3).

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Creative Project

Sunsets and sunrises are dramatically influenced by shifts in white balance. Remember that when the sun sets, we still see its red, glowing orb even after it has physically slipped below the horizon. That’s because the long red wavelengths are diffracting—essentially “bending” over the horizon line—long after the star itself has disappeared. All of that light is red. A dissimilar thing happens at sunrise. For creative exercise, set your camera on a tripod, face the sunrise, and make exposures using every available White Balance option. Work quickly, because the color temperature of the light will change as you watch. If your camera allows Custom (Manual Preset) use that setting first to establish a baseline. Wait until sunset and repeat. This will usually require turning to face the opposite direction.

Try to use the settings in the order that they appear on the menu or dial, or write down the order that you use them. Lacking that, use the browser software that came with your camera to review the images. It will allow you to read the Metadata where you’ll find a record of the White Balance setting associated with each image.

For Nerds Only

If you feel mired down the in the details, there’s good reason for it. When we’re talking color temperature and white balance, we use the word “mired” as the contracted form of the expression “micro reciprocal degree.” Changes in color temp have a much stronger effect at the lower temperature ranges than they do at the higher. For example, a 1,000 degree shift from 2,900 has substantially more impact than a similar adjustment at 10,000 degrees. So color scientists devised a system to balance things out. The system is based on this formula: multiply the inverse of the color temperature by 10 to the exponent 6 (106). You get the same result by dividing 1,000,000 by the color temperature as measured in degrees Kelvin. Special color balancing filters called decamired filters are used to make adjustments to white balance based on these calculations.

More

Jon Sienkiewicz, your guide on this series of escapades, earned an undergraduate degree in English and then spent thirty years with Minolta Corporation, ending his career there as vice president of marketing. He was part of the team that launched the Maxxum 7000, the Dimage V and DiMAGE 7—the world’s first 5-megapixel digital camera. Along the way he directed the operations of camera repair, technical support, digital product development and digital product strategy. He grew up in this industry from Minolta SR-T 101 cameras, Tri-X film and D-76 developer right straight up and through today’s most modern cameras. As an “industry insider” he writes a monthly column for the trade paper Photo Industry Reporter, is on the masthead of three leading printed photo magazines, is contributing editor to major publications, writes a weekly blog and basically just plain loves taking pictures and writing about it.

Text ©2009 Jon Sienkiewicz.

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    • Excellent article....like you said at the begging: I FINALLY GET IT!! especially the White Balance article... looking forward to more...particularly METERING... Thanks for hellping all the newbies like me... Kind regards
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    • spectacular ... I was having some questions in my mind and your article solved them in an easy manner. Thanks thanks thanks for this article
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    • I always have confusion about  right white balance. Your article cleared a lots of my doubts. However I need to experiment as you suggested with various option. I use Nikon D90. It has Manual white balance adjustment too. Do you have any more tips to achieve a fine white balance controles always. Most of my photo taken looks reddish. Most of the time I set "day light" setting for my outdoor shootings. But still it is more reddish than what I expect,

      Thanks a lot

      Ajayan

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    • What if you shoot in AUTO WB, using RAW and a 18% Gray Card to match to colors?

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    • I bought a grey card to white balance my photos as I read a lot about how important it is. I started white balancing before photo shoots and to the most part they just looked wrong. My indoor photos under incandescent lights looked to cold and needed warming up to match how the seen looked in my memory. The same goes with sunset, they needed more red to match. I also took photos at the ski field and they needed a bit of blue as it was over cast and cold. The white balanced photos looked like a day at the beach.  I now just shoot with w/b on auto and in Raw then white balance later in lightroom to what looks right.

      Just my opinion as I don,t want to offend the author of this great article.

       

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    • I am glad that you have included the last paragraf which kind a describe my living room, where colors always came as surprise.

      Sometimes I use easy techniqe to adjust WB. I turn on the 'live view' where WB setting changes also a picture (both seen together in 'overlay'). I roll trough Kelvin degree scale and compare a display with scene in front of me till they are the same. 

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    • I do what Mircea Stanciu does. Using a gray card is safer.

      The problem with white balancing on a "pure white" object in Photoshop is that if your white object is "blown out" (over-exposed), it won't hold any color cast. It will already be "pure white" or RGB(255,255,255). This can happen even in RAW files.

      Similarly, if you try to gauge white balance in camera by pointing at the only floodlight lighting the stage (or a white object brilliantly lit by the same floodlight), you will overload your sensor and a  similar blowout will occur.

      Having said that, I frequently white balance on a gray card, then adjust w/b to taste.

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    • What Steve said is correct. RAW mode captures records the image data before white balance is applied. White balance only affects the in-camera JPG. So you should not plan to just correct a poorly white-balanced JPG later in Photoshop/Lightroom, Capture one, etc. However, you can just shoot RAW without regard to white balance and apply the white balance later.

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