Correcting Lens Distortion in Adobe Photshop CS5
Note: This excerpt does not include the lesson files. The lesson files are available with purchase of the book.
The Lens Correction filter fixes common camera lens flaws, such as barrel and pincushion distortion, chromatic aberration, and vignetting. Barrel distortion is a lens defect that causes straight lines to bow out toward the edges of the image. Pincushion distortion is the opposite effect, causing straight lines to bend inward. Chromatic aberration appears as a color fringe along the edges of image objects. Vignetting occurs when the edges of an image, especially the corners, are darker than the center.
Some lenses exhibit these defects depending on the focal length or the f-stop used. The Lens Correction filter can apply settings based on the camera, lens, and focal length that were used to make the image. The filter can also rotate an image or fix image perspective caused by tilting a camera vertically or horizontally. The filter’s image grid makes it easier and more accurate to make these adjustments than using the Transform command.
In this exercise, you will adjust the lens distortion in an image of a Greek temple.
- Click the Launch Bridge button (). In Bridge, navigate to the Lesson05 folder. Double-click the 05D_Start.psd image to open it in Photoshop.
The columns in this image bend toward the camera and appear to be warped. This photo was shot at a range that was too close with a wide-angle lens.
- Choose Filter > Lens Correction. The Lens Correction dialog box opens.
- Select Show Grid at the bottom of the dialog box, if it’s not already selected. An alignment grid overlays the image, next
to options for removing distortion, correcting chromatic aberration, removing vignettes, and transforming perspective.
The Lens Correction dialog box includes auto-correction options. You’ll adjust one setting in the Auto Corrections pane and then customize the settings.
- In the Correction area of the Auto Corrections pane, make sure Auto Scale Image is selected, and that Transparency is selected from the Edge menu.
- Select the Custom tab.
- In the Custom pane, drag the Remove Distortion slider to about +52.00 to remove the barrel distortion in the image. Alternatively, you could select the Remove Distortion tool () and drag in the image preview area until the columns are straight.
The adjustment causes the image borders to bow inward. However, because you selected Auto Scale Image, the Lens Correction filter automatically scales the image to adjust the borders.
- Click OK to apply your changes and close the Lens Correction dialog box.
The curving distortion caused by the wide-angle lens and low shooting angle are eliminated.
- (Optional) To see the effect of your change in the main image window, press Ctrl+Z (Windows) or Command+Z (Mac OS) twice to undo and redo the filter.
- Choose File > Save As. In the Save As dialog box, name the file Columns_Final.psd, and save it in the Lesson05 folder. Click OK if a compatibility warning appears. Then, close the image.