Barrel Distortion

Vincent Bockaert, 123di.com

Barrel distortion is a lens effect which causes images to be spherised or "inflated". Barrel distortion is associated with wide angle lenses and typically occurs at the wide end of a zoom lens. The use of converters often amplifies the effect. It is most visible in images with perfectly straight lines, especially when they are close to the edge of the image frame. See also the opposite effect, pincushion distortion.

Barrel distortion inflates the square Example of Barrel Distortion

Barrel Distortion at dpreview.com

We measure barrel distortion in our reviews as the amount a reference line is bent as a percentage of picture height. For most consumer digital cameras this figure is normally around 1%.

Correcting Barrel Distortion

Barrel distorted images from virtually any digital camera can be corrected easily using software, e.g. Adobe Photoshop CS2.

This article is written by Vincent Bockaert,
author of The 123 of digital imaging Interactive Learning Suite
Click here to visit 123di.com