Light MetersIf you own a digital camera, understanding light meters should be important to you because your camera has a light meter built into it. More than likely your camera has several available light meters, and understanding the difference between them can often mean the difference between an okay picture and an outstanding one. Light meters are important because your camera uses the data from them to set the correct exposure for your picture.
You can easily find out which light meters are in your camera by either:
1. Consulting your owner's manual
2. Pressing the "function" or "menu" button on your camera. The function menu will list the available light meters and allow you to switch between them.
Chances are your camera has three light meters; evaluative (sometimes called "Multi Pattern" or "Matrix"), Center Weight Average and Spot.
Evaluative is by far the most frequently used meter among the trio. The evaluative light meter can handle just about any lighting situation and it will set an acceptable exposure just about every time. The evaluative light meter divides the image into multiple regions and metering is performed on each individual region. The camera judges the subject position and background brightness,and determines a well-balanced exposure. If you ever become confused as to which meter to use, set the camera to Evaluative. It is especially good at metering complex lighting conditions, images containing many shadows, or images with multiple and bright contrasting colors and hues.
Center Weight Average meters the image with priority given to the
center of the image. The camera determines the exposure based on the brightness of the subject near the center according to the shooting angle used by the camera. The camera arrives at a proper exposure by performing complex mathematical algorithms. (I bet you didn't know your camera is a math whiz, did you?). Use Center Weight Average metering when your subject is backlit (bright light shining behind the subject) or when the subject is surrounded by bright light.
Spot is a different breed of light meter altogether -maybe even a different animal. Because spot meters measure the light only on a specific area. Spot metering lets you adjust the exposure to the subject even when the subject is backlit or there is strong contrast between the subject and the background. When you select the spot meter, a small "+" or box will appear in your LCD monitor. Position the spot metering cross-hairs or box over your subject, and only the area appearing in front of the cross-hairs or inside the box will be metered.
Like I said, if you ever get confused, switch your camera over to the evaluative or multi-pattern light meter. It will work pretty well in any shooting condition. But I encourage you to experiment with your light meters. If you are not achieving an acceptable exposure, switch to a different light meter and try again. Choosing the correct light meter will greatly improve the quality of your photographs.