Week 3: Colour of LightPosted: Monday May 10, 2010 Today's Challenge: Custom White BalanceThe subject of this lesson is the color of light, and the point is to help you use your knowledge of it to enhance your photos. All colors of light have an actual color temperature measured in Kelvin, but for the purpose of this lesson our main focus is the color cast and not the specific temperature of the light.(For most real world use it's not necessary to know the Kelvin temperatures unless you are using a high-end photo editing program for post-processing.)
All light emits a particular color. Sunlight, although referred to as "white
light," actually contains all the shades of the color spectrum. So even when you are using natural light for your photos there can be a color variance, or "cast," based on the portion of the color spectrum that is
visible to our eye.
Outdoors
For instance, on a clear, bright day outside you'll often encounter a soft yellow cast in morning photography, a cooler, bluer color cast at mid-day, and a warmer, orange color cast in afternoon photography. (Also, take note that in morning and evening light your photos will have a softer contrast as compared to the harsh, strong contrast found in the middle of
the day.)
Indoors
Indoor light, however, is where we can run into a few problems with color cast. Artificial light creates a color cast that may not be readily apparent to the naked eye, but will become immediately obvious when photographed. The two main types of indoor light are flourescent and incandescent bulbs. Flourescent lights, often found in office environments or warehouse superstores, can give off a green or purplish cast. Incandescent lights, often found in our homes, tend to give off a yellowish/ orange color cast. (As opposed to a soft yellow light outdooors, the yellow light found indoors tends to be overbearing and unpleasant.)
Since purple, green, and strong yellow casts can be rather unflattering to our subjects, indoor lighting requires more work. This is where White Balance comes into play. White balance is simply a fancy way of setting the color temperature of your image. The human eye is very adept at compensating for color changes in light and allowing us to view light in a very large spectrum. Most film cameras handle white balance in the film itself and you simply purchase film to match the lighting situation. Camera sensors, however, are not quite as intelligent, and they
must be told what color the light is for a given situation in order to compensate for that color. To help with this, digital cameras come with some pre-set white balance settings such as Auto (AWB), Daylight, and Tungsten, among others. Properly setting your white balance for your lighting situation will greatly increase the impact of your photos and decrease the amount of time you spend editing them. White Balance settings will vary from camera to camera.
Challenge: Custom White Balance 1. Photograph an object (or people, as long as they're willing to sit still for a bit) in your house the way you typically would, using the auto white
balance setting (often indicated as AWB.)
2. Now select the tungsten white balance setting (usually the icon for this setting is an upside down lightbulb) and take the photo again.
3. Grab a piece of white paper, posterboard, or cardstock, large enough to fill the frame of your lens.
4. Follow the steps in your manual to set your custom white balance.
5. Using your custom white balance, take your photo again.
6. Upload your photos and compare.
Auto:
Tungsten:
Custom: 
