Controlling the aperture is an advanced technique which allows you to control the width of the lens opening (like the iris of an eye), allowing for more direct control over how much light enters the camera, and is normally referred to as an ‘F-stop’ or ‘aperture number’ such as F2.8 or F8 (a higher number refers to a smaller aperture opening, which means it is letting in less light, and a smaller number refers to a larger aperture opening – in this case, F refers to the focal length of the lens). A smaller aperture number allows you to use a shorter shutter speed (which makes it better for fast action shots), while a larger aperture allows you to use a longer shutter when there is bright light (for example, capturing the motion of a waterfall on a sunny day). Controlling the aperture also affects the depth of field within the photo (which refers to how much of the photo is in focus at the same time). For example, with landscape photography, you could use a small aperature to get a greater depth of field and have the whole scene in focus to see all the details, however with portrait or macro photography, you can use a larger aperture to get a shallow depth of field and isolate/highlight the subject by forcing the rest of the photo out of focus (DOF is also affected by focal length – the longer the focal length the less DOF, so because most smaller compact cameras have shorter focal lengths, it can be difficult for them to achieve a shallow DOF).