The Canon EOS Digital Rebel XS/1000D Companion

Using Priority Modes to Control Exposure

While the Exposure Compensation and Program Shift controls are both great ways to control exposure, there will be times when you'll want more direct control. Shutter and Aperture Priority let you select specific shutter speeds or apertures and leave the camera on those settings. So, for example, if you're shooting landscapes and know that you're going to want a deep depth of field all day long, you can set the camera on Aperture Priority, dial in f/11, and be assured that every shot will be taken with that aperture.

Or, if you're shooting a sporting event and know that you want lots of motion-stopping power, you can select Shutter Priority and set the shutter speed to something quick, like 1/1000th of a second.

Aperture Priority

To use Aperture Priority, set the XS's Mode dial to Av. In Aperture Priority mode, you select the aperture you want, and the camera automatically chooses an appropriate shutter speed, based on its metering.

In Aperture Priority mode, the rear LCD will display the current aperture setting in a gray box, with arrows on both sides to indicate that you can change this parameter. Turn the Main dial to change the aperture. When you half-press the shutter to meter, the camera will display the shutter speed that it has chosen.

Different lenses have different aperture ranges, and with a zoom lens, the wide end of the aperture range is often variable. For example, on the 18–55mm lens that Canon bundles with the XS, the wide end ...