What is F-Stop and How Does It Work

Those who are just starting to learn about photography or attempting to learn more often hear the words ISO, exposure, f-number, and shutter speeds.

Learning about these terms and how they relate to each other can be daunting. Our guide is here to help give more clarity on one of these terms—f-stops.

F-stops can appear to be mathematical and confusing, but they are easy to understand and manage once you realize how to affect your photography.

Let’s take a look at what f-stops are and how that is significant to your work as a photographer.

What is Aperture and why is it important?

You can think of aperture as an opening. An aperture refers to a hole in the camera lens that occurs when the shutter opens on the camera.

Blades are placed around the camera lens. These blades form a circular ring around the lens. Therefore, the aperture is a circular shape.

The hole in the middle of the camera lets light pass through the camera and allows the light to hit the sensor housed within the camera.

The photographer can control and change the aperture size and setting. The aperture can usually be changed by turning or twisting the rings around the aperture. The twisting makes the aperture wider (bigger) or smaller (narrower).

Various lenses allow for different aperture sizes. The size of the lens can affect the size of the aperture and the possible diameter of the aperture.

A change in aperture size changes the amount of light allowed to pass through the camera to the sensor.

As the aperture becomes smaller, less light can pass through.

The aperture is important because it controls the amount of light that passes through the camera, which changes how your photos develop.

The aperture, along with the f-stop, influences the quality of your photos. The aperture affects the clarity of your photos.

What are F-Stops?

The f-stop refers to the camera setting that points to the aperture of the lens. The “f” in f-stop refers to the focal length of the lens itself.

You can think of the f-stop as the diameter of the aperture or the size of the lens.

The f-stop is also referred to as the f-ratio, the f-number, and the focal ratio.

How do I use F-Stops?

There are two primary uses of f-stops—to control light and to change the clarity of photographs.

The f-stop allows or restricts light to pass through the camera. This means that you want to think about the amount of light you want or do not want to pass through the camera.

The f-stop adjusts the exposure of your photo, which can change the lightness or darkness of the photo.

The f-stop can also allow or changes in clarity, blurring, and focus. This is often thought of as the depth of field (DOF).

The depth of field is controlled by changing the f-stops of your camera.

The smaller your aperture (which is indicated by larger f-numbers), the greater your depth of field. This means more of your picture will be in focus, and there will be little to no blurring effects.

A wider aperture (indicated by a smaller f-number) will have more blurring to put a chosen subject in focus.

For instance, if you want to only focus on a subject in the foreground, you will need to adjust your camera to focus on the subject rather than focusing on the capture of the entire field of view.

Changing the f-stop can make a key difference in your photos, including the detail present in the photo and even the focus of the photo. Changing the f-stop can significantly change what a viewer sees in your photograph.

Why is the f-number used when measuring Aperature?

The f-number is a kind of mathematical principle that centers on your camera’s focus.

The f-number specifically refers to the focal length of your camera over the size of the aperture. Therefore, the f-number is a fraction.

Here is the equation:  [F-stop = focal length / diameter of aperature]

While this may seem complicated, there is a positive. Since this is an equation that takes your focal length and aperture into consideration, that means that the f-stop will always remain the same across cameras.

No matter the camera, the same f-number on one camera will amount to the same exposure on another camera using the same f-number.

If the ISO and the shutter speed are set to the same speed on both cameras (with different focal lengths), then the exposure will remain the same between the two cameras.

What does the “f” stand for in F-stop?

The “f” in f-stop stands for “focal length.” This indicates the size of your aperture.

What are the F-stop Value Sets?

The range of the F-stop values depends and changes with the lens being used. However, there are basic sets of f-numbers within a range.

There are full stops, ½ stops, and 1/3 stops.

Included below is the range of values for each category of stop–ranging from more light and less field of depth to less light and more field of depth.

Full Stops: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/65

Half Stops: f/1, f/1.2, f/1.4, f/1.7, f/2, f/2.4, f/2.8, 4/3.3, f/4, f/4.8, f/5.6, f/6.7, f/8, f/9.5, f/11, f/13, f/16, f/19, f/22

Third Stops: [f/1/, f/1.1, f/1.2, f/1.4, f.1.6], [f/1.8, f/2, f/2.2] [f/2.5, f/2.8, f/3.2,] [f/3.5, f/4/, f/4.5,] [f/5, f/5.6, f/6.3,] [f/7.1, f/8, f/9,] [f/10, f/11, f/13/,f/14, f/16, f/18,] [f/20,/f22, f/25], [f/29, f/32, f/36,] [f/40, f/45, f/51,] [f/57, f/64]

Smaller aperatures have higher f-numbers, such as f/22. On the other hand, wider and larger aperatures have lower f-numbers, such as f/2.

When do I need a big Aperature? When do I need a small Aperature?

The size aperture you need depends on the setting and your desired effect. Using an incorrect aperture can be detrimental to your photography.

Wider and larger lenses are great for focusing on a single subject in your photo, especially if you want to draw a subject in the foreground away from the background.

While wider lenses can isolate subjects in the photos, these photos tend to have a softer quality. This is referred to as spherical aberration.

Wider and bigger lenses can be difficult to manage in brighter scenes or settings. In these bright conditions, the camera’s shutter speed may be too slow to maintain correct exposure. Therefore, your photos may end up too bright.

On the other hand, smaller apertures can be difficult to manage because you need longer exposure times with smaller lenses.

If the aperture is open longer than the photo may show signs of the photographer shaking, therefore, tripod and stabilization devices are usually needed when using smaller ones.

What is the minimum size Aperature I should have?

Most people are concerned about the maximum size of their aperture. The minimum aperture is not very relevant because the differences between the f-numbers when reaching the smaller scale are negligible.

How can I adjust Aperature or F-Stops on my camera?

In most cases, you can change the aperture on a digital camera by using one of two common methods.

You can switch your camera to manual mode, which is often indicated on a top dial by the letter “M.” This setting takes you out of an automatic mode or other modes to give you complete control of the aperture, as well as the shutter speed.

Some cameras have a setting called Aperture priority mode. This is sometimes written as “A” or “AV.” This mode automatically changes the shutter speed as you adjust your aperture.

Other cameras can be adjusted through the digital display screen on the camera. You may also have a camera where you adjust the aperture on or through the lens itself.

Be sure to read about your camera and how to change the aperture or shutter speed before turning dials and pressing buttons.

On DSLR cameras, the f-stop number is often at the top-right side of the camera and usually shown under the image within the viewfinder itself.

What is the best F-number for different types of photography?

The best f-number truly depends on both your subject and what kind of photo you want to take. Knowing what speed of f-stop you need may take a little experimentation and practice.

However, here is a general guideline to help you choose the f-number for the kind of photograph you want to take:

-Nighttime Photography: f/1.8-f/2/8
-Sports Photography: f/2.8-f/6.3
-Portraits: f/2.8-f/5.6
-Landscapes: f/11-f/22

Since you need more exposure time when it comes to night scenes, you want to have a wider lens that allows more light to pass.

Sports photographers usually want to isolate the athlete from the environment, so you want a wider lens and a faster shutter speed to achieve this effect.

Utilizing the best f-stop in future photography

The f-stop may seem confusing at first, but our guide shows you that it is simply about the size of your aperture and how much light can pass through your camera.

You can begin to elevate the quality and content of your photography by experimenting and mastering the use of the f-stop. You can change the focus, color, field of depth, dimension, and character of your photos through manipulation of the f-stop.

You can begin to isolate subjects in your photos or give clarity to the subjects in your view. Our guide is a great first step to finding your footing with the f-stop.

Frequently Asked Questions

How are Apertures measured?

Apertures are measured in f-stops. This is the focal length over the diameter of the aperture.

What is the range of the F-stop?

F-stops range from f/1 (smallest) to f/64 (largest). The smaller numbers indicate a larger aperture while the larger numbers indicate a smaller aperture.

What is DOP?

DOP stands for Depth of Field. This is essentially the focus of the photograph.

A deep focus or deep depth of field means that both the background and foreground will be in focus.

A shallow depth of field means that only a small area or subject in the photograph is in focus. Everything else in the photo is blurred.

How does Aperture size affect the DOP?

In general, the larger apertures create a shallower depth of field. The smaller apertures create a deeper depth of field.

What is Bokeh and how do I achieve it?

Bokeh, which comes from the Japanese words meaning blur or haze is a kind of photograph that has a softer background that is blurry while there is a subject in focus.

Bokeh photography is achieved by having a quick lens. You want the lens to be fast, which means you need an f/2.8 aperture or faster.

To achieve Bokeh, use a wide lens, and a fast shutter speed.

What is the Aperture priority mode good for?

The A or AV mode is great when you want to control or manipulate the field of depth. In this setting, you can choose the aperture setting to match the depth of field you desire.

Once you set this aperture size, the camera selects a shutter speed to match your selection.

The AV mode not only saves you time, but it also gives you a higher chance of achieving your desired results within a shorter amount of time.

What does it mean when a Lens is fast?

Photographers have developed this slang or lingo that refers to some lenses as fast.

A fast lens refers to a lens’ maximum aperture. The lenses with the largest maximum apertures are called the fast lenses.

Fast lenses are often more expensive, but they can let in twice as much light into the camera. This also means they offer more stops.