On cosine-fourth and vignetting effects in real lenses

M. Aggarwal, Hong Hua, N. Ahuja

Research output: Chapter in Book/Report/Conference proceedingConference contribution

29 Citations (Scopus)

Abstract

This paper has been prompted by observations of disparities between the observed fall-off in irradiance for off-axis points and that accounted for by the cosine-fourth and vignetting effects. A closer examination of the image formation process for real lenses revealed that even in the absence of vignetting a point light source does not uniformly illuminate the aperture, an effect known as pupil aberration. For example, we found the variation for a 16mm lens to be as large as 31% for a field angle of 10°. In this paper, we critically evaluate the roles of cosine-fourth and vignetting effects and demonstrate the significance of the pupil aberration on the fall-off in irradiance away from image center. The pupil aberration effect strongly depends on the aperture size and shape and this dependence has been demonstrated through two sets of experiments with three real lenses. The effect of pupil aberration is thus a third important cause of fall in irradiance away from the image center in addition to the familiar cosine-fourth and vignetting effects, that must be taken into account in applications that rely heavily on photometric variation such as shape from shading and mosaicing.

Original languageEnglish (US)
Title of host publicationProceedings of the IEEE International Conference on Computer Vision
Pages472-479
Number of pages8
Volume1
StatePublished - 2001
Externally publishedYes
Event8th International Conference on Computer Vision - Vancouver, BC, United States
Duration: Jul 9 2001Jul 12 2001

Other

Other8th International Conference on Computer Vision
CountryUnited States
CityVancouver, BC
Period7/9/017/12/01

Fingerprint

Aberrations
Lenses
Light sources
Image processing
Experiments

ASJC Scopus subject areas

  • Computer Vision and Pattern Recognition
  • Software

Cite this

Aggarwal, M., Hua, H., & Ahuja, N. (2001). On cosine-fourth and vignetting effects in real lenses. In Proceedings of the IEEE International Conference on Computer Vision (Vol. 1, pp. 472-479)

On cosine-fourth and vignetting effects in real lenses. / Aggarwal, M.; Hua, Hong; Ahuja, N.

Proceedings of the IEEE International Conference on Computer Vision. Vol. 1 2001. p. 472-479.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Aggarwal, M, Hua, H & Ahuja, N 2001, On cosine-fourth and vignetting effects in real lenses. in Proceedings of the IEEE International Conference on Computer Vision. vol. 1, pp. 472-479, 8th International Conference on Computer Vision, Vancouver, BC, United States, 7/9/01.
Aggarwal M, Hua H, Ahuja N. On cosine-fourth and vignetting effects in real lenses. In Proceedings of the IEEE International Conference on Computer Vision. Vol. 1. 2001. p. 472-479
Aggarwal, M. ; Hua, Hong ; Ahuja, N. / On cosine-fourth and vignetting effects in real lenses. Proceedings of the IEEE International Conference on Computer Vision. Vol. 1 2001. pp. 472-479
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