Aperture

Aperture controls the depth of field. The larger the aperture number, the smaller the depth of field.This means that less of your image is in focus, only subjects closer to the camera lens are in focus as your depth of field is shallower. The aperture is controlled by adjusting the F. number, small F. numbers such as F.3.5 will give you a shallow depth of field while higher F. numbers such as F.22 will give you a broader depth of field. To control the aperture you must set your camera to aperture priority mode. To use small apertures with F. numbers of F.22 you must have good lighting conditions and the shutter speed will be longer. This is because the smaller the aperture the smaller the hole behind the camera lens so less light is let into the image. Therefore, the shutter speed is increased to make up for this and sometimes you must use a tripod as longer shutter speeds allow camera shake to be seen in the final image.

Thin depth of field

Medium depth of field

Broad depth of field