One of the most basic concepts in photography is also one of the easiest to understand. Today we're going to talk about white balance and how it affects your pictures. Understanding white balance will help your picture taking whether you've got a point and shoot or a DSLR. White balance is so easy to figure out, that you don't even need a camera to see examples in action.
Lets start without your camera. Find something in the room you're sitting that is either white or a neutral grey color. Now think about the color of light that is reflecting off of that object from the available light source in the room. Do you have normal, everyday tungsten light bulbs in a light fixture giving off light? Or do you have fluorescent tubes above you in an office building? Each source of light gives off a different color of light. You may not think about it normally, but once you start searching for it, you'll notice the differences are quite striking. The color of light from your light source is important to see because it actually affects the color your camera THINKS the object is. Your brain knows that your MacBook Pro is grey even when a red light is shining on it but a camera doesn't know what a MacBook Pro is and doesn't have a brain to interpret the object.
Digital cameras allow you to tell the camera what lighting conditions you are shooting in. Most will have settings for cloudy days, shade, sunlight, tungsten light and fluorescent light. In addition they'll also let you set a custom white balance. In the photo above, the boat was sitting in the shade which meant a lot of bluish light was falling on it. The camera didn't see white but instead saw blue. The photo that was produced turned out too blue. I corrected this later in post-processing but what I should have done was read the light my subject was in and adjusted my cameras settings before taking the picture.
Luckily, if you never want to deal with this, you don't have to! There is almost always an "Auto" setting which tells the camera to figure out the lighting conditions by itself. Usually, auto will be just fine to provide the correct white balance to a shot but sometimes it can get tricked. If you aren't comfortable playing with your white balance settings, leave it on "Auto." If you encounter a situation where "Auto" gets it wrong, I hope this quick lesson helps you take advantage of the other white balance settings to get the photograph you want.