Color is one of the "compositional elements" of an image, which also include line, texture, tonal contrast, shape, pattern, shadow, and all the other factors that are part of the design (composition) of an image. Because color is powerful, it tends to dominate all the other elements, which is one reason why some photographers work in black-and-whitethe absence of color concentrates the viewer's attention on the other elements of the composition.
To make a strong color image, you need to understand the power of color and know how to harness it. Two of your camera's functions can help you to control the way that the camera records the color in a photo: white balance and Picture Style.
Controlling the White Balance
One purpose of the white balance setting is to help you take photos with a neutral color balance. The easiest way to tell whether a photo has a "color cast" is to look at the white tones in the image. They should look truly white, rather than orange or blue.
We need to control white balance because the color of light changes according to the source of the light. Most light sources are candescent in nature, and the color of light they emit is measured on the Kelvin (K) scale. Here are some examples:
- Light from a candle has a deep red-orange color cast and measures around 2500K.
- Sunlight at midday measures around 5200K.
- Light under an overcast sky measures around 6000K
- Light in the shade on a sunny day measures around 7000K.
Light sources with a low color temperature create light with an orange color cast. Light sources with a high color temperature create blue light.
Your camera can compensate for these color casts. The easiest way to achieve this result is to use the camera's auto white balance mode (see Figure 1), which tells the camera to counter the color temperature of the light source by applying a color cast opposite that of the photo. For instance, the light from a tungsten bulb (color temperature around 3200K) has an orange cast, so the camera applies a blue cast to compensate. At the other end of the Kelvin scale, if you take a photo in the shade on a sunny day, the light has a high color temperature (around 7000K), and the camera applies an orange color correction to compensate for the blue cast. Quite simple, really.
Adjustments like these are fine in theory, but in practice you'll want your photos to have a neutral color balance only occasionally. Color neutrality is a concern for professional photographers, who need precise control over white balance for activities such as photographing product shots or weddings. For artistic photography, it's more interesting to use the inherent color of light creatively.
Figure 1 White balance settings on my EOS 5D Mark II.