In this article I will adress white balance, and colour temperature. Many people do not understand, or use white balance, so I want to introduce you to it, and explain why it is useful.
We adjust white balance to make the colours in the image as accurate as possible. Different lighting conditions have different colour temperatures (measured in kelvin) but our eyes adjust naturally, so wee dont notice. On the other hand, cameras need to be adjusted manually (there is an auto white balance (AWB) option, but this can be unreliable), so I will explain how different presets work.
Colour temperature is measured in degrees of blue and red. The more red, the ''warmer'' the scene, and the more blue, the ''cooler'' the scene.
Shade is cool and quite blue, so the ''shade'' preset adds red light to make the shade seem ''neutral'', the same applies to tungsten light, only vice versa. Tungsten i very warm, so the camera adds lots of blue light in this preset.
AWB (Auto White Balance) is the default, and may seem like the easy way out, but it not particularly accurate. Difficult lighting conitions can easily fool it, as can highly saturated colours, because it may ''see'' a colour cast, and try to remove it.
It is also not very good when photographing sunsets, because it ''sees'' a ''colour cast'', and neutralizes it, leaving a washed out, pale sky. This is why it is best to use shade or cloudy WB when photographing a sunset, because the camera adds red light, and enhances the sunset.
Below are the most common presets:
AWB:It needs no introduction: Its automatic!!
Shade: Adds red light. Good for sunsets, and shade.
Cloudy: Warm. Good for adding a warm tint to images, and cloudy conditions
Tungsten/Incandescent: Very cool. Ued to ''neutralize'' tungsten cnditions
Flourescent: Adds a hint of warmth to the cool flourescent lights.