Understanding Color: Part 2, Light Sources and White Balance

We photographers depend on the presence and absence of light to create our images.

But all light is not the same.Every light source has an average color range. Moonlight is a different color than sunlight. Incandescent light bulbs are warmer than most fluorescent light bulbs. Light from a candle is significantly yellower than light from most LED flashlights, which are often kind of bluish.

You can respond to and control your relationship with the light by adjusting the White Balance of your camera. Selecting a correct White Balance will leave the neutrals neutral. In other words, the photo will look a lot like what you see with your own two eyes. This is usually our goal: match the white balance settings of our cameras to the color temperature that we really see in the world. To say that what you’ve photographed looks like what you see with your eyes, that the white balance is matched, is to say that the photo is ‘color accurate’ or 'color correct.'

If you haven’t set your White Balance controls for the lighting you’re using for your photo, then you may end up with neutral areas of a photo appearing too vivid or unusually colorful. This is often an accident, but you could adjust the White Balance for artistic effects… if the colors are more vivid than what you can see, then you must be being an expressive artist – same if they are highly desaturated, or mainly grayscale (which isn’t like what we see in the world but can be very beautiful). Selecting the right White Balance for your artistic needs is the first step towards being more artistic with your use of Light, and being able to select the kind of artistry that you’d like to be rather than making images by default of whatever automatic settings are used by your camera.

How light is defined: Light is defined by it’s Color Temperature. For example, bright daylight is defined as 5500k, whereas the flash of your camera may have a temperature of 5400k, an incandescent light bulb 3,000k, a Fluorescent light bulb at 4200k, a cloudy day might be 6,000k and in shade, perhaps 7,000k or even 8,000k if it’s foggy. The ‘k’ stands for the Kelvin Temperature Range (if you want to read all about using the Kelvin to measure color temperatures, black-body radiators, etc., then click here: http://en.wikipedia.org/wiki/Color_temperature). It used to be that you had to select a particular kind of film to match the color temperature, for example, using a Tungsten film if you had hot halogen lighting in the studio, or Fujichrome film if you wanted vivid outdoor action photos. Instead of having to swap out the film to match the lighting, today’s digital cameras have a button. The button alters a series of settings that you can use to match your White Balance with the lighting in the world around you.

In a Nikon digital SLR, there’s just a little button on the top of the camera, marked WB, and you can scroll through some settings easily.With many non-SLR cameras, you may find a menu screen full of 'scenes' such as Snow, Candle, Sunlight, Landscape, Portrait, Cloudy, etc. Each of these is likely changing the white balance to compensate for the typical color temperatures found in each kind of scene.

So here’s your mini-assignment: take a set of pictures of the same object or person, but using different white balance settings. It's easiest to see the differences if you use an object that is light in value. Then cut and paste the pictures to make a composition like this one:

Use the text tool so that to label what kind of light source you’re using, and then label each image for how you changed the white balance in your camera. As a result you now have a composite Reference Photo that you can rely on to compare and contrast with while you make images – do you need to make an image feel warmer, when using an indoors fluorescent light source? Then shift the white balance to Daylight or Flash. Do you need it cooler and more mysterious? Then shift the wb to Incandescent... and so on.

Label and submit your composite image to our shared Picasa album.