pincushion distortion


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Related to pincushion distortion: Barrel Distortion

pincushion distortion

irregular image produced when axial magnification is greater than peripheral magnification. See: Petzval surface.

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.

pin·cush·i·on dis·tor·tion

(pin'kush-ŭn dis-tōr'shŭn)
Irregular image produced when axial magnification is greater than peripheral magnification.
See: Petzval surface

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)enlarge picture
Fig. D10 Distortion (O, object; A, pincushion distortion; B, barrel-shaped distortion)
References in periodicals archive ?
Zoom lenses tend to produce barrel distortion at wide-angle positions and pincushion distortion at telephoto positions (due to slight changes in distortion characteristics during zooming).
Sweeping the Moon out of the field, I could detect the very slight pincushion distortion inherent in the Ethos design--something I didn't perceive when sweeping across star fields.
Examining the Nikon we noted no astigmatism, curvature of field, rolling distortion, or pincushion distortion.
95) sports an impressive 65[degrees] field of view that is free of pincushion distortion and field curvature out to the edges, and a comfortable 19 mm of eye relief.