Choose your exposure mode before setting the aperture.
The aperture setting on a digital single-lens reflex camera in-part determines how your photos will turn out. Aperture, shutter speed and ISO -- also known as digital sensor sensitivity -- work together and balance one another to expose a photograph. When adjusting the aperture manually on your camera, you must also set the shutter speed and ISO, like a teeter-totter, to achieve a well-exposed photograph. Most DSLR cameras offer an aperture priority mode that allows the photographer to adjust the aperture and the camera automatically balances the shutter speed while the ISO stays set.
Instructions
1. Turn the digital camera's power button to "On."
2. Rotate the command dial on the top, left side of the camera to either the aperture priority mode -- noted as "A" or "Av" -- or the manual mode noted with an "M."
3. Locate the dial near the shutter button, on the top, right side of the camera, and rotate the dial to the left to lower the aperture number, or to the right to increase the aperture number.
4. Look through the camera's viewfinder at the shooting data or at an information panel near the camera's shutter button to view the aperture numbers you're selecting.
5. Stop the dial on the preferred aperture number. Press the shutter button lightly half-way down to save the setting and exit the aperture adjustment feature.
Tags: aperture number, shutter button, shutter speed, aperture priority, aperture priority mode