WHITE BALANCE: CHOOSING A NEUTRAL REFERENCE
A neutral reference is often used for colour-critical projects, or for situations where you anticipate auto white balance will encounter difficulties. Neutral references can either be parts of your scene (if you’re lucky), you can use a WB card set which you carry with you.
A WB reference card (like the one pictured above) is always more accurate then a “neutral references from your scene”, since it can easily be tricked into thinking an object is neutral when it is not. Portable references can be expensive and specifically designed for photography, or may include less expensive household items. An ideal gray reference is one which reflects all colours in the spectrum equally, and can consistently do so under a broad range of colour temperatures.
How to Perform a Manual White Balance
You should perform this procedure at the beginning of every shoot, and every time the lighting conditions change. It is especially important to re-white balance when moving between indoors and outdoors, and between rooms lit by different kinds of lights. During early morning and late evening, the daylight colour changes quickly and significantly (although your eyes don’t notice, your camera will). Do regular white balances during these periods.
- If your camera has a filter wheel (or if you use add-on filters), make sure you are using the correct filter for the lighting conditions.
- Point your camera to a pure white subject (e.g. the white on a WB card set), so that most of what you’re seeing in the viewfinder is white. Opinions vary on just how much white needs to be in the frame – but we’ve found that about 50-80% of the frame should be fine (Sony recommends 80% of frame width). The subject should be fairly matte, that is, non-reflective.
- Set your exposure and focus.
- Activate the white balance by pressing the button or throwing the switch. The camera may take a few seconds to complete the operation, after which you should get a message (or icon) in the viewfinder (depending on which camera your using). Hopefully this will be telling you that the white balance has succeeded – in this case, the camera will retain it’s current colour balance until another white balance is performed.
Note: You can trick the camera into reading an inaccurate white balance, in order to make the pictures appear warmer (more orange) or cooler (more blue). but more about that another time