What is white balance ?
White balance (WB) is a camera setting, originally intended for color temperature correction of the captured tonal range in a photo to match the actual color temperatures as perceived by a photographer. Ok, to be honest, although technically correct this explanation even got me confused :-).
Simply put, it ensures that the colors seen on scene by a photographer, are faithfully reproduced in the photo. Meaning white is white (not grey, blueish or yellow) etc. Now, the question is why and how would the latter even be possible ? You see, our eyes are amazing photo-sensitive devices, and they adapt to not only the amount of light available (seeing in dark), but also to the ambient temperature of the light. The camera’s sensor though, is not so adaptable, and sometimes it needs our help on understanding how to process the photo. This effect is most pronounced in so-called mixed lighting conditions.
To illustrate my point, if you look to the photo on the left, you will notice that the colors of the building(facade), and the environment have been reproduced faithfully. But wait, why are the lights in the apartment appearing to look so orange, yellowish ? They would certainly not look like that if you were e.g. inside the apartment. If you go over the photo with your mouse, you will notice that in the second image, the colors of the lights within the apartments look accurate now, but the building itself looks completely off (blue-ish wise). That is because the daylight and tungsten light (most often used in apartments) have a different color temperature.
What is Color Temperature ?
The white balance scale is based on the thermodynamic scale of Kelvin ratings as illustrated on the figure below. According to this scale, every light source is assigned a color temperature. Lower color temperature values appear “warmer” (redder), while higher values produce “cooler” (bluer) cast to the photo.
So considering example photo above, if we set white balance to daylight setting (approx 5500 K), and catch a tungsten light source – a lamp (approx 2700 K), it will appear yellow-orange to our digital camera (as seen in first photo). Consequently, if we set white balance to Tungsten setting, and catch an object illuminated by daylight light source, the object will appear blue (see wall in mouseover photo).
In most cases, if the white balance is set to auto, the camera will take care of guessing which is the most appropriate setting, and most modern cameras do a decent job of it, however, taking manual control over white balance, opens a whole new range of creative possibilities.
What are white balance presets in our digital cameras, and how do they affect the colors in the photo ?
Modern digital cameras feature several white balance presets, as well as custom settings allowing photographer complete control over the white balance. Here we will cover them briefly and mention effects they have on photos.
- Daylight (approx 5500 K): This white balance setting adjusts the digital camera to make colors appear natural when shooting in sunlit situations between about 10:00 AM and 4:00 PM (mid-day). Good thing to remember is when sun is lower in the sky with more red light, the scenes photographed using this setting will appear warmer than normally seen with our eyes. Also note that indoor scenes lit with incandescent lights(e.g. tungsten) will look very warm.
- Cloudy (approx 6000 K): Even the symbol is cloud, think of this white balance setting as Cloudy/Twilight/Sunset setting. It warms up cloudy scenes as if you had a warming filter, making sunlight appear warm, but not as much as the shade setting. You might also consider using cloudy setting for shooting people, as it will produce warm skin tones, with much more subtle effect than shade setting.
- Shade (approx 8000 K): Used for shadowed objects under blue skies, removing the blue color cast. This setting is also used to warm up the scene, and can be used for same purposes as cloudy setting, but with much more pronounced effect. We suggest that you try out both settings, and see which you prefer.
- Tungsten Light (approx 2700 K): The tungsten setting is designed to give natural results with quartz lights. It also reduces the strong orange color that is typical when photographing lamp-lit indoor scenes with daylight balanced settings. Since this control adds a cold tone to other conditions, it can be also used creatively for this purpose (e.g. make a snow scene bluer).
- Fluorescent Light (approx 4200K, 5000K, 6500K): White balance setting to be used for fluorescent lights. Since the fluorescent lights usually appear green in photos, this setting adds magenta to neutralize that effect. Usually it comes in 3 settings for finer tuning. You can use this setting creatively, if you wish to add pinkish tones to your photos.
- Flash (approx 5400 K): Lights from flash tend to be little “colder” than the daylight, so this white balance setting warms the scene a little bit up. It is very similar to cloudy setting, and can be used in similar conditions.
- Manual White Balance: Although not a preset, it is a very important tool allowing photographers to get accurate white balance in complex situations. It has no specific color temperature, but it has much wider range than the auto setting. To be able to use it, you need a reference card, so the camera can measure the color temperature of the light. Usually a sheet of white paper will work fine, or a tissue. We will cover in more detail how to set manual white balance in one of our future tutorials.
Some digital cameras also feature white balance based on temperature (K), but in that case, just refer to our color temperature scale for reference.
How to use White Balance settings creatively ?
If you understand the white balance presets and how they impact your photos, it is a good starting point for experimentation, but here are a few photography tips to get you going. Try warming up sunsets, people skin, by experimenting with cloudy/shade settings, play with fluorescent setting for some crazy effects. Also, as an example, using a daylight setting for low-light photography, can produce interesting color casts and reflections in the water as you can see from the image below.
Have fun, experiment, let us know how it went. Happy shooting.