Similar to Shutter Priority, Aperture Priority is the other semi-automatic exposure mode. Here you’ll be able to preset the Aperture and let the camera pick a shutter speed to go along with it. The big letter ‘A’ on your exposure dial is Aperture Priority. Again, you Canon users will be looking for something different. Canon uses ‘Av’ for Aperture Value.

By controlling the aperture you’ll be controlling the Depth Of Field (DOF) in your pictures. Remember that Depth Of Field is the amount in front of and behind your focus point that is also in focus. Smaller apertures give more DOF, larger apertures give less DOF.

The Portrait and Landscape scene modes do this for you “auto-magically”. Aperture Priority gives you more control and lets you use your brain instead of the cameras. By using Aperture Priority and precisely selecting your focus point you can maximize or minimize DOF. This is important in portrait photography, where you want the background to be blurred and not distract from your subject. It’s also useful in macro photography when you need to maximize your DOF.

As always, I encourage you to experiment the next time you’re out shooting. Try Aperture Priority. Use a couple different apertures on the same subject. Look at the images on your computer screen when you get home. Personally, I use Aperture Priority about 60-70% of the time. The rest of the time I shoot in Manual. We’ll get to that tomorrow.