Part 24c - White Balance

Parts 24a and 24b may be as much as you need or want to know about white balancing your DSLR. On the other hand, even though this is a primer for the beginning DSLR user, you may occasionally have the need for even more precise white balance control. Part 24c is written for you.

One of my wife's hobbies is creating Temari balls. These decorative accessories are fashioned out of Styrofoam balls, covered with a base color thread and then overlaid with creative designs. OK, it's probably easier just to show you a Temari ball:

Figure 1 - Temari Ball with correct color rendering

My wife is particular about the colors when I photograph her final creations. Since others might use her pictures to attempt the same project, the correct rendering of thread colors is important. You may also have similar situations where color rendition is critical.

The white balance controls we have discussed in Parts 24a and 24b will get you close. But these white balance corrections are generic and applied by the manufacturer -- not to YOUR specific lighting conditions.

This article will discuss two options for performing a critical white balance adjustment to your DSLR. The techniques are slightly more involved, but once you have walked through the process once or twice, it will seem easy.

So, let's set up the shooting situation:

• assignment: shoot a picture of wife's Temari ball collection with proper color rendering
• lighting: a table lamp (tungsten) like you might have in your home

From our previous discussion, you know that this lighting situation is challenging and significantly different from an outdoor daylight situation.

It will help if we visualize the problem before tackling a solution.

Figure 2 - Kodak Color Reference Chart

To help in this visual demonstration, I will insert the card above in each example. This is a Kodak color reference chart used by professionals when they are balancing their images.

Figure 3 - Temari ball set up using daylight white balance setting

Yikes! Something's wrong here - Figure 3. It doesn't take a color expert to see that this picture, taken using the daylight white balance setting, is skewed to the yellow and red portions of the color spectrum. Use the white patch on the Kodak chart to see how far off the path it is from true white. If one color is wrong, then they are all wrong.

Of course, there are other white balance options. We could have taken this picture using the automatic white balance DSLR setting - Figure 4.

Figure 4 - Temari ball set up using the Auto White Balance setting

Well, auto white balance is a little better. But it is far from correct. Notice the white patch is still far from true white. It still retains a yellow and red cast. If this white is wrong, then all the colors must be wrong.

We did learn that DSLRs contain a white balance selection for tungsten lighting - Figure 5.

Figure 5 - Temari ball set up using Incandescent White Balance setting

Much closer. Using the camera's incandescent white balance setting, the white patch is almost white and the gray background color in the top half of the Kodak chart is very close to gray. But the color is still not correct.

Why not? Remember the white balance settings are created by the camera manufacturer. They must necessarily make some compromises. Since incandescent lights all "burn" at slightly different color temperatures, camera makers must strike a middle ground and use an average tungsten temperature value for their "norm". Unfortunately, that "average" is not exactly correct for the table lamp light I was using to take this picture.

Is all lost? Hang in there, technology will come to our rescue. Most DSLRs accommodate this situation by incorporating the ability to create a "custom" white balance. I will be using a Nikon DSLR to create a custom white balance for this scene, but the function can be found on most current DSLRs. Be sure to check your camera's manual for the specific directions for establishing a custom white balance.

Custom Color Balance Option 1:

If we can provide a known reference, then a custom color balance can be created.

Figure 6 - White card in place to create a custom white balance

The known reference must be a white or gray card that can be placed in the scene. Figure 6 shows a white card placed in the Temari ball set up. (This specific picture was taken using the incandescent setting on my Nikon DSLR. This is as close as the manufacturer's white balance setting could get this picture. See Figure 5.)

Once the card is placed in the scene, here are the steps for creating the custom white balance setting:

1. move close enough to the scene that only the white card can be seen through the viewfinder
2. set the camera to any shooting mode setting except AUTO
3. set the camera white balance setting to "Preset"
4. hold down the WB (white balance) button until "PRE" begins flashing in the control panel
5. take a picture
6. the word "GOOD" will appear in the control panel (If the word GOOD does not appear, try again -- starting with step 4.)

That's it. The camera has adjusted its color settings based on rendering the paper it "saw" in front of the lens to produce the color white. You can now take as many pictures as needed. The white balance will remain the same until you change your white balance control setting.

My resulting picture is shown below:

Figure 7 - Custom white balance Temari balls using the white card method

Custom Color Balance Option 2:

For even more precision, there are companies making white balance accessories that work on any DSLR and have the ability to generate custom white balance settings.

For this example, I am using a COLORRIGHT attachment on my Nikon DSLR.

Figure 8 - ColorRight white balance calibration cap shown with a Canon DSLR

Using my Nikon camera, here are the steps for creating a custom white balance:

1. set the camera to any shooting mode setting except AUTO
2. set the camera white balance setting to "Preset"
3. hold down the WB (white balance) button until "PRE" begins flashing in the control panel
4. place the ColorRight cap against the front of the lens filter ring with the dark side facing the camera
5. take a picture
6. the word "GOOD" will appear in the control panel (If the word GOOD does not appear, try again -- starting with step 4.)

Like the white card method, this setting will remain in effect until you manually change the white balance control setting. So shoot away.

I have found the ColorRight white balance cap to be very accurate and much easier to carry into the field and keep clean than a white card. At $89, the white card is cheaper. But, for convenience, accuracy and ease of use the ColorRight device is exceptional.

Here is the final picture of the Temari balls using the ColorRight device to create a custom white balance setting on my Nikon DSLR.

Figure 8 - Temari balls using ColorRight custom white balance

And officially wife-approved.

Although you have probably learned more about Temari balls than you ever wanted to know, I hope Parts 24a, 24b and 24c have answered your white balance questions and provide you with an understanding of the importance this control plays in the color rendering of your final images.

Finally, there are also ways of adjusting white balance in today's digital imaging software. A discussion of methods for correcting white balance after the picture is taken and stored on your computer can be found in Hub's iDarkroom blog.