Pincushion Distortion

Vincent Bockaert, 123di.com

Pincushion distortion is a lens effect which causes images to be pinched at their center. Pincushion distortion is associated with tele lenses and typically occurs at the tele 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, barrel distortion.

Pincushion distortion deflates the square
Example of
Pincushion Distortion

Pincushion Distortion at dpreview.com

We measure pincushion distortion in our reviews as the amount a reference line is bent as a percentage of picture height. For most consumer digital cameras, pincushion distortion is lower than barrel distortion with 0.6% being a typical value.

Correcting Pincushion Distortion

Pincushion 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