F-Stop camera capability, also known as aperture range, is a key consideration when choosing a camera lens. Your choice of F-Stop has a dramatic effect on your final image. But what does F-Stop do on a camera lens, and how can it be used to create more interesting images?
Before you delve into the world of stops, it's important and useful to think about the type of photography you are looking to capture and the environment you will be working in. As you'll discover, F-Stops offer an array of creative possibilities.
Are you a budding portrait photographer? Will you be cave diving in Peru? Are you looking to capture sunrises or sunsets while travelling the world? Each of these instances will no doubt use F-Stops in differing ways. Let's dive into F-Stops, and which one you'll want to use for each type of photography.
Last updated: June 2025
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What does the F-stop do on a camera lens?
F-Stop is a value that represents the aperture setting of your lens. The aperture controls how much light is let into the camera. You will commonly see lenses with F-Stop as low (or as wide, meaning more light gets into your camera through the lens) as f/1.4–f/1.8, or as high (with a small opening, meaning less light) as f/22–f/32, with a host of options in between.
Why is it important to understand F-Stop?
F-Stops are used by photographers to control light based on external conditions. If there is less ambient light you can choose a lower F-Stop to let more light into your camera. Using F-Stops in conjunction with ISO ensures you have the clearest image possible. By contrast, if you are outside on a bright day, you risk over-exposure at the same stop. Having the ability to increase the F-Stop means you can lessen the amount of light coming into the camera to ensure an equally sharp image in different light situations.
F-Stop and depth of field
F-Stops also offer varying depths of field for your images, which can be used in a variety of creative ways. Using a larger aperture or smaller F-Stop, such as f/1.4–f/1.8, creates a shallow depth of field. This means subjects in the foreground stay in focus, but everything behind that point will be blurry. This blur effect is often called bokeh — a pleasing or aesthetic quality of out-of-focus blur in a photograph. This is particularly popular among portrait photographers as it draws the gaze to a central figure or object.
Take a look at some of the world's most recognised photos of people. You will find that they often are blurry in part of the image. The eyes and central features may be crisp but the background could appear much softer. F-Stops are responsible for creating this effect and is why many photographers opt for lenses that offer the lowest F-Stops possible.
A smaller aperture or larger F-Stop, such as f/16–f/32, is best for a greater depth of field, putting more objects in focus. Landscape photographers use this to capture more elements of a scene, so that objects that are close and in the distance are both in focus. In this instance, bushes or people in the foreground may appear as sharp as trees in the distance.
Master F-Stops and find your own photography style
F-Stops not only enable you to have manual control over the amount of light you allow into the camera, but the effects also afford photographers the ability to be creative and direct the viewer's gaze to particular areas of a photo. To really brush up on your photography skills, you can discover Ted's beginner's guide to basic camera settings.
Camera F-Stops Explained: The Complete F-Stop Scale
If you've ever wondered what all those numbers on your lens or camera screen actually mean, you're not alone. Camera f-stops explained simply: each f-stop number on the scale represents a specific aperture size, and moving from one stop to the next either doubles or halves the amount of light entering your camera. This is one of the most fundamental concepts in photography, yet it trips up beginners and intermediate shooters alike.
The standard f-stop scale runs as follows: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22. Here's the counterintuitive part — the smaller the f-stop number, the wider the aperture opening, and therefore the more light that enters the lens. A lens set to f/1.4 is letting in significantly more light than a lens set to f/16.
Each step along the scale is referred to as one "stop" of light. Moving from f/4 to f/5.6, for example, reduces the light by half. Moving from f/5.6 back to f/4 doubles the light. Understanding this relationship is critical because aperture doesn't work in isolation — it interacts directly with your shutter speed and ISO to form what photographers call the exposure triangle.
Modern cameras also allow you to shoot in one-third stop increments (e.g., f/3.2, f/3.5, f/4.5), giving you much finer control over exposure. However, the full-stop values listed above are the foundational reference points every photographer should commit to memory. Once you understand the scale, adjusting exposure on the fly becomes second nature — whether you're shooting a fast-moving subject indoors or capturing a sweeping landscape at golden hour.
Define F-Stop: The Photography Definition You Need to Know
Let's define f-stop clearly and precisely, because having a solid definition is the foundation for everything else in aperture-based photography.
F-stop definition: An f-stop (also written as f-number or focal ratio) is a dimensionless number that expresses the ratio of a lens's focal length to the diameter of the aperture opening. The formula is: f-stop = focal length ÷ aperture diameter. For example, a 50mm lens with an aperture opening of 25mm has an f-stop of f/2.
In plain terms, the f-stop tells you how open or closed the "iris" of your lens is at any given moment. Just like the pupil of a human eye dilates in darkness and contracts in bright light, a camera lens aperture widens at lower f-stop values to gather more light, and narrows at higher f-stop values to restrict it.
The "f" in f-stop stands for focal length — a reminder that the number is always relative to the lens you're using. This is why an f/2.8 aperture on a 24mm lens has a physically smaller opening than an f/2.8 aperture on a 200mm lens, even though both let in the same amount of light relative to their focal length.
Why does this definition matter practically? Because understanding what f-stop actually measures helps you make smarter decisions when comparing lenses. A lens described as having a "maximum aperture of f/1.8" is telling you it can open very wide — ideal for low-light shooting or achieving a blurred background. A lens with a maximum aperture of f/5.6 is more restricted in low light but may offer other advantages in sharpness or zoom range. Knowing the definition helps you read lens specifications with confidence.
Which Camera F-Stop Should You Use? A Guide by Photography Type
Understanding camera f-stops in theory is one thing — knowing which f-stop to use in a real-world shooting situation is where that knowledge becomes powerful. The right f-stop depends heavily on your subject, your environment, and the creative look you're going for. Here's a practical breakdown to help you choose the right setting every time.
Portrait Photography: f/1.4 – f/2.8
For portraits, most photographers reach for a wide aperture such as f/1.8 or f/2. This creates a shallow depth of field, keeping your subject's face sharp while blurring the background into a smooth, creamy bokeh. The result is a professional-looking separation between subject and background. Prime lenses with a maximum aperture of f/1.4 or f/1.8 are popular choices for portrait work for exactly this reason.
Landscape Photography: f/8 – f/16
Landscape photographers typically want everything in frame to be sharp — from the rocks in the foreground to the mountains on the horizon. A narrower aperture in the range of f/8 to f/11 achieves this by maximising depth of field. Many lenses also hit their optical "sweet spot" for sharpness somewhere in this range, making it doubly effective for detailed landscape shots.
Sports and Action Photography: f/2.8 – f/4
Shooting fast-moving subjects requires a faster shutter speed to freeze motion, which in turn demands more light. A wider aperture of f/2.8 to f/4 lets in enough light to support those faster shutter speeds without pushing your ISO too high and introducing grain. Many professional sports zoom lenses are designed with a constant maximum aperture of f/2.8 for this very reason.
Low-Light and Indoor Photography: f/1.4 – f/2.8
In dark environments — whether that's a dimly lit wedding reception, an underground cave, or a concert venue — you'll want to open your aperture as wide as possible. Lenses with a maximum aperture of f/1.4 or f/1.8 are invaluable here, allowing you to capture well-exposed images without resorting to excessively high ISO settings that degrade image quality.
Macro Photography: f/8 – f/16
Macro photography involves shooting at extremely close distances, where depth of field becomes razor-thin even at narrow apertures. Stopping down to f/8 or beyond helps ensure more of your subject — a flower petal, an insect, a watch mechanism — stays in focus, though you may need a tripod and additional lighting to compensate for the reduced light.