Have you noticed a straight horizon bending into a curve near the edge of a photo, or a door frame bowing slightly? That is lens distortion. It is one of two very different things photographers call "distortion". The other, perspective distortion, comes from where you stand, not from the lens. Mixing them up leads to the wrong fixes. This lesson explains both clearly and shows you how to avoid or correct each one.
Two kinds of distortion
| Lens (optical) distortion | Perspective distortion | |
|---|---|---|
| Cause | The lens design bends straight lines | The camera's position: distance and angle |
| What you see | Straight lines curve, especially near edges | Near things look too big or far things too small; vertical lines lean |
| Changes with | The lens and the focal length you use | Where you stand and how you point the camera |
| Main fix | Lens correction in camera or editing software | Change your position, or use perspective tools |
Perspective distortion was explained in perspective, camera position and subject distance and compression. This lesson focuses mainly on lens distortion, then shows how to tell the two apart.
The three types of lens distortion
Lens distortion means straight lines in the scene record as curved lines in the photo. It happens because the lens magnifies the edges of the image slightly more or less than the centre.
| Type | What it looks like | Where it is common |
|---|---|---|
| Barrel | Straight lines bow outward, as if wrapped around a barrel | Wide-angle lenses and the wide end of zoom lenses |
| Pincushion | Straight lines bend inward toward the centre | Telephoto lenses and the long end of zooms |
| Mustache (complex) | Lines bow outward near the centre and inward near the edges, like a curly mustache | Some wide-angle designs and large-range zooms |
Remember:Many general zooms show barrel distortion at the wide end that gradually changes toward pincushion at the long end. Lenses designed for straight lines, such as many primes for architecture, show very little.
Fisheye lenses bend lines on purpose, as you saw in specialty lenses. That is a design choice, not a fault.
When lens distortion matters
Lens distortion is most visible with straight lines near the edges of the frame: horizons, buildings, door frames, shelves, the edges of a product. In portraits of people, landscapes without straight lines, or nature scenes, a little distortion is usually invisible.
Mild barrel distortion can even be slightly flattering for some subjects, but for architecture, interiors and product photos, clients expect straight lines to look straight.
How to correct lens distortion
- In the camera: most modern cameras have a lens correction setting that fixes distortion in JPEGs automatically; some mirrorless lenses are designed to rely on this correction.
- In editing software: programs such as Lightroom and Camera Raw contain lens profiles. Turning on profile correction straightens lines with one click for supported lenses.
- Manually: a distortion slider can fix simple barrel or pincushion; mustache distortion is harder and usually needs a proper profile.
Tip:Correction slightly stretches parts of the image and crops the edges, so leave a little extra space around important subjects if you know you will correct heavily.
You will learn the editing side fully in perspective and geometry correction.
How to tell which distortion you have
| What you see | Likely type | Fix |
|---|---|---|
| The horizon curves when placed near the top or bottom edge | Lens distortion (barrel) | Lens profile correction |
| Shelves bend inward at the edges at a long focal length | Lens distortion (pincushion) | Lens profile correction |
| Building walls lean inward toward the top | Perspective (camera tilted up) | Keep the camera level, or perspective correction |
| A close-up face has a big nose | Perspective (too close) | Step back and use a longer focal length |
| People near the corners of a wide photo look stretched | Mostly a wide-angle projection effect at the edges | Keep people away from the corners |
The last row is a special case: rectilinear wide-angle lenses keep lines straight by stretching shapes near the corners. Round objects and faces there can look oval and wide. Correcting barrel distortion does not remove this, so the best solution is composition: keep people and round objects nearer the centre.
Common mistakes
- Blaming the lens for leaning buildings: that is perspective from tilting the camera.
- Blaming perspective for a curved horizon: that is barrel distortion; turn on lens correction.
- Placing the horizon near the edge with a wide zoom: barrel distortion shows most there.
- Using a slider on mustache distortion: it often makes the corners worse; use a lens profile.
How professionals handle distortion
Professionals in architecture, interiors and product work keep the camera level, choose lenses with low distortion, and apply lens profile corrections as a standard step. They also know which distortions to leave alone: in a candid portrait or a natural landscape, a little curve rarely matters. They fix perspective problems with position first and software second, because moving the camera gives the most natural result.
Practical examples
A beach horizon
- Situation
- With a wide zoom at 18mm, the sea horizon near the bottom of your photo bends into a smile shape.
- What to do
- You turn on lens profile correction in your editing software.
- Why it works
- This is barrel distortion from the lens, strongest near the edges.
- Result
- The horizon becomes perfectly straight.
A tall office building
- Situation
- The building appears to lean backward even after lens correction.
- What to do
- You reshoot with the camera level and step further back, then crop the empty foreground.
- Why it works
- The lean came from tilting the camera up, a perspective effect that lens correction does not fix.
- Result
- The building's walls stand straight and vertical.
Key points
- Lens distortion comes from the lens; perspective distortion comes from camera position.
- Barrel distortion bows lines outward (wide); pincushion bends them inward (telephoto); mustache mixes both.
- Lens distortion shows most on straight lines near the frame edges.
- Correct lens distortion with in-camera correction or lens profiles in editing.
- Fix leaning buildings and big noses by changing position, not with lens correction.
Frequently asked questions
What is barrel distortion?
What is pincushion distortion?
What is the difference between lens and perspective distortion?
How do I fix lens distortion?
Conclusion
Lens distortion curves straight lines because of the lens design, while perspective distortion comes from where you stand and how you point the camera. Correct lens distortion with profiles, and correct perspective by moving. Next, you will look at other optical limitations of lenses: vignetting, color fringing and diffraction.
Finished reading? Track your progress through Lenses and filters.