Light. Light is made of all the visible spectrum from red to violet with everything in between. It also goes beyond what we can see into the infrared and the ultraviolet. But we are here to talk about what the human eye sees and what your camera sees. Surprisingly, they are vastly different.
Not all light is created equal. I’m not talking about the quality of light, but rather the color of light. What you might see as white light from different sources can actually have different colors, or what are referred to as color temperatures.
Direct sunlight at noon (which I’ll just refer to as sunlight) is considered to be a “normal” color temperature, so all light sources are compared to this as the standard. For example, light from an incandescent light bulb appears to be more orange than sunlight. On the opposite side of the spectrum, shady areas appear to be bluer than sunlight. In photography, we refer to these differences as being “warmer” (or more orange) and “cooler” (or more blue) than our neutral sunlight
Your camera has controls for this. It’s called “White Balance”. White balance balances the color temperature in your image. How does it do this? It adds the opposite color to the image in an attempt to bring the color temperature back to neutral. Instead of whites appearing blue or orange, they should appear white after correctly white balancing an image.
Most cameras come with the option to manually set or adjust white balance. Typical settings include “sun”, “shade”, “tungsten” and “fluorescent”. Some cameras come with the option to manually set a color temperature.
If you just don’t want to worry about color correction after the image is taken, most cameras come with the option to use auto white balance, or AWB. With AWB, your camera evaluates the scene that you’re photographing and decides on the best white balance to use. It will typically reference a neutral color in your scene such as white or grey to determine the correct white balance. Depending on your camera and the scene you’re photographing, your results will range from perfect to not very close at all.