Understanding Camera Aperture

Are you eagerly waiting to put your newly learned photography basics to work? Well, here’s another very important bit of knowledge to add to your repertoire. Learning aperture and other technical photography basics may not be as much fun as learning to take fantastic landscape pictures or going shopping, but once you understand these basics your photos will be in perfect focus. Get to know the terms aperture, shutter speed and ISO whether you have a point and shoot or a professional camera. This article explains what aperture is and how to use it for creating better photographs.

Aperture can best be understood by comparing it to the irises of your eyes. Just as the irises widen and narrow to allow more or less light into your pupil, so does the camera’s lens diaphragm. The size of the opening is the aperture and it determines the exposure of the picture, or how bright or dark it is.

Aperture is measured in F stops. The smaller the F stop, the wider the aperture. This can be confusing, but just remember that the F stop numbers represent ratios; thus, the larger the F stop number, the smaller the aperture.

A second function of aperture is it controls depth of field. The aperture determines depth of field or how much of your photograph is focused. A smaller aperture has a narrow focus so everything you see is equally focused, whereas a wider aperture allows you to see more but sharp focus will be on the closest object leaving objects further away out of focus.

With an SLR shooting in manual mode, you can separately adjust the aperture and shutter speeds, but a camera’s Auto Focus (AF) attempts to sense the main subject of the photograph, not always the photographic results you want.

To avoid incorrect focus many cameras have an Aperture Priority setting. Although not perfect, Aperture Priority lets you set the aperture so it automatically adjusts the shutter speed to compensate for the larger or smaller aperture. For example, if you set the aperture for a landscape, this narrows it, thus letting in less light. Your photo won’t be underexposed (too dark) because the camera automatically lengthens the time the shutter stays open.

With preset modes, such as portrait, landscape, sports, etc, the camera will adjust focus.
When the mode is set to landscape, the aperture automatically narrows to bring everything into focus and the shutter speed automatically slows, leaving the shutter open longer to compensate for the lessened amount of light coming through the diaphragm.

When you are in portrait mode focusing on a person in front of you with the landscape in the background, the camera will adjust so the person stands out more than the landscape. Shutter speed will increase so the picture isn't overexposed by the amount of light allowed in with the larger aperture.

Remember: The F stop number represents a ratio, not a whole number. For greater depth of field, the smaller the aperture, the greater the F stop number.

Photography basics like aperture can seem a daunting subject to grasp and not one you need to learn if you are not using a manual setting or Aperture Priority. But, take the time to understand aperture because it is also helpful when using preset modes, like these three:

• Macro Mode: Have you ever wondered what the tulip on your camera depicts? Well, this is it, and this is what it does. Macro opens the camera's aperture extra wide so that you can take extreme closeups without the blur caused by not enough focus. The extent of the close up depends on your camera, but you may be able to be anywhere within an inch to a foot of your subject. Remember to focus on the part of the subject that you want most in focus. And, keep in mind that the tiniest movement of your subject can cause blur due to the slower shutter speed.
• Landscape Mode: This mode is called "Infinity" on some cameras. Symbols depicting this mode are mountain peak or figure 8. Use this mode when you want everything in the picture to be in focus like landscapes, seascapes, city scapes or garden settings.
• Portrait Mode: Your camera, and distance between subject and background, determines how much the background blurs when using this mode. A minimum of 10 feet between your subject and background works best. Use this mode for any subject that you want to bring into focus while taking the background out of focus.

Once you understand Aperture basics you will be able to apply your knowledge and, with practice and patience, you will be producing and framing beautiful photographs you will be proud to share with others.