What is Aperture? Photography Definition, Tips, and Examples

This is a guide covering aperture.

In this glossary definition you’ll learn about:

Aperture is the single most important factor in photography. No matter how good your photography skills are, a bad aperture will mess everything up.

Now, let’s just start from the basics and climb from there.


What is Aperture?

Aperture is an opening in a lens through which light travels. Larger apertures will make your image brighter. Smaller apertures will cause your image to appear darker. While medium apertures display “enough” amount of light.

So, all light that passes into the camera is controlled by the aperture. It’s easier when you compare it with real-life situations.

Have you seen how big a cat’s pupil becomes when in the dark? They become massive compared to the daytime.

In dark environments the iris expands, making pupils appear bigger. In contrast, your pupils will become smaller in areas with bright lights.

The same thing applies to the aperture. You can either make it bigger or smaller depending on your goal and environment.

Aperture can also add depth to your image. Depth of field controls your camera focus.

Correct choice of depth of field will make your image appear exquisite. A beautifully blurred background that perfectly emphasizes the importance of your subject.

That should pretty much define an aperture for you. But do you know the optimal amount of aperture?

aperture image
Photo by Pixabay

Is It Better to Have Higher or Lower Aperture?

I’ll just say that medium is premium. You get the best of both worlds without sacrificing the photo quality.

Being stuck at a higher aperture of lens will just make everything bright. Which is good for low-light conditions, but it limits your depth of field.

Exclusively using the lower aperture will force you to only shoot at bright conditions. It does give you a deeper depth of field, which is often a good thing.

It really depends on how you want the finished product to look like. While aperture affects the depth of field and exposure, you can still do something about it later.

Every option has its own special place for every photographer.

The better option is to always adjust your aperture. So, let’s talk about a good aperture, shall we?

What’s Considered A Good Aperture?

Well, it depends.

Look at the brightness of your environment. Is it too dark that your subject is shrouded in darkness? Or is it just obnoxiously bright?

Naturally, you would want a higher aperture for darker environments. Using large apertures such as f/2.8, f/4, f/5.6 should be enough.

On the other hand, you should opt for a lower aperture if you’re in a bright environment. Maybe use f/5.6 or f/8 to make it appear natural.

BUT, your aperture will affect the depth of field.

Choosing f/16 as your aperture will allow you to catch the details in the background. Contrary to that, an f/2.8 aperture will just blur your background.

Aperture does affect the incoming light, which may worry you. Don’t panic my friend, you can still adjust the brightness by changing the shutter speed.

You could also change your ISO to adjust the exposure if needed.

It’s always better to change your aperture based on your needs. I’d say using a medium aperture of lens will do just fine.

Your background and foreground will appear slightly sharp. Not the best, but comfortable enough.

Photo by McKayla Crump

What Is F-Stop?

You should have noticed an “F/8” on your camera. Let’s call it an aperture f-stop.

You can commonly locate it at the LCD screen and accompanied by a certain number. Some cameras don’t use the slash (“/”) but it doesn’t really matter.

F-stops will tell you the aperture size. Large apertures use smaller numbers, while smaller apertures use the bigger ones.

Apertures are basically fractions. An f/4 is larger than f/16 because of fractions.

Larger apertures are closer to 1 (or 0,95 to be precise). Continue counting and the aperture will become smaller.

It confuses many people at the start, but I’m sure that you’ll get used to it.

How Aperture Affects Exposure?

Remember about the eye thing that was mentioned before? Well, it answers this question too.

Pupils become bigger to allow more light to be absorbed. Giving us (and also animals) an ability to some degree, see in the dark.

Larger apertures allow more light to enter the sensor. This results in photos ending up with more exposure. It also conveniently reveals the small details of your subject.

Smaller apertures will stop light from entering the sensor.

Full stops will double or half the amount of light retrieved. An aperture f-stop of 1.4 will allow twice the amount of light compared to an f/2.

pupil exposure
Photo by Michael Morse

How Aperture Affects Depth Of Field?

Depth of field is the sharpness of your photos. A “shallow” depth of field blurs the background and focuses on the foreground.

Larger apertures allow you to direct the viewers to focus on the subject. It’s as if you’re placing them on a pedestal and making those subjects as the highlight.

It “separates” the subject from the busy background that would otherwise add no value.

Being the complete opposite, a “deep” depth of field focuses on both foreground and background. Giving both an optimal amount of sharpness.

Smaller apertures are common for landscape and architectural photography. It gives a complete sharpness from front to back.

You will run into some minor issues if you stray beyond f/22. Feel free to explore the usage of every aperture, big or small.

depth of field
Photo by Doug Robichaud

How to Pick the Right Aperture?

Resuming the topic about good aperture, this section will be more detailed.

I’m going to assuming that you can also adjust shutter speed and ISO to adjust both sharpness and exposure. Selecting the right aperture begs you to decide on the purpose of the shot.

This leads to our first question, are you focusing on something in the foreground, background, or both?

The result of your decision will decide whether you need large or small apertures. Giving you a rough estimation to start before adjusting.

After finding the perfect aperture, you may need to adjust the exposure. Change your shutter speed and ISO to properly adjust the exposure.

Voila, it’s all done! Well, you may need to practice and read a couple more articles to master it.

But hey, progress is still progress, right?

How to Set Aperture in Your Camera?

This is assuming that you’re going hard-core and want to change aperture in manual mode.

A little disclosure that I’m using a Nikon D5000 as a reference. Methods differ between various and older cameras.

  • First of all, move the dial on the top the camera to “M.” Proceed to press and hold the +/- button below the shutter.
  • Rotating the rear command dial to the left will decrease the aperture and vice versa. Left for small aperture, right for a bigger aperture.

While on a Nikon 5200, 3200, and most canon rebels the methods are similar:

  • For Canon users, you will need to hold the AV button. Hold it and spin the dial to adjust the aperture.
  • On Nikons, there’ll be a +/- button on top. Hold it down and spin your thumb dial to set the aperture.

Other camera models use a dial to change apertures. Usually, the higher end camera (D7000, Canon 7D, etc.) has its own dial to change the aperture.

set aperture in camera
Photo by Federico Bottos

What Does Aperture Do To Photos?

Aperture brings various effects to your photo, starting with exposure, depth of field, and many others. We’ll explain a couple of effects that often correlate with aperture, such as;

  • sharpness
  • diffraction
  • small apertures capturing noisy specks
  • the starburst effect.

Let’s go!

Various Depth of Field

Every area of photography uses the aperture a bit differently. Portrait photographers typically use wide/large apertures around f/1.4 to f/2.8.

This effectively guides the viewer’s attention to the centre of the photo. The so-called “creamy” and “dreamy” will always appear in a portrait photographers portfolio.

While landscape photographers take advantage of the smaller aperture to capture… landscapes. It allows them to capture everything with enough sharpness.

Photo by JJ Ying


Aperture can also negatively affect your photos. Bringing hazards to your sharpness through diffraction and aberration.

Putting it simply, diffraction is the loss of sharpness because of tiny apertures. Light interferes with itself and becomes blurry.

You won’t really notice it while using apertures between f/8 to f/16. Apertures smaller than f/22 will usually mess things up, avoid it.


A larger aperture will give you a very shallow depth of field. Effectively blurring everything behind and subjects far from you.

Smaller apertures provide greater depth, giving a better overall sharpness. Yet, the “best” sharpness lies around f/5.6.

A different lens with varying quality will change this approximate number. Take it for a test drive to find the perfect medium aperture.

Small Apertures Doing Their Job Excessively

Photography using small apertures around f/16 will give you a large depth of field. But, you may also capture some unwanted detail.

Small details that would just add useless noise like a water droplet, a speck of dirt, the list goes on.

You can prevent this by using a medium aperture around f/5.6. Constantly cleaning the lens when dirty should also do the trick.

But in other cases, it won’t always be that easy.

Small specks of dust are clear as day when using tiny apertures. Usually, they’re just invisible when using large apertures.

This problem highlights the importance of clean camera sensors.

Fortunately, a quick edit using Photoshop or even Lightroom will help. The process may not be hasty and elegant, but it’s then just leaving it there.

Next time if you’re planning to take a picture through a jar, use a medium aperture. It just makes everything look cleaner.

small aperture
Photo by PhotoMIX Company

Starburst or Sunstar Effect

This “starburst” effect is commonly found in portrait photographs.

This effect is mostly underappreciated, but it’s just beautiful. It’s the sunbeams that omit when you shoot a partly blocked source of light.

In most cases, that bright source of light would be the glorious sun.

Smaller apertures will result in a stronger effect. Photographers commonly use a smaller aperture around f/11 to capture this effect.

An odd number of aperture blades will often hold twice the amount of sunbeams. While cameras with an even amount of aperture will omit the same amount of beams based on its blades.

Using a camera with 9 aperture blades will give you 18 sunbeams. While the 8 amount of blades will only have 8 beams.

The even amount of blades will make the sunbeams overlap, making it only showing a minimal amount of beams.

Some lenses capture the effect better than others. Some popular lenses used for “starburst” catching are the EF16-35mm f/2.8L II USM and the more common Canon 16-35mm.

Use what you have first and try using a smaller aperture. See how defined and clear the effects are, then decide to buy a new one or not.

sunbeam aperture
Photo by Pixabay

Final Remarks

Aperture definitely plays a big role when shooting your photos. Each aperture has its own use for every photography niche.

You learnt the ways to find the optimal aperture, the effects that show up with it, and the ways to set it up in manual mode.

Learning and getting used to the aperture will speed up your photography journey. Mastering it will bring you a step closer to glory.

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