Figuring out your aperture is important to learn in tandem with shutter speed. If you are unsure of aperture, visit the photography tutorials “Aperture Setting” and “Aperture F Number“. By going through these tutorials we will be able to focus purely on changing the setting to best fit your photography needs for each picture you take.
Check your camera and see what mode it is set. Switch the dial to the “M” or the manual mode. Next, find the aperture button and press it to begin changing the aperture setting. It should have the marking of “Av +/-” near it. Then rotate your command dial and watch on your status screen for the number change of the aperture number.
The shortcut for the aperture priority mode is shown as either “A” or “Av”.
As a side note, the aperture is what is telling the camera how much light to bring into the camera. Use a large aperture for low lighting and a small aperture for deeper depth of field. The larger the aperture setting number the smaller the hold will be that lets in the light.