The smaller the f-stop, the larger the aperture.
They run from f/1.4 (largest opening and most light let through) to f/32 (smallest opening and least light coming through). Most cameras start at f/2.8 or f/4.
The maximum aperture on your camera is usually written on the edge of the lens. Often, it is displayed without the f-number. For instance, when the maximum aperture is 2.8, it may appear as ‘1:2.8’. This signals that the lens can maintain the maximum aperture of f/2.8 throughout the full zoom range.
F-stops don’t run in fixed numbers – instead, they follow this pattern:
F-stops with the largest opening
f/1.4 – lets in most light but only included on professional or semi-professional cameras
f/2.0 – again, most mainstream cameras don’t start at this level
f/2.8 – often the lowest f-stop on most cameras and useful for low light conditions
f/4.0 – a good choice for travel and nature photography
f/5.6 – the middle ground, good for photos of cities, buildings and landscapes – where there’s no single point of focus
f/8.0 – at this level you start to notice changes in depth of field with added background blur
f/11.0 – the size aperture starts to provide a nice depth of field, and can be used for macro photography
f/16.0 – the smallest aperture on many cameras
f/22.0 – only go this small if you are more experienced, as sharpness levels can start to suffer
F-stops with the smallest opening.
As you go down the chart, each f-stop lets in half as much light. For example, the f/8.0 setting allows in half the light of f/5.6. These numbers are essentially fractions. So, an f/8.0 is an eighth, while f/2.0 is half. Thinking in these terms can help get your head around why the larger numbers mean smaller apertures – eighths are smaller than half.