Correcting lens distortions
Camera lenses can create distortions in photos. These distortions appear most often in wide-angle photos, in close-up photos taken with cameras with fixed focal ranges, and in photos taken with cameras that have low-quality lenses (such as disposable cameras).
Important! It is strongly recommended that you correct the lens distortion in a photo before cropping it.
Types of lens distortion
Corel PaintShop Pro can correct three common types of lens distortion, all of which make straight lines appear curved:
• Barrel distortion — Photo looks pushed out at the centre. For distortion corrections to work properly, the axis of the camera lens must coincide with the centre of the image.
• Fisheye distortion — Photo looks as though it has been pasted onto a sphere or blown up like a balloon. The edges of the photo look compressed.
• Pincushion distortion — Photo looks pushed in at the center
To correct barrel distortion
Edit workspace
1 Choose Adjust Barrel Distortion Correction.
The Barrel Distortion Correction dialog box appears.
2 Look for curved lines in the image, and straighten them by typing or setting an appropriate value in the Strength control.
3 Click OK.
By marking the Preserve central scale check box, you can add or remove pixels from the image, which changes the scale at the center of the picture. Changes to the width and height of the original image are displayed in the Result Size group box.
To correct fisheye distortion
Edit workspace
1 Choose Adjust Fisheye Distortion Correction.
The Fisheye Distortion Correction dialog box appears.
2 Remove the distortion by typing or setting an appropriate value in the Field of View control.
3 Click OK.
By marking the Preserve central scale check box, you can add or remove pixels from the image, which changes the scale at the center of the picture. Changes to the width and height of the original image are displayed in the Result Size group box.
To correct pincushion distortion
Edit workspace
1 Choose Adjust Pincushion Distortion Correction.
The Pincushion Distortion Correction dialog box appears.
2 Look for lines in the image that are curved, and type or set a value in the Strength control until they become straight.
3 Click OK.
By marking the Preserve central scale check box, you can add or remove pixels from the image, which changes the scale at the center of the picture. Changes to the width and height of the original image are displayed in the Result Size group box.