One of the most necessary but oftentimes least understood part of photography is Aperture. The size of the aperture, or f/stop, of a lens determines how much of your photograph is in focus. When you hear someone talk about f/stop, they are referring to aperture; the terms are often used interchangeably. The f/stop on a lens range from 1.4 to 22 or higher.
f/ 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32 are considered full stops. All cameras have these numbers but you’ll notice that you have way more numbers. If you have a Canon camera generally they incorporate third stops like 5.6, 6.3, 7.1, 8 where Nikon uses half stops. All this to say you will always see the full f/stops consecutively though they may start at f/5.6 and may only go to f/22.
f/stops can be confusing at first. The f/stop numbers refer to how open or closed the aperture on the lens is. f/1.4 would be a wide-open aperture on most lenses, whereas f/22 would be a virtually closed aperture. The WIDER the aperture, the more light that comes through the camera the LESS of your photo will be in focus. So the SMALLER the aperture, the less light allowed the MORE of your image will be in focus.
I have discussed Depth of Field in an earlier post. The reason I mention it here is that your f/stop is part of what controls the focus depth as you can see from the illustration above.
This one is a little harder to get but with practice it will come.