What is Lens Distortion? Definition, How to Avoid, & Examples

In this guide, we’ll be diving into lens distortion. We will discuss its definition, types, what causes it, how to fix it with Adobe Lightroom, Photoshop, and more.

Let’s dive in.

Intro

You know that feeling when you take a photo with a camera, or a phone and you notice the perspectives are a little… wonky?

Some parts of the picture may seem stretched and may look bigger or smaller than the actual object you are trying to capture.

Well, that feeling is a phenomenon called lens distortion. But what is lens distortion, really? What is the cause of lens distortion?

Is there any way you can avoid it? Well, keep reading and soon enough you will know everything there is to know about lens distortion.

Lens Distortion

What is Lens Distortion?

Lens distortion is an optical phenomenon caused by one of the types of lens failure. Lens distortion happens when the camera fails to be rectilinear.

What is rectilinear? Rectilinear, in photography, is the lens’ ability to “preserve” the straight features in buildings, walls, doors, and other objects, to appear straight in the picture.

Simply put, it keeps straight looking objects straight, not curved.

Some kinds of lenses such as wide-angle lenses are more likely to distort and stretch images for the sake of capturing all angles.

As a result, some straight features that should appear straight in the picture end up appearing distorted and curved.

This is basically what lens distortion is.

Lens Distortion 1

What are The Types of Lens Distortion?

There are several types of lens distortion. Although the appearance of lens distortion can be irregular and with random shapes,

There are at least three kinds of lens distortion that appear most often in photography.

They are barrel distortion, pincushion distortion, and mustache distortion.

Barrel Distortion

Barrel distortion, also known as negative distortion, is a lens distortion where the lines protrude outwards at the center, like a barrel.

Barrel distortion happens when the picture’s center is magnified, and the edges are somewhat shrunken.

The phenomenon creates an effect where the lines are curved around, creating a spherical shape that resembles a barrel.

Barrel distortion happens most frequently in wide-angle lenses, especially fisheye lenses.

Although wide lenses and zoom lenses are not as “dramatic” as fisheye lenses,

They are also prone to creating this barrel-like effect where the middle of the picture is much more magnified than the edges.

Pincushion Distortion

Pincushion distortion, also known as positive distortion, is basically the opposite of barrel distortion.

Instead of getting the image magnified at the center of the focal length, the lines are hunched inwards and appear smaller in the middle, making edges appear bigger.

This distortion elongates the corners of the image, creating a shape that is similar to how a pincushion looks like when you push a pin on it.

This distortion occurs more often in the zoom telephoto lenses.

Mustache Distortion

Mustache Distortion, also known as complex distortion, is a combination of both barrel distortion and pincushion distortion–

creating a wavy image similar to the shape of a mustache.

This type of distortion happens less often than barrel distortion and pincushion distortion. Even it happens less often, it is not a rare phenomenon in the photography world.

In mustache distortion, the barrel distortion magnification appears in the middle of the focal length and the pincushion distortion gradually takes over around the edges.

This can happen the other way around where the pincushion happens in the middle and gradually turns to barrel distortion towards the edges.

This distortion occurs more in older camera lenses.

Barrel Distortion

What Causes Lens Distortion?

Lens distortion is a distortion caused by camera lenses falling short.

Usually, this phenomenon is related to the structure of the lens itself, but the light reaching the camera sensor may also play a role in the occurrence of lens distortion.

Although lens distortion appears more often in certain lenses such as wide-angle lenses and fisheye lenses, lens distortions are actually more common than you would think.

And you should cut yourself some slack because there is no perfect picture, considering that every picture actually has some amount of distortion in it.

Some distortions are visually unnoticeable because they are too subtle to disturb the appearance of the overall image.

This can happen when the various parts of the convex-shaped lens have different focal lengths that causes different magnifications.

These differences make some parts of the image appear misshapen, even though every single one of the objects is focused and sharp.

The causes of lens distortion are different depending on the type of lens distortion.

For example, barrel distortion often occurs in wide-angle lenses, and happens because the view of the lenses is wider than the camera sensor.

This is why the center of the image will appear bigger while the edges will appear smaller.

Pincushion distortion happens when the magnification increases with the distance.

This is why pincushion distortion occurs more often in zoom telephoto lenses because of the further the distance, the bigger the magnification.

Cause of distortion

Why Is It Called Lens Distortion?

It is called lens distortion because even when there are other factors that may contribute to a distortion, the lens is the most probable cause.

Unlike perspective distortion, lens distortion is purely an optical phenomenon that happens due to the shape of the lens itself.

To understand this phenomenon furthermore, we need to also learn the difference between lens distortion and perspective distortion.

Perspective distortion is caused by the position of the camera itself.

For example, if you photograph a building from a lower angle, the shape of the building may look different than when you take the building’s picture from a straight angle.

Perspective distortion can also make more distant objects appear smaller compared to a closer object.

This nature of lens is often used in photography to create some optical illusion such as make some objects appear gigantic, or very small, compared to their actual sizes.

The camera’s position and angle create a certain perspective that makes the object appear differently than its actual shape.

On the other hand, lens distortions happen because of the shape of the lens itself as we have previously discussed.

It can happen no matter how you place your camera.

Of course, the distortion may appear worst at a certain angle, but even when you just take a picture with a straight eye-level angle, the distortion can still be visible.

optical illusion

Can You Fix Lens Distortion?

There are several methods you can use to fix lens distortion.

One of the ways you can do this is by fixing it in the post-production process using photo editing software such as Adobe Lightroom, Photoshop, and Luminar AI.

This popular editing software makes it possible for us to fix lens distortion more simply.

Fixing Lens Distortion in Adobe Lightroom

On Adobe Lightroom, you can choose the Lens Corrections menu. You can use the automatic profile correction to fix your image.

You can click this menu and select the lens you used to take the image.

This feature will automatically correct lens distortion and vignetting at the same time.

The automatic profile correction will help you for the most part and you just have to do some further steps to get the desired result.

But sometimes, the automatic profile correction cannot help especially in severe distortion cases, so you have to fix it manually on the Transform Tab.

The Transform Tab also has an automatic setting. You can try it to see if it helps, but if it does not, you can still use the menus provided below:

  • Vertical

You can use this menu to correct vertical distortion on the image.

  • Level

You can use this menu to level the horizontal features of the image.

  • Auto

The auto menu will balance and correct both vertical and horizontal distortion. It will also help to balance your picture without having to crop some parts of the image.

  • Guided

This menu will help you a lot when you correct the distorted image manually. The guide menu will provide you with lines you can use as a guide.

Following these guidelines, you can easily see the part of the image that is still distorted and needs fixing.

  • Full

The full menu has a similar function as the auto menu. It will balance out the overall image.

The full menu can be used in extreme distortion occurrence but there are some parts of the image that might be cropped.

Most of the menus mentioned will help you get through most distortion cases.

But in very severe cases, you may still need to do extra steps to fix some parts of the image that still appear curved.

You can use the transform slider to manually fix both vertical and horizontal lines.

Fix Lens Distortion

Fixing Lens Distortion in Photoshop

You can fix the lens distortion on the Custom menu. There are some features on Photoshop you can use to fix lens distortion.

  • Grid

This feature will provide you with a grid that you can use as a guide. By turning on the grid, you can easily see the part of the image that is curved and distorted.

  • Straighten Tool

This tool is very helpful in helping you straighten the curved lines. Use the slider in the transform tab to adjust the vertical and horizontal perspective following the grid as a guide.

  • Remove Distortion Slider

This tool will help you correct barrel and pincushion distortion easier in one single step.

Note that the more adjustment you make, the more likely you would need to crop more parts of the image.

Keep this in mind every time you take a picture, so that when you encounter some objects such as buildings.

You know you are going to need to do some lens distortion correction later, you can make sure that you leave enough space for cropping.

Both Lightroom and Photoshop are excellent to use to remove lens distortion. You can use one of them or even combine both of them.

But sometimes, removing some kinds of lens failures in the post-production process does not always give you the best result.

Lens Distortion in Photoshop

One of the things you can do is by preventing lens distortion altogether in the production process. There are some ways you can do to prevent the lens distortion below:

  • Avoid Using Extreme Wide-Angle Lenses

Wide-angle lenses always create distortion. That is what you can expect because the wide-angle lens basically squeezes a wider view into one single frame.

So, lens distortion is normal when you use this kind of lenses especially the ‘extreme’ ones, such as the fisheye lens.

Instead of forcing the camera to fit a wider view into a single frame, maybe you can consider taking some steps back and take the picture from a distance to get a wider view.

  • Keep Some Distance Between You and the Subject

When you take a picture too close to the object, the chance of the lens distortion occurring is even greater.

It may also create a perspective distortion and give you another problem to deal with in post-production.

This is why you need to keep a distance between yourself and the object you want to photograph.

  • Pay Attention to the Composition and Add Some Space

It is particularly important to add some space around the object. This step will help you a lot in post-production.

First of all, by adding some space around your object, the object itself could be safe from the distortion and only the edges, which is the extra space that is being distorted.

The extra space is also extremely useful in post-production work just in case you need to do some cropping.

  • Choose the Lenses with Less Distortion

Most lenses nowadays are already pretty good at avoiding distortion occurrence. Older lenses, however, tend to create more distortion.

So, select your lenses carefully before you go to take some pictures. So many photographers recommend using 50 mm lenses to avoid lens distortion.

This lens is also known for not having optical distortion issues. Lens distortion can be annoying if you do not expect it, but sometimes, it does not have to be bad.

Some photographers use lens distortion on purpose to create a certain perspective or create an optical illusion to their images.

You, too, can use the lens distortion creatively and experiment with different types of photos.

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