White balance in photography refers to the color tint of a photograph, is a color seems to overlay the subjects so that their true colors are changed. Film, and the sensors of digital cameras, are calibrated for certain types of light. Whenever an image is shot under different lighting conditions than this calibration (or color temperature), white does not appear white. If an image appears reddish it is referred to as “warm”, while bluish images are usually called “cool”.
Having a tint to your photos is not always a bad thing. Many photographers like to use warm images for landscapes and portraits. Cool tints can create wonderful images as well. The trick is to make sure that your color tints are deliberate. In order to use white balance to your advantage you should understand what light creates what tint.
In studying color temperature we learned how light color is measured by its temperature. Now we need to see what light creates what temperatures/tints.
White Balance Changes as Light Sources Change
Flame – Yellow to Orange
Incandescent Lighting (your house light bulbs) – Yellow
Sunrise/Sunset – Orange/Red to Yellow
Midday – White
Flash – White
Moonlight – Blue to Faint Yellow
Cloudy Sky – Blue
Overall, red color tints are more flattering to skin tones than are bluish tints. Yellow tints can also tend to give a jaundiced appearance if mild and make the whole photo look like it was dipped in mustard if strong. Yellow is one of the most common unintended white balance mistakes in photography. Also, it bears noting the camera phones have particular problems with blue under artificial lighting. This was the cause of the blue dress/gold dress Internet fight a while back (it was blue by the way).
In order to control color tint/white balance, photographers several tricks. Film photographers use specially calibrated film and/or filters to adjust white balance in their images as they are shot without the need for editing during processing. Digital photographers can set the white balance controls in their camera based on the shooting situation. Most digital cameras have white balance presets and many also have custom white balance settings so finer adjustments to the lighting situation can be made. Grey cards made for photographers are often used with this process to ensure the camera gets a clean reading on the situation. There are also special filters made for the camera to set custom white balance while shooting through the filter towards the light source. Some adjustment to color balance can also be made in a traditional darkroom or by using photo editing software. However, after shot adjustments can be more problematic and some white balance errors may be nearly impossible to correct in post processing.