What is Aperture

Aperture refers to the opening of a lens's diaphragm through which light passes. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. The lower f/stops give more exposure because they represent the larger apertures, while the higher f/stops give less exposure because they represent smaller apertures.

 What is the depth of field?

Depth of field is the sharpness in front of and behind the object on which the lens is focused on. This zone will vary from photo to photo. Some images may have very small zones of focus which is called shallow depth of field. Others may have a very large zone of focus which is called deep depth of field. Three main factors that will affect how you control the depth of field of your images are, aperture (f-stop), distance from the subject to the camera, and focal length of the lens on your camera.

How does Aperture Affects Depth of Field?

Depth of field is the sharpness in front of and behind the object on which the lens is focused on.

The lower the f/stop—the larger the opening in the lens—the less depth of field—the blurrier the background.

The higher the f/stop—the smaller the opening in the lens—the greater the depth of field—the sharper the background.

ISO is the level of sensitivity of your camera to available light

High ISO (eg ISO 800) = More sensitive to light    

Low ISO (eg ISO 100) = Less sensitive to light