Metering

A metering sensor.
This sensor is located inside the camera, where it measures the brightness of the subject when exposed to light.

Metering is used to measure the brightness of the subject. The camera adjusts shutter speed and aperture for optimal exposure according to the brightness of the subject, which is measured using the camera’s built-in metering sensor. The camera does not simply measure the overall brightness of the frame, but divides the frame into multiple areas. The metering mode determines which areas of the frame are used by the camera to measure subject brightness and how the camera sets exposure. Normally the camera uses matrix metering, in which it divides a wide area of the frame into multiple segments and sets exposure based on a variety of information, including subject brightness and color. You can also choose center-weighted metering (in which the camera assigns the greatest weight to the center of the frame) and spot metering (in which the camera meters the area around the selected focus point).

Choosing a metering method according to the scene and your creative intent allows you to achieve results that better mirror your artistic vision.

Red grid represents metering segments. Actual segments not shown.

Matrix metering ensures a balance between light and dark areas.

Center-weighted Metering

Red circle represents center metering area.

Exposure is set correctly for the center of the frame.

Spot Metering

Red circle represents spot metering area.

Exposure is set correctly for the portrait subject at the selected focus point.

Sample Camera Displays

D5000 information display

Metering:
Metering is displayed as shown below.
Matrix
Center-weighted
Spot