Aperture describes the size of the opening in a lens. As a way to control the look of the image, adjusting the aperture directly affects the depth of field. The larger aperture settings, like f/2.8, have a shallow depth of field and render the rest of the image with a blurred quality.

In this blog, I show you how much the aperture affects the look of the image. All three shots were taken without moving the tripod to illustrate the difference.

This first image was shot with a f/2.8 aperture, the largest available on this lens. As you can see, the background is very blurry. This is due to the shallow depth of field.

I set the aperture in this second shot to f/8. The background is more well defined and the separation between the subject and the background is less pronounced.

In this final image, I set the aperture to f/22. The background is more in focus and the subject is less well defined. I hope this helps to clarify what the aperture setting does to the image. Which one do you like best for this photo?