Camera Aperture Basics

If you're new to photography, then you've probably noticed that photography has a language all to its own. One of those confusing photographic terms is camera aperture so here is a breakdown of what aperture is, how it works and why it's important.

What is Camera Aperture?

In simple terms, aperture is the opening in your lens that lets light come into contact with your film (or digital sensors). You can change the opening using your camera's F stop or if you have a digital camera you can adjust it manually using your camera's settings. Some digital cameras even have a fixed aperture mode that lets you pick the aperture and the camera automatically figures out the other settings.

Aperture is measured in "F" numbers and is usually represented on your camera in abbreviations such as F8, F/8 or some variation in between. As the value of the F goes up, the amount of light allowed into the camera goes down. For example, an F value of 1/4 is a wide open aperture while 1/22 is considered as closed as possible.

What Does Aperture Do?

Camera aperture can have a significant impact on the look of your final images. With a closed aperture it lets in very little light into the camera which will give you the chance to expose your image for a longer period of time. Changing the F value is an effective way to use longer exposures and slower shutter speeds without overexposing your picture.

In addition, your aperture lets you respond on the spot to changes in lighting conditions. If you're photographing in bright light, a high F value (closed aperture) will give you the chance to use a slower shutter speed. But when photographing in a low light environment, you should open up the aperture to a very low F value to get the most flexibility when taking the picture.

Why Should I use Aperture?

Although you can change the aperture any time, it's not something that you have to change. With many SLRs the camera automatically adjusts the aperture making it easy not to worry about. But when manually adjusting the camera aperture you can directly change the image's depth of field. An open aperture will show very little depth of field (subjects that are near the camera will be very clear while the rest is very blurry), while a closed aperture will make your photographs seem more detailed.

Knowing when and how to adjust your aperture is a powerful tool in any photographer's bag of tricks. One way to see how aperture will affect your images is to take every picture twice - once with a low F value and once with a high one. Aperture is an amazing way to expand your creativity with the turn of a dial.