Aperture Setting

by Tanya Puntti

How to use your cameras Aperture Setting to control depth of field

The Aperture setting is used to control how much of the subject or scenery is in focus. For example, when photographing a landscape you might want to have everything from the foreground to the background in nice sharp focus. On the other hand, when photographing friends and family, you might want a nice smooth blurred background, so the main subject stands out better.

One of the best ways to control this depth of field, is to use the camera’s Aperture Priority mode. If you look on your cameras mode dial, you should see the letters AV or A, depending on your model. If you can’t see it, check your User Manual for Aperture Priority.

On your display screen, the Aperture resembles an F number (if you own an entry level SLR). Some models may just display the number. Common F stop numbers or Aperture as it’s known, could range from F1.2 to F22 and beyond. How low or high the Aperture number goes, is determined by your lens. All lenses offer different Apertures.

Important things to know about Aperture

1. The higher the Aperture F number, the more in focus. Therefore if you want to photograph a landscape where everything is in focus, use an F number of 11 or higher. Higher Aperture numbers also require more natural light. Perfect for landscapes and outdoor photography.

2. The lower the Aperture F number, the less in focus. If you don’t need everything in the image to be in sharp focus, change the Aperture to a low F number, for example F2.8 or F4.7 etc. Low Aperture numbers are also useful for indoor shots, or situations with low natural lighting.

Aperture Settings for specific situations

1. Landscapes

Use a wide angle lens with a focal length of say anywhere between 17 and 24mm. Set Aperture to F11 to get everything in focus. Then focus 1/3 of the way into the scene before taking the shot.

2. Portraits or closeup photography with the background out of focus

For portraits change the lens focal length to any range between 50 and 100mm. Set the Aperture to a low number, for example F4.

Position the person so there is as much space between them and the nearest background as possible. For instance, don’t have them standing up against a wall as that defeats the purpose. Hence the wall will be in the same focal range as the person.

When you take the shot, stand as close to the person as you can, yet still be able to focus the camera. Follow these steps and you should get a nice blurred background.

Note: This information isn’t fully reliable for photographers using dedicated macro lenses. Such lenses will still throw much of the scenery out of focus, even with an Aperture setting of F11. I’ll talk about this style of photography in another section.

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