Today's cameras are truly incredible pieces of automation and technology. IN the push of a button they determine exposure and capture those special moments in life. Unfortunately, technology is not perfect. Your digital camera will make a judgment on exposure and color balance when it takes the photo. That judgment is based upon a set of parameters programmed into the camera by the manufacturer who assumed an average of color and light.

While this approach will often yield acceptable images it is not foolproof. You need to be smarter than the camera and be prepared to use your "exposure compensation" camera adjustment to tell the camera to adjust what it wants to do when taking a photograph. Exposure compensation is a valuable tool for adjusting and finding the right exposure.

Digital cameras often have problems creating the correct exposure when the subject lacks a good range of extreme brightness or darkness.

The black kitty pictured above illustrates this problem. The camera expects all the lights and darks to average to an 18% gray. As a result it wanted to lighten the picture and the result was the loss the the rich blacks of the cat's fur.

You will see the same problem when the subject contains a large amount of white. For example, the snow-covered landscape pictured below shows the camera's software telling it to move the scene closer to the 18% gray. that it expects an average scene to have. In this scenario the white areas tend to become grayish because the camera has intentionally underexposed the image to counter the overwhelming brightness. Many digital cameras have settings to overcome these situations. (See Camera Modes)

 

This example also demonstrates a similar problem with the auto white balance setting on cameras. This will be discussed in a later article.


When a camera over or underexposes an image important information about the image is lost. This loss of information will become more apparent the larger the printed photograph. Before you ask, PHOTOSHOP will not fix the problem. As good as the printed image may look to you, it would look better if the image had been photographed correctly.

To record these details, you will need to correct the exposure by selecting a better exposure setting. This is accessed through the camera's exposure compensation function. Look up "Exposure Compensation" in your camera manual to know where to access this setting.

The science behind these values is not as important as understanding their use. Simply put, if the scene is too bright on the screen use the compensation to reduce the exposure by using a negative value. If it is too bright, use minus settings on the exposure compensation to darken the setting.

What this means that when you walk in the snow or on a beach you will likely tell your camera to overexpose the scene. The darker scenario will more often occur when you are taking pictures of dark subjects, or when your subject has a very dark or distant dark background. In this scenario, you will want to tell the camera to underexpose.

Light will vary from scene to scene. Understanding exposure compensation is an important part of improving your digital photography ability. Beyond just situations with either extreme brightness or darkness, it is important to note that cameras may also tend to expose incorrectly when faced with backlit conditions or locations where one area may be in the shade and the other is in the sunlight. Once you have mastered finding and accessing this setting you will learn when to make adjustments before taking the photograph.

Additional Reading: