I’ve been teaching beginning digital photography workshops here in
So what is white balance? There really is no such thing as white light. White is the result of mixing all of the different colors of the spectrum. However, these colors aren’t usually mixed evenly, so we describe white light as having different temperatures. If the light has more blue in it, we say it is cooler, if it has more red, we say it is warmer. For instance, typical indoor lighting is much warmer than sunlight. If your camera’s white balance is set for “daylight” your images will look very red when taken indoors.
One of the reasons this is a difficult concept for my students to grasp is because of the way our cameras see light differently than our eyes do. For instance, if you look at this newspaper under different lighting conditions (daylight, incandescent, or fluorescent) the paper always looks white. However, your camera might see the paper as blue or red. This is because your camera image sensor sees light in absolutes. It sees red, green, and blue light in terms of numerical quantities. Our eyes see light in much the same way, but only a fraction of what we see actually comes from our eyes.
The fact is much of what we “see” is actually from the way our brains interpret the data from our eyes. The reason that this newspaper looks white to you regardless of where you are reading it is because your brain has learned that newspapers are white, and makes an interpretation based on your experiences. Your camera’s “auto white balance” setting can try to accomplish this same result, and 75% of the time will yield acceptable results. However, the other 25% of the time when the light is the most interesting, the automatic settings on your camera will miss the mark. This is when it is best to use your manual white balance settings. For instance, in the accompanying photo of the
Becase space in the paper is limitted, each week I will add aditional examples and information to my blog.
Digital cameras have multiple settings for white balance. The most important and often used are:
AWB or auto white balance – This is what I usually have my camera set on. It works just fine about 75% of the time.
Daylight – Exactly what it says. This is for shooting outside, or to give a warmer look to indoor photos.
Tungsten or Incandescent – Used for shooting indoors under normal lights
Flourescent – Used for shooting under flourescent lights. Eliminates greenish cast.
Your camera might also have settings for cloudy, shade, or flash.
In this example, the camera’s white balance was set to “daylight” which made the flourescent lights in the image appear very green.
Although the green effect can seem interesting, the next example shows what happens when the camera’s auto white balance mode was set. Notice how the white’s appear much more neutral. An even more accurate color could have been acheived by manually setting the camera’s white balance to flourescent mode.
Auto white balance can help make an image appear more neutral, but that isn’t always a good thing. The following image was captured in auto mode. Notice how flat the image looks. This is becuase the camera is trying to make the very intense colors appear more neutral. The image on the right was made using “daylight” mode. Using daylight mode tricks the camera into thinking is is being used during mid day, and therefore makes the sunset appear very warm and more true the actual experience.