Aperture is one of three fundamental camera settings you need to understand to become a better photographer. 

I know that most beginning or hobby photographers are happy to point their camera towards something beautiful and fire away while letting the camera decide the best settings. This is fine if you’re just out there collecting memories, but it won’t work if you want to become a better photographer.

You see, you need to understand the three components of the Exposure Triangle; shutter speed, aperture, and ISO. Taking control of these will let you deliberately and consistently create beautiful images. Fail to do so, and you are gambling with your pictures.

Aperture is a fundamental camera setting that plays a vital role in exposure, sharpness, and depth of field.

In other words, understanding what aperture is and how to use it will give you a lot of advantages.

Keep reading, and you’ll learn everything you need to know about aperture in photography.

Introduction to aperture in photography

What is Aperture in Photography?

Aperture, as well as the other fundamentals of photography, can get confusing. Despite getting a bit technical at times, I’ll do my best to keep the explanations throughout this article as simple as possible.

So, what is aperture?

Simply put, aperture refers to the opening within the lens where lights pass through to the camera’s sensor. This hole’s size is adjustable and known as a f-stop.

A large hole allows more light to reach the sensor than a small one. This means we need more time for enough light to reach the sensor and give a well-exposed image.

I strongly recommend reading about the Exposure Triangle to understand the sentence above fully. That will explain to you the relationship between the three fundamental camera settings.

Aperture in the Exposure Triangle

Now, understanding aperture in photography is more advanced than this. You see, the aperture doesn’t only affect the amount of light that reaches the camera sensor. There are two more things it impacts: depth of field and sharpness.

But before we get to that, let’s take a step back and look at what an f-Stop is and how to understand the aperture values:

What is F-Stop?

Quite likely, you’ve noticed some strange numbers on your lens. No, I’m not talking about the focal length but something that looks like this: f/2.8 or f/4.5-5.6.

That number refers to the widest aperture for your lens.

An f-Stop is the aperture’s numerical value and specifies the hole’s size. A low number means a big opening, while a higher number means a small opening. One stop represents the doubling or halving of light that reaches the sensor. Again, it is more complex than I explained above, but that’s all we need to know.

Aperture and the Exposure

Exposure (image brightness) is the primary topic the aperture affects. I’ll repeat once more; an open aperture allows more light to pass through than a narrow aperture.

But what exactly does this mean?

Let’s do an experiment:

Set your camera to Manual Mode with an aperture of f/10, ISO of 400, and shutter speed to a value that gives a well-exposed image.

Need help determining what shutter speed to use? Set the camera to Aperture Priority Mode, apply the same settings, and see what shutter speed this gives. Write it down and apply it in Manual Mode.

Take an image and then, without moving the camera, change only the aperture to f/4 and take a new photo. Do you see a difference between the two images? The second is a lot brighter.

Now, change the aperture to f/22 and take another shot. What happened this time? The image is considerably darker.

So, what did we learn? A narrow aperture (f/22) allows less light to reach the sensor.

If you keep the same f-stop and slow down the shutter speed, you’ll see that you can balance the exposure and get the correct amount of light.

Why? Because leaving the shutter open for a longer time will allow more light to make its way through the tiny opening.

So, wouldn’t it be best to always use an open aperture? Not quite. That brings us to the next topic:

Aperture and Depth of Field

Depth of field is the second aspect within a photo that the aperture affects, and it refers to how much of the image is in focus. 

This is arguably the most important part of aperture. Even more important than exposure (this is because shutter speed is often the go-to setting for exposure)

You see, changing the aperture changes how much of your photo is in focus. 

Shallow Depth of Field

An open aperture such as f/2.8 leads to a shallow depth of field. This means that less of the image is sharp and in focus. The image below is a typical example; the flowers are in focus while the background elements are blurry.

Shallow Depth of Field in Photography

This type of aperture is most commonly used when wanting to blur the background. However, it’s also a vital ingredient for night photography.

Recommended Reading: When to Use an Open Aperture in Landscape Photography

Large Depth of Field

A narrow aperture such as f/22 has the opposite effect and gives us a large depth of field. That means more of the image is in focus, such as the image below, where both the foreground and background are sharp.

Large Depth of Field in Photography

These apertures are most commonly used when photographing grand landscapes or scenes where you need front-to-back sharpness. 

Now, this is where it gets trickier. While a narrow aperture means more of the photo is in focus, it’s not the sharpest.

Let me explain: 

Aperture and Sharpness

Sharpness is the third aspect of photography that aperture impact.

A general rule of thumb is that you find the sharpest aperture to be 2 or 3 stops from the widest value of the lens. This means the sharpest aperture for an f/2.8 lens is f/5.6, while it’s f/7 for a lens with f/4 as the widest aperture.

Take a look at this table to see what the sharpest aperture is for your lens (note: slight changes may occur between different manufacturers):

 Widest Aperture of the LensSharpest Aperture
 f/2.8f/5.6 to f/8
 f/4f/8 to f/11

This means that an aperture two to three stops away from the widest is where you’ll get the sharpest result. Going beyond this value may lead to a loss of sharpness where, ultimately, the image appears soft.

What is the Best Aperture for Photography?

I wish it were as simple as saying that you should always use a specific aperture, but that’s not quite the case. However, there are a couple of guidelines that you should follow and keep in mind:

  • An open aperture results in less of the image being in focus
  • A narrow aperture results in more of the image being in focus
  • The sharpest aperture is found two to three stops away from the widest aperture of the lens
  • Your choice of aperture depends on several factors, such as what you’re photographing, the outside exposure, and your creative vision.

That being said, here are a couple of general pieces of advice on what aperture to choose:

  • f/7 to f/11 is the go-to for most wide-angle landscape photography where you want optimal sharpness from front to back (focus stacking might be necessary when using compositions that involve elements both near and far from the lens)
  • f/2.8 or wider is ideal for macro photography or other images where you want to blur the background
  • f/4 or wider is perfect for night photography or other low-light situations
  • f/16 and higher should generally be avoided due to diffraction and lack of sharpness

Keep in mind that these are just guidelines and that every case is different. Sometimes you have to make some hard choices, which can lead to using apertures you generally would avoid.


The aperture is the most difficult of the three fundamental camera settings, as it affects multiple things at once. What seems like the best option for one aspect is the worst for another.

That being said, it comes across as more complicated than it is. It takes a little trial and error, but you quickly understand that there are just a few f-stop values that you stick with for most situations:

  • An aperture of f/5.6 to f/11 for general photography (exact value depends on your lens and composition)
  • An aperture of f/2.8 or lower for images where you want to blur the background

I hope this helped you gain a better understanding of aperture in photography. Please don’t hesitate to leave any questions or comments below.


This was the third part of our fundamental camera settings series. You can find the other parts here:
Part 1: Understanding The Exposure Triangle
Part 2: Introduction to Shutter Speed in Landscape Photography
Part 3: Introduction to Aperture in Landscape Photography
Part 4: Introduction to ISO in Landscape Photography