If you have any exposure to photography (*ahem* sorry), you've probably heard the word aperture. But do you understand what it actually is?

Aperture refers to the adjustable opening through which light travels through the lens to the film or chip on the camera which captures the picture. The larger the aperture the more light that hits the film or sensor to record the image and the shorter the exposure time needs to be. 

Aperture is controlled in the camera by the f-stop. The f-stop determines how large or small the aperture is. A small aperture has a high f-stop number - f22 is a small aperture, f2.8 is a large aperture. Each f-stop lets either twice as much or half as much light as the next aperture on the scale. 

Aperture affects the photograph in two ways:

  • Length of exposure time - a large aperture lets a lot of light through the lens quickly, which means the picture is properly exposed more quickly than it would if you used a smaller aperture. 
  • Depth of field - because the image is captured more quickly, the depth of field is shallower. This means that less of the photograph will be in focus than if you use a smaller aperture. 
Image created by CelinaTH and used under a Creative Commons license.

Image created by CelinaTH and used under a Creative Commons license.