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What is Aperture in Photography?

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Bret Leon
18 January, 2023 • Updated 14 days ago
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Aperture is one of those terms that seems simple enough on the surface but actually has quite a lot of technical jargon behind it. In this article, we’ll go over what it really means, why it matters, and how photographers use it.

Aperture refers to the size of the opening inside the lens that lets light into the camera. The lens’s aperture mechanism is made up of a series of opaque “blades” known as diaphragms. Your camera sensor will be able to take in a greater quantity of light when the blades are wide open; as the blades continue to close, the amount of light that reaches your sensor will decrease.

The human pupil dilates or contracts in response to changes in the brightness of the surrounding light. Aperture works similarly, in that its opening widens or narrows in response to the intensity of the light entering it.

By adjusting the size of the blades, you can control the amount of light entering the camera. This controls the exposure of the photo. A larger hole allows more light to enter, resulting in brighter images. But too large of an opening will allow in unwanted light, causing overexposure.

Aperture also allows a photographer more creative freedom in deciding what parts of the image to sharply concentrate on and what parts to intentionally blur.

Related Post: What is ISO in Photography?

Aperture and f-stops

camera lens on the table

The aperture of your lens is displayed in f-numbers, the so-called f-stop (or focal-stop number). So why is it called a stop? Simply put: it’s an aperture setting that limits the light coming into the lens. It limits the brightness of an image by restricting the input pupil size. In other words, it stops the light.

In photography, apertures are measured using a precise system. These standards are used by all camera and lens manufacturers, therefore comparisons between brands are straightforward. F-stop numbers typically range from lesser values, such as f/2.8, all the way up to f/22 (or higher). As the f-stop number decreases, more light enters the camera.

Now, the aperture is reduced by a factor of half for every full stop. So going from f/2.8 to f/4 cuts the aperture in half. And going from f/4 to f/5.6 cuts the aperture in half again. When you first start learning about aperture and f-stops, it can be difficult to keep everything in order. But if you keep at it, you’ll soon find it comes easily.

Large vs Small Aperture

camera lens in hand

This is a crucial aspect of aperture that causes the most consternation among amateur photographers. Remember: apertures with lower numbers are wider, whereas higher numbers are narrower. For instance, f/2.8 is substantially bigger than f/4 and f/11. Since it contradicts our ingrained beliefs, most people find this uncomfortable. Nonetheless, in photography, this is an inevitable reality.

The reason for this is that the term aperture refers to a fractional value.

An f-stop of f/16, for instance, is comparable to the fraction 1/16. Compared to the fraction 1/4, 1/16 is considerably smaller. This is why f/16 is a smaller aperture than f/4. A popular photography-related query is, “What is the best aperture?” Should I set the aperture wide open or somewhat small? There is no one solution; rather, it depends on the photographer and the subject being captured.

Take a look at these sample aperture settings:

  • A 50mm lens with an aperture of f/2 has a 25mm diameter (50mm f/2).
  • When set to f/8, a 50mm lens’s aperture will be 6.25mm wide (50mm/8).

Different lenses have different maximum and minimum aperture numbers or f-stop values; you’ll have to adjust your lens/camera to get the right value.

Most Common f-stops

the scale of the lens aperture
  • f/1.4 — Allows the most light in, but is often only found on high-end consumer cameras
  • f/2.0 – The standard aperture of most consumer cameras
  • f/2.8 — Typically the lowest available f-stop, making it ideal for low-light shooting
  • f/4.0 — Ideal for landscape and wildlife shots
  • f/5.6 — A fantastic all-around aperture for wide-angle shots with subjects that require a shallow depth of field
  • f/8.0 — Background blur becomes more noticeable, altering the depth of field
  • f/11 — If you’re taking macro shots, you’ll want this aperture to noticeably improve the depth of field
  • f/16.0 — The smallest aperture available on most cameras
  • f/22.0 – Only experienced photographers should use this aperture since sharpness begins to degrade at this setting

How Aperture Affects Exposure

portrait of a smiling girl

Changing the aperture can alter several aspects of your photos. Your photos’ exposure is probably the first thing people will notice. By adjusting the size of the aperture, you can control how much light reaches the camera’s sensor and, in turn, how bright the resulting image is.

When the aperture is wide open, more light enters the camera, leading to a brighter final picture. The reverse effect occurs when the aperture is narrowed, darkening the image. It’s common practice to use a wide aperture while shooting in low-light conditions, such as indoors or at night.

To figure out how many f-stops to use, start with the widest setting. Then add or subtract one f-stop for each additional lighting situation you encounter. If you’re shooting in low light, add a couple of f-stops. If you’re shooting outside during daylight hours, take off a few f-stops.

For instance, if you’re shooting a landscape, you should open the aperture wide to capture a lot of the sky. If you’re photographing a person, you’ll need to use a smaller aperture to blur out background distractions.

The result should be a photo that is neither too dim nor too bright; rather, you should aim for a picture that is balanced and contains a lot of details in its composition.

How Aperture Affects Depth of Field

Royal Alcázar of Seville, Patio de Banderas, Seville, Spain

We must now look into the connection between aperture and depth of field. Throughout this article, we’ve discussed depth of field. However, we have not yet defined it or discussed how aperture affects it.

Depth of field refers to how much of your shot is in focus. Simply put, it’s the distance between the nearest and farthest objects in focus. One’s depth of field might be either very shallow or very deep. And the aperture is the setting that controls it all.

To have a shallow depth of field means that only a relatively small section of the image is in focus and this is achieved through wider apertures. This is ideal if you’re taking a portrait or any kind of object photo in which you want to highlight the subject. You can create a more compelling composition by placing blurry foreground objects in front of your subject.

On the other hand, using a small aperture will result in background blur, which is often appropriate for certain types of photography such as landscape and architectural photography. The subject will be sharply focused, but the foreground and backdrop will be blurred. This is called a deep depth of field.

Setting Aperture in Your Camera

camera with  in the hand, focus on display

You can manually set the aperture in two different shooting modes. You can choose between aperture priority and full manual control.

Aperture Priority Mode

Aperture priority mode is a semi-automatic shooting option found in cameras. The user specifies an aperture and/or ISO value, and the camera automatically determines the best exposure. Shutter speed (the only remaining variable) is determined automatically. On the settings wheel, some cameras mark aperture priority as AV (Aperture value) or A (Aperture).

While the camera handles exposure and focusing for you, shooting with only one or two manual settings allows for greater creative freedom than fully automatic shooting. After deciding what will be the focus of the picture, select the appropriate aperture number (f-stop).

When you need to take a lot of shots quickly in a well-lit area but don’t have time to fiddle with the camera’s settings, this can come in handy. In addition to being a useful teaching tool, knowing what shutter speed your camera used under specific lighting situations will help you take better photos in the future.

Manual Mode

When using manual mode, both the aperture and the shutter speed are set by the user. ISO can be set to automatic or manual. Shooting in manual mode is laborious and typically yields no better results than aperture priority. It’s only necessary when the camera’s meter is malfunctioning, or when you need to ensure a consistent exposure in all of your shots.

Mastering aperture settings and their effect on photos will help you take better pictures in a variety of situations, whether you’re using a Nikon, Canon, or another brand of camera. Further post-production tweaks can be made in the editing room.

Maximum and Minimum Aperture

camera lens in the hand

There is a maximum and minimum aperture for every lens. A photographer who understands the relationship between the minimum and maximum aperture will have a much easier time selecting the appropriate lens for any given shooting situation.

Looking at the lens’s specs should reveal its maximum and minimum apertures. The maximum aperture is more relevant to most people since it indicates the maximum amount of light that can be collected by the lens. This determines the environments it will be able to shoot in.

If a camera lens’s aperture can go from f/4 to f/32, then f/32 is the smallest aperture and f/4 is the largest. Because a lower f-number corresponds to a larger aperture (which lets in more light), a larger maximum aperture is both quicker and allows for more light.

In contrast, current lenses often provide a minimum aperture of at least f/16, therefore the minimum aperture is no longer a major concern. Minimum aperture settings are typically used for landscape and architectural photography. The objective is to capture the entire scene, including foreground and backdrop, in sharp focus.

Variable aperture

Variable aperture is commonly found in zoom camera lenses. The aperture of a variable-aperture lens shifts as the lens’s focal length is adjusted. For example, with an 18-55mm lens, the widest aperture is f/3.5 at 18mm. To get the most out of your 55mm focal length, you’ll need to settle for an aperture of no more than f/5.6. Exposure is harder to manage because there is a narrower selection of apertures available. However, lenses with variable apertures are more portable, cheaper, and less of a hassle to use.

Along with exposure and depth of field, how the aperture influences sharpness is an important aspect of photography. Using a very small aperture value or a very large one is not a good idea while taking photos. Since the lens’s diaphragm will be wide open to gather as much light as possible, the lens’s sharpest results will be compromised when using a large aperture.

Similarly, when using a narrow aperture, the effect is the same. If the aperture is too small, an optical phenomenon known as diffraction will cause a drop in image quality across the board.

Since the sharpness of a lens’s aperture varies by model, there is no universal criterion for determining which aperture is best.

However, the aperture that delivers the highest quality in terms of sharpness is always near the lens’s “sweet spot,”: the aperture or f-stop number of a particular camera that produces the sharpest images. You may roughly determine this sweet spot by adjusting your lens’s aperture setting by two or three f-stops from its maximum. If your lens’s maximum aperture is f/4, this range would be between f/8 and f/11.

Put your lens to the test by shooting the same scene with several aperture values and then comparing the results by zooming in on the details to see which aperture produces the sharpest results.

How to Set the Aperture

Here, the procedure will vary based on the lens and camera model you’re using. Nonetheless, you can use these guidelines as a starting point to learn more about aperture adjustment. The following is an illustration for each of the three most prominent camera brands available on the market today:

Canon EOS Rebel T6

Canon EOS Rebel T6
  1. Turn the dial on the top of your camera to manual mode (M).
  2. Hold down the AV +/- button to the right of your camera display.
  3. As you hold down that button, turn the control dial on the top of your camera to the right to get a higher f-stop/smaller hole, and to the left to get a lower f-stop/larger hole.

Nikon D3400

Nikon D3400
  1. Turn the dial on the top of your camera to manual mode (M).
  2. Hold down the +/- button on the top of your camera.
  3. As you hold down that button, turn the command dial to the right to get a higher f-stop/smaller hole, and to the left to get a lower f-stop/larger hole.

Sony a6000

Sony a6000
  1. Turn the dial on the top of your camera to manual mode (M).
  2. Hold down the AEL (Auto-Exposure Lock) button to the right of your camera display.
  3. As you hold down that button, turn the dial to the right to get a lower f-stop/larger hole, and to the left to get a higher f-stop/smaller hole.

Conclusion

Aperture, as one of the three points of the exposure triangle, is an essential concept for any photographer to grasp. Hopefully, you now have a firm grasp on what aperture is and how you may use it to exert more artistic control over your images. The greatest method to learn about aperture in photography, beyond reading the theory and checking the aperture examples, is to get out in the field – get out your camera and start putting your newfound information to use.

Frequently Asked Questions

The aperture of a lens is the size of the opening through which light may enter and reach the camera’s image sensor.

F-stop numbers indicate the degree to which the aperture is open or closed. Normal aperture settings go as follows: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22.

Aperture primarily influences the overall exposure of the image, the depth of field, and the sharpness of the image’s elements.

If the aperture number is larger (f/16, for example), less light is entering the camera. This is the optimal mode for taking photos of groups of people or expansive landscapes, in which you want the subjects to be sharp throughout the frame. Light may enter the camera more easily when the aperture is broadened, making it ideal for low-light shooting.

Aperture is important in photography because it controls how bright an image is, what section of the image is in focus, and how sharp the image appears.

Bret Leon Avatar
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Bret Leon
Bret Leon is a photography enthusiast who indulges in all matters cameras, lenses, gears, themes, editing, trends, and the latest product releases. If he's not trying to freeze time by capturing moments during his grand ventures, you can bet he's looking for the next big content idea.
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