The aperture is the opening in a lens, formed by a series of blades. As the aperture setting is altered on the camera, these blades open and close to regulate the quantity of light. A large aperture lets more light in, so the sensor only needs to be exposed for a comparatively short time in order to record a picture. A smaller aperture reduces the amount of light let in, so the sensor will need to be exposed for longer. The aperture size is listed in f-numbers, and confusingly, the smallest f-numbers correspond with the biggest holes – an aperture of f/1.4 is much larger than an aperture of f/22, for instance. If makes more sense if you think about it in terms of fractions, as 1/4 is larger than 1/22.
f/32 – deep depth of field A large aperture gives a narrow band of sharpness, while a small aperture gives a relatively extensive one. However, a lens generally gives the sharpest results somewhere in the middle of its aperture range, which is often an aperture of f/8
f/4.5 – shallow depth of field