Photo Tip of the Week: How to Fix Lens Distortions
In this step-by-step image-editing project Managing Editor James Ostinga explains how to reduce lens distortions and boost the visual impact of your compositions.
Software: Adobe Lightroom 4
01 DOWNLOAD START IMAGE
Click here to download the free start image. This image was photographed with a wide-angle lens at ground level, which has has introduced a fair amount of distortion and strong converging verticals. We can minimise that using Adobe Lightroom’s Lens Correction controls. (Note: If you prefer, there are similar controls in recent versions of Photoshop CS – go to Filter > Lens Correction.)
The starting image. Note the convergence of vertical lines at the top of the image.
02 IMPORT TO LIGHTROOM
Open Lightroom and in the main menu choose File > Import Photos and Video. In the import workspace locate the image you downloaded in the previous step and click the Import button.
Importing a photo to Lightroom 4.
03 DEVELOP MODULE
The image now appears in Lightroom’s image library. Press the D key on your keyboard (or click Develop at the top of the screen) to open the image in the Develop module. Before you make any changes click the arrow on the left of the screen to hide the panel on the left. This frees up some screen real estate and makes it easier to see what you’re doing.
Lightroom 4's 'Develop' module.
04 LENS DISTORTION
Scroll down the panel on the right until you find the Lens Correction controls. Click Profile and make sure the checkboxes Enable Profile Corrections and Remove Chromatic Aberration are ticked. This simple step removes the characteristic lens distortions for this particular camera-lens combination, though we still need to manually remove the perspective distortion.
Lightroom's Lens Correction panel.
05 SCALE SLIDER
Still in the Lens Corrections panel, click the Manual tab to bring up the Transform sliders. To make it easier to see what’s going on, move the Scale slider left to a setting of 87. This will make it easier to see what’s happening when we start manipulating the shape of the image. Be aware though that the Scale setting does actually resize the image, so be careful not to reduce it any more than you need – in some cases you may find it best to reset it to 100 once you have finished with the Transform sliders.
06 ROTATE SLIDER
Go to the Rotate slider. Note that a grid appears over the image as soon as your cursor moves over any of the Transform sliders, making it easy to see how much correction is required. Drag the Rotate slider right to turn the image right and level the horizontal lines in the image. You don’t have to be too precise here – close enough is good enough for now. We used a setting of 3.1. Note: If you need to zoom, simply click on the image. To zoom out click on the image again.
07 VERTICAL SLIDER
We can use the Vertical slider to help reverse the convergence of the vertical lines in the image. Drag the Vertical slider left to a point where the towers on the left of the image and the windows on the right of the image begin to look more upright. At this point, you’ll find that it’s not possible to get everything right. The setting that works best for the right side of the image is about -31, while -51 seems to be best for the left. For the time being, just pick a number in the middle, say -40.
08 HORIZONTAL SLIDER
Move the Horizontal slider left and right to see what effect it has on the image. The plane of the building starts to look squarer as you move the slider left of centre. Try a setting of -14. That’s looking pretty good, though the change to the Horizontal slider has very slightly moved the angle of the horizontal lines in the image. To compensate, move the Rotate slider back to +2.9.
09 BEFORE AND AFTER
To see a “before and after” of the image press the Y key on your keyboard. Press Y again to return to the normal view. (Note that all changes in Lightroom are non-destructive, so you can return to the original 'unedited' image any time you like.)
Press 'Y' on your keyboard to bring up a 'before and after' view.
10 CROP AND RETOUCH
The final step is to crop the image. Choose the Crop Tool at the top of the panel and click and drag over the image. Press Enter on your keyboard to apply the crop. You have a couple of options at this stage. You can crop the image tightly to get rid of the grey corners, or crop it more loosely and use Photoshop’s Clone Stamp or Patch Tool to add extra sky to fill the space.
To export an image to Photoshop go back to the Library module and right-click the image. Choose Edit In > Adobe Photoshop CSX. If you don’t use Photoshop, but do have another software package that allows cloning, choose Export > Export… to save a version of the image for later retouching.
In this example we’ve also made some small tonal edits, and added some noise for a more filmic look, but we’ll save those changes for another day. For now, have a go at correcting the perspective of one of your own images. Good luck!
Exporting an image from Lightroom for further editing in Photoshop 6.
Adding sky with the Content Aware Patch Tool.
The final corrected image.
Article first published in Australian Photography + digital (August 2012).