In this lesson: Discover how to optimize overall exposure by selecting the appropriate metering mode for a scene

Using your camera’s metering modes allows you to change the image exposure with greater precision and take control over how your image looks with regard to highlights and shadows.

The metering mode tells the camera what areas of the scene should have the highest priority in the context of correct exposure. To determine the overall exposure, your camera’s exposure system will attempt to render these areas such that middle gray tones are reproduced accurately. Additionally, the meter helps you determine the correct aperture and shutter speed depending on the amount of reflected light it measures in the scene. This is a critical point – the meter works off reflected light, not actual light, so it can sometimes be tricked.

For example, when photographing a snowy scene under overcast skies, your camera meter will often be tricked into thinking the scene is much brighter than it is because of the light being reflected off of the snow. Because it thinks the scene is brighter than it is, the camera will produce images that look flat, with snow that might appear gray, as is the case in the sample image of the boat in the fjord.

As lighting conditions change from scene to scene, the mode you select can have great impact on the results. For example, if you take a photo of a blue sky, the meter will have no trouble accurately gauging the light because only one value is present. However, adding in clouds or the sun will make the situation more complicated – the camera now has to determine the correct exposure based on its evaluation of the lighting of the sky, the clouds, and the sun.

There are several common metering modes.

Spot Metering

With spot metering, the camera only evaluates a very small surface area of the scene (between 1-5% of the viewfinder area). Dealing with such a small area to take a reading means that you have pinpoint control over the exposure of the image. Increasing your level of control is that many camera systems allow you to choose which autofocus point to use to get the meter reading.

Best usage: Spot metering is most useful for gathering detailed exposure information for one specific subject, like a bird perched on a limb or high contrast scenes in which the subject is a different light or color value than its surroundings, such as the man in the black and white sample portrait.

Center-Weighted Metering

In this metering method, the camera’s light meter centrally focuses on 60 to 80 percent of the central part of the viewfinder, with the balance feathered away from the center. One advantage of this method is that it averages a large area of the scene to be exposed without bias towards one small element, making it an ideal choice for images in which the subject is in the middle of the frame and the background is either very dark or very bright, as in the sample portrait of the man in a gray t-shirt. A disadvantage is that you cannot select which autofocus point is used to get the meter reading.

Best usage: Center-weighted metering is ideal for close-up portraits and for images in which backlighting is an issue.

Matrix Metering

For many DSLR and point and shoot cameras, this is the default meter setting. In this mode, the camera measures, combines, and calculates several areas in the scene to create a balanced exposure for the entire image. While some cameras use as few as 10 points, others may use thousands in one matrix. Essentially, your camera intelligently evaluates the whole scene, takes bright and dark areas into account, and then adjusts the contrast to get a final image that is well-exposed throughout, like in the sample image of the rock formations and pond.

Best usage: Matrix metering is best for scenes in which there is a large area of brightness or darkness. In the sample image of the landscape, multi-zone metering would take readings from the bright sky in the background, the darker areas of rocks in the midground, and the brighter areas of grasses in the foreground to get an all around good exposure.

Challenge Activity

In this activity, you will use two different scenes, and capture photos using the three primary metering modes without adjusting the camera position or zoom level. Once the images are taken, note the differences in overall exposure.

Step 1: Set your camera on a tripod to compose a scene with a subject that falls in its middle, with a relatively wide margin around the main subject.

Step 2: Take a photo using each of the metering modes your camera offers, using the same framing for each shot. Examine each resulting image. Note how the overall image exposure changes based on the mode you set.

Step 3: Set up your camera again, this time with a subject situated in the far right side of a higher contrast scene as in the sample image of the woman in the white dress.

Step 4: Without changing the framing, shoot the scene using each metering mode, as above.

Step 5: Note the differences in exposure and which modes are most appropriate for this type of scene.