Distortion happens with both telephoto and wide angle lenses, though the actual type of distortion is different for different focal lengths. You know when an image is distorted, because it’s either skewed out of shape or gives an unreal perspective. In this video John Greengo demonstrates how distortion affects photos shot with wide angle lenses:
Barrel Distortion
There are two different types of distortion that plague wide angle lenses. In the image below, you see a classic example of barrel distortion compared with the same image corrected in post-processing.
Barrel Distortion: Original vs. Corrected Image
Barrel distortion is when the image is twisted like a barrel. The curved horizon line is a giveaway. Most wide angle lenses suffer from this distortion. Barrel distortion can be easily corrected in post-processing with a single-click.
Foreshortening
Foreshortening is the other type of distortion common with wide angle lenses. Take a look at the series of images below:
Foreshortening at 35mm
Foreshortening at 28mm
Foreshortening at 24mm
Foreshortening at 20mm
Foreshortening at 17mm
As the lens is zoomed out from 35mm all the way to 17mm, the foreground assumes a larger a proportion compared to the background. Notice how the chair appears larger at 28mm than at 35mm when compared to the beds in the foreground.
A similar effect can be noticed in the height of the walls. At 17mm the height of the walls closer to the camera appears larger than the height of the walls at the back of the room.
To really drive home the point, Greengo demonstrates how distortion affects a perfectly round object like a soccer ball. When the ball is placed at the corner of the frame at a focal length of 35mm or shorter, distortion is prominent. At 50mm or longer there is no distortion at all.
The knowledge of how and at what focal lengths distortion can impact your images can be a useful piece of information. For example, most photographers don’t quite like photographing people with a wide angle lens, citing distortion. However, as demonstrated with a soccer ball in the example above, even with wide angle lenses, distortion is only seen toward the corner of the frames and not so much at the center. You can safely photograph people with a wide angle lens so long as you keep them at the center of the frame.
Photographers often suggest that an 85mm lens (or slightly longer) is the ideal focal length for photographing people, because such lenses suffer from little to no distortion at all. The lack of distortion noted with a 100mm lens in the above example with the soccer ball simply confirms this believe.
Advantages of Distortion
Then again, distortion has its own advantages. Landscape photographers routinely use this effect of wide angle lenses to exaggerate and thereby place something prominently in the shot.
Distortion is not always a bad thing.
In the example above, the railroad tracks in the foreground appear much larger than the actual railroad car in the background.
Distortion isn’t always a bad thing. If you know why and when it happens, you can put it to creative use in your photography.
Go to full article: How to Work With Wide Angle Lens Distortion
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Article from: PictureCorrect
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