pincushion distortion,
1 inward bowing of gridded straight lines in an image as a result of lens distortion.
2 the image of a square object thus resembling a pincushion or pillow.
3 a distortion of a fluoroscopic image associated with the use of image intensifier tubes. See also barrel distortion.
distortion
Aberration of an optical system resulting in an image which does not conform to the shape of the object, somewhat resembling the image viewed through a cylindrical lens. This is due to an unequal magnification of the image. Distortion can be barrel-shaped (barrel-shaped distortion) in which the corners of the image of a square are closer to the centre than the middle part of the sides; or pincushion (pincushion distortion) in which the corners of the image of a square are farther from the centre than the middle part of the sides (Fig. D10). Example of barrel-shaped distortion: a square object seen through an uncorrected negative spectacle lens. Example of pincushion distortion: a square object seen through an uncorrected positive spectacle lens. See correction; fisheye lens; sine condition.
)
Fig. D10 Distortion (O, object; A, pincushion distortion; B, barrel-shaped distortion)
Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content.
| ?Page tools | ||
|---|---|---|
|