What is Aperture?
Aperture is the thing in the camera lens that you can shrink and enlarge to control the Depth of Field. The bigger the aperture opening, the less depth of field. The smaller the aperture opening, the more depth of field.


The Aperture is controlled by using the dial on the top of the camera when in Aperture Mode (Av)

What is Depth of Field?
Depth of Field, put simply, is the range of the camera. It determines how clear or blurry the background or an object further away is.
The less depth of field, the blurrier the background. The more depth of field, the clearer the background.
Low depth of field: High depth of field:

As you may have noticed by now, the unit to measure Depth of Field is f/number. The higher the number, the smaller the Aperture gap, the higher the Depth of Field.
With this knowledge, you can take advantage of the Depth of Field to make different kinds of shots.
A few examples are:



