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"Color Temperature", "Color Balance", "White Balance". People new to photography, digital or traditional, often have a difficult time visualizing what these terms refer to initially. And even those who are familiar with these terms may not have a clear understanding of how they all work together.

This is the second of two lessons on this site focused on color temperature, color balance and white balance. The first lesson, entitled "Using Digital White Balance Indoors", examines color balance and lighting indoors, while this lesson runs through similar techniques for outdoor situations.



(Click on any image below for an enlarged view.)

Topics Covered:

  • Defining Color Temperature, Color Balance, White Balance
  • How digital cameras relate to Color Temperature
  • Adjusting the White Balance in a digital camera to various presets
  • Creating a custom White Balance setting
  • Differences between strobe, tungsten, fluorescent lights, and daylight
  • Creating a negative fill

Equipment Used:
You can click on the blue links below for more info.

 

Color Temperature
In essence, color temperature refers to the frequency of color that can be measured from any particular light source. The efficiency of our own visual experience, however, can make the idea of color temperature somewhat confusing.

This is because our eyes have the intrinsic ability to adjust to color shifts such that a white piece of paper will appear white regardless of what type of light is being cast on it. However, color shifts can be much more apparent in situations where there are two or more light sources of differing color temperatures, like the relatively yellow light that emanates through the windows of a house contrasted against the blue light of dusk.

 

Color temperature is measured in degrees Kelvin. The most important thing to remember about color temperature is that the higher the Kelvin number, the more blue the light source. The following chart illustrates an approximate color temperature scale (figure 1).



Figure 1

 

Color Balance
Color balance is achieved when a color recording device (like a camera) renders an image close to how the human eye perceives it. White Balance settings, film type, colored filters and gels can all help to assist the device in achieving "accurate" color. Alternately, you can also throw the color balance off to render a different mood or effect to an image.

White Balance
If you shoot with a film camera and want to achieve color balance in a daylight setting, you would use daylight film to match the color temperature of daylight. If you shoot with a film camera indoors with incandescent lighting, you would either choose Tungsten film or place a Tungsten filter over the lens to balance the color temperature. If you are shooting digitally, however, achieving color balance in any lighting situation is just a matter of setting the White Balance (WB) in the camera.

 

In the diagram to the right, you can see how different White Balance settings can affect the color balance of a shot. Remember that if you can match the color temperature of your light source with the correct White Balance setting, you will get color-balanced, or "neutral" results.

Click on the image to enlarge if you are having trouble reading the text.



Figure 2

 

To further illustrate how the White Balance function works, we decided to take a few outdoor portrait shots using different color temperature settings and lighting techniques. We wanted to shoot against a background that was neutral in color to clearly illustrate the shifts in color, so we went up onto the roof of our studio and set up against the shadow side of a neutral gray wall.

 



Figure 3

Our model stood with the sunlight raking across the side of his face and we set the camera on a tripod and framed up the shot (figure 3).

 

Before shooting, we made some adjustments to the camera. We first set the Exposure mode to Manual, set the Focusing mode to MF, set the ISO to its lowest setting (100), and set the Image Quality to TIFF. To learn more about adjusting these settings, check out the EVOLT E-500 Basic Startup lesson located on this site.

Since we were shooting outside, where the color temperature is roughly 5300K, we should have used the 5300 Preset WB setting to match it. But for comparison purposes, we decided to first set the WB to the Tungsten preset (3000K), which is designed to color balance a household Tungsten light source.

 

In order to select this White Balance preset, first press and hold down the small WB button at the back of the camera and then turn the Control dial to select the LIGHT BULB icon (figure 4).



Figure 4



Figure 5

Since we wanted the model's eyes to be in sharp focus and for the background to be relatively soft, we opened the aperture up to f/4 (the wider the aperture, the more selective the focus). We then set the shutter speed to 1/500th of a second to render a good exposure, focused and took a shot (figure 5).

 

Notice how blue the result is! With the White Balance dialed to LIGHT BULB (3000K), the camera was set to record our subject illuminated with Tungsten light. But since our model was lit by the relatively cool light of the sun (review figure 1), the result looks as though a blue filter had been placed over the lens. Keep in mind, however, that shooting at an "incorrect" color setting can sometimes render an interesting look.

At this point, we had a few options for achieving color balance. We could dial the White Balance to the 5300 Preset, manually select a Custom WB setting in 100K intervals, or we could create a One Touch White Balance setting. Here, we opted for the One Touch, since we didn't know the exact color temperature and wanted to achieve exact color balance. Here's how to set the White Balance to neutralize any single light source.

 

One Touch WB
To use the One Touch function, first press and hold down the WB button on the back of the camera and use the Control Dial to select the One Touch icon.



Figure 6



Figure 7

Next, point the camera at a white piece of paper or neutral gray card (photo supply stores carry these in various sizes) and fill the frame. Make sure that your exposure settings will allow you to capture a good exposure (one that's not too light or too dark).

Press and hold down the One Touch button on the back of the camera, and then press the shutter button all the way down to record a White Balance setting. If the exposure is good, the screen will prompt you to record the setting. Press OK.

You are now ready to capture perfectly color-balanced pictures. Once this setting was made, we took another shot (figure 8).



Figure 8

 

Now the color in our result is much more natural looking. However the lighting of the shot is very high in contrast. Notice how the sun rakes sharply across the model's face. In order to soften the sunlight, we attached a 42" Translucent LiteDisc to a LiteDisc Holder, secured it to a LiteStand, and positioned it in between the model and the sun.

While this softened the light falling on the model, it also reduced the level of light falling on him by a full f-stop. To compensate for exposure, we slowed the shutter speed to 1/125th of a second and took another shot (figures 9 & 10).

 

 

Notice the differences in the result shot. The contrast has been cut way down and we are now able to make out the details of the model's eyes. Also notice that the gray wall has lightened a full f-stop due to the change in shutter speed.

To illustrate other Preset WB settings against daylight, we then switched the One Touch WB setting to the White Fluorescent preset, measured at 4000K (relatively green), and took a shot (figures 11 & 12).

 

 

Notice how the color cast resulted in a strong magenta. Again, this is because when the camera is set to 4000, it is in effect ready to neutralize light with a relatively green cast to it. Think of the camera as adding a specific color to neutralize the color of the light source.

 



Figure 13

When the camera captures light that lacks the green cast, it is stuck with an image that is, in effect, recorded with a magenta filter over its lens. The color wheel to the left illustrates these complementary colors (figure 13).

 

Afterward, we switched back to the One Touch setting and decided to make a subtle change to the lighting setup.

While the Translucent LiteDisc worked to diffuse the light of the sun, there was also another light source affecting the right side of the model's face: the ambient fill light of the sky to the right of the model. Sometimes a sky fill works beautifully, and sometimes you will want to modify the fill light so that it is either lighter or darker. To lighten the fill, you might try positioning another LiteDisc, either White or Soft-Gold, to the opposite side of the main source to bounce light into the shadows, or, as was the case here, you may want to create a "negative" fill to increase contrast and a sense of dimension.

To create a negative fill here, we set up a 42" Black LiteDisc and positioned it to the right of the model to both block the ambient light of the sky and to absorb the light passing through the Translucent LiteDisc. Once it was in place, we took another shot with the same settings (figures 14 & 15).

 

 

The result shows a nice lighting ratio, particularly for men: diffused light gradually falling off across the face to a subtle shadow along the right side accentuating the lines of the nose, cheekbone and jaw line.

It's good to keep in mind, however, that there is no definitive way to light a headshot. The architecture of each person's face is unique and as such may require a very different lighting approach. It will only help you to experiment and develop different lighting techniques and White Balance settings for different situations.

 


Equipment Used:
You can click on the blue links below for more info.

Recommended Links

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