Aperture and Depth of Field (DOF)

What is Aperture?

Well, aperture is the opening and closing of a device in your camera's lens called a 'diaphram' (it works very simillar to an iris of the human eye). This action determines how much light is being let into the camera' image sensor and also your image's 'depth of field'.

Aperture is measured and represented using 'f numbers'. f numbers, aperture and how they work may be quite daunting at first but when understood will help you improve your 'photographers eye' when picturing how you want you picture to look.

When taking a photograph; the higher your f number, the smaller the opening in your lens and the more of your image is in focus.
The smaller your f number, the wider the opening in your lens and the shallower your depth of field

Also in addition to DOF; the wider your openning, the more light your letting hit your camera's image sensor and the smaller your openning the less.

Here some examples showing Depth of Field and the amount of light being let into your image sensor:

f/5.3

f/5.6

 



Low f numbers with a wide aperture openning is often used in portrait photography, nature photography and others when you want to make a certain something or someone the main focus of your picture.
High f number with a small aperture openning is often used in landscape photography and when you'd like for most or everything in your picuture in focus.