Advanced Editing

Correcting barrel distortion

Written by Gail Bjork

A step-by-step guide to correct lens barrel distortion when editing a digital image.

Barrel distortion is a curving distortion that happens to vertical lines when using a wide angle lens.

Barrel distortion can be improved by using any photo editing program that has tools to correct camera lens distortions. Adobe Photoshop 7 was used to illustrate this tutorial, but other photo editing programs have similar tools. Check your software’s HELP menu as the tool may be located under a different menu, or called by another name.

Original with barrel distortion

Original with barrel distortion

Barrel distortion corrected

Barrel distortion after adjustments

How to improve barrel distortion

This tutorial illustrates the technique using the Perspective and Free Transform tools in Photoshop 7:

Perspective Tool

perspective

1. Select the Perspective Tool (Edit menu > Transform > Perspective). Once the Perspective Tool is selected, pull one of the upper handles to the right (or left).

Free Transform Tool

free transform

2. A subject tends to shorten when using the Perspective Tool so, next, use the Free Transform tool (Edit menu > Free Transform) to drag the middle of the photo upward. Some cropping of the image will occur.

It is important to make adjustments to barrel distortion on a full sized image since the image will have to be cropped. Only after the distortion is tweaked should an image be further edited such as adjusting brightness and contrast or sharpened.

Other programs that correct barrel distortions

Other photo editing programs include more sophisticated tools to correct barrel and other lens distortions such as  PTLens. Photoshop CS and above have a Lens Correction filter.

About the author

Gail Bjork

Gail Bjork, who is passionate about digital photography, is the owner and editor of Digicamhelp.Gail is the author of three illustrated ebooks about digital photography. A number of her photos and digital photography related articles appear at other websites.In 2006, a series of her photos, People in the Louvre, were exhibited at the Underground Photo Gallery
in Iisalmi Finland. Eight of her photos taken in the Florida scrub are on permanent exhibition at Parrish Medical Center in Titusville, Florida.Gail served twelve years as an elected member of The School Board of Palm Beach County, Florida, one of the largest school districts in the U.S. She has also been the editor of a small town newspaper and a free-lance writer. Gail and her husband owned and ran several small businesses.

3 Comments

  • Thanks for the response. I have found some success using the “pinch” and “spherize” in Photoshop versions before CS3. Pinching works if you only need a little bit of correction and you need to keep the whole photo. Spherizing works better, but you’ll need to about double the canvas size to get it to work before you do it, and you’ll still need to crop it down when you finish.

  • Stephen, you are correct with everything you point out. But, for some, the compromises faced when editing for barrel distortion are preferable to the original distortion. A program such as Photoshop CS 3 offers a feature that can extend the edge pixels of the image. But even this may cause some distortion at the edges so an image may still benefit from cropping.

  • Yeah hey that’s great, but just tweaking the perspective doesn’t fix the curved lines on the photo. They’re still curved, just at a different angle. Even on the sample, the buildings and lamp post are still bendy, even though theyre still more-or-less vertical.
    Also, the sample photo had been cropped, because barrel distortion wraps around the center of the camera’s lens, not the bottom.
    And what about the fact that the distortion increases closer to the edge of the photos?