How to Use Automatic Exposure on Your Digital Camera
Most digital cameras offer an autoexposure mode, sometimes called programmed autoexposure. This feature does just what its name implies: The camera reads the light in the scene and then sets the exposure automatically. To use your camera’s autoexposure:
Select the autoexposure metering mode you want to use.
You can find your options in your camera’s menu. Check out your camera’s documentation for the specifics.
Matrix metering (usually the default setting) divides the frame into a grid (matrix) and analyzes the light at many different points on the grid. The camera then chooses an exposure that best captures both shadowed and brightly lit portions of the scene. When using center-weighted metering, the camera measures assigns a greater importance to the center of the frame. With spot metering, the camera measures the light only at the center of the frame.
Frame your subject in the viewfinder or monitor.
You need a steady hand (or a tripod) because you have to hold this frame for a few moments.
Press the shutter button halfway and hold it there.
The camera analyzes the scene and sets the exposure, then it signals you — usually with a light near the viewfinder or with a beep.
Press the shutter button the rest of the way.
This takes the picture!