* Aperture is also called the "f-stop."
* Aperture controls the depth of field (how blurry the background is).
* Aperture also controls light that is let in through the lens.
* A large aperture has a large opening and a small number.
* Large apertures create a shallow depth of field and let a lot of light into the camera.
* A small aperture has a small opening and a large number.
* Small aperture creates a deep depth of field and lets very little light into the camera.