Aperture and other photo basics can induce yawns in the most eager of new shutterbugs, but once these basics are understood, the rest of photography comes easily into focus. Aperture, ISO and shutter speed are all important terms to know, whether you have a point-and-shoot or a professional camera. This article explains the basics of aperture and provides tips on how to use it to take better pictures that you’ll be proud to display on your wall in a hanging picture frame.
To best understand aperture, consider how the irises of your eyes widen and narrow to allow more or less light into the pupil. Like your irises, the camera’s lens diaphragm widens and narrows to let in more or less light. Thus the aperture determines the exposure of the picture, that is how bright or dark it is. The aperture also has another important function which we’ll look at shortly.
“Aperture” refers to the size of this opening and is measured in F stops. The smaller the F stop, the wider the aperture. This is why it can be confusing. Actually the F stop numbers represent ratios, which is why the larger the F stop number, the smaller the aperture.
In addition to controlling light, aperture also controls depth of field. To better understand this, make a fist and hold it in front of your eye. Now gradually open your hand. See how the focus changes as you open your hand? Sure you can see more through the larger opening, but notice how when the opening in your fist was small, everything that you could see was equally in focus? Try it again, and notice how when you open your fist, the object closest to you will come into sharp focus while objects farther away will be out of focus. This is how aperture determines depth of field, that is how much of a photograph is focused.
If you are taking pictures in Auto Focus (AF), the camera will attempt to focus on what it sees as the main subject, but often it may not be what you want.
For this reason, many cameras have an Aperture Priority setting to help eliminate this problem. This allows you to set the aperture and then it automatically adjusts the shutter speed to compensate for the larger or smaller aperture. For example, if you set the aperture for a landscape, it narrows it and therefore lets in less light. The camera would automatically lengthen the time the shutter stays open so that your photo isn’t underexposed (too dark). Aperture Priority isn’t perfect, but generally this how it works.
Now if you have an SLR and are taking pictures in manual mode, you can adjust the shutter speeds and aperture separately.
Most will have a camera with preset modes such as landscape, sports or portrait. When the mode is set for landscape, the aperture automatically narrows so everything will be brought into focus. At the same time, the shutter speed automatically slows down, leaving the shutter open longer to offset the smaller amount of light coming through the lens diaphragm.
When you switch to portrait mode and focus on someone in front of you with the landscape in the background, the camera will make your subject in focus and make them stand out from the background. And it will speed up the shutter speed so the picture isn’t overexposed by the additional light allowed in with the larger aperture.
Remember: the smaller the aperture, the greater the F stop number (because it represents a ratio not a whole number) and the greater the depth of field.
Understanding photo basics like aperture is super important for using manual settings or aperture priority but also helps those using preset modes as well. Here are three preset modes you should better understand:
- Portrait: How much the background blurs when using this mode depends on your camera and the distance between your subject and background – a minimum of 10 feet works best. This mode can be used for any subject you want to bring into focus while taking the background out of focus.
- Landscape (also called “infinity” on some cameras) is the mode represented by a mountain peak or a figure 8. You can use this for anything where you want everything in the picture to be in focus, such as seascapes, cityscapes or your garden. And for shots of breathtaking vistas, try framing them in a panoramic picture frame to make your images really stand out.
- Macro: This mode, often depicted by a tulip opens the camera’s aperture extra wide so you can take super close ups. Depending upon your camera, you should be able to get anywhere between an inch to a foot of your subject. When preparing to take photos outdoors of items like flowers, remember that even the smallest petal movement can cause the image to be blurry because of the slower shutter speed. Also remember to focus on the part of the subject that you want most in focus, whether it be a butterfly’s wing or a caterpillar’s eyes.
Just applying this knowledge can help you produce some beautiful photographs that you’ll be proud to display in a gallery picture frame on the wall.