Aperture referral in dioptric systems with stigmatic elements

A previous paper develops the general theory of aperture referral in linear optics and shows how several ostensibly distinct concepts, including the blur patch on the retina, the effective corneal patch, the projective field and the field of view, are now unified as particular applications of the g...

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Main Author: W. F. Harris
Format: Article
Language:English
Published: AOSIS 2012-12-01
Series:African Vision and Eye Health
Subjects:
Online Access:https://avehjournal.org/index.php/aveh/article/view/60
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author W. F. Harris
author_facet W. F. Harris
author_sort W. F. Harris
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description A previous paper develops the general theory of aperture referral in linear optics and shows how several ostensibly distinct concepts, including the blur patch on the retina, the effective corneal patch, the projective field and the field of view, are now unified as particular applications of the general theory.  The theory allows for astigmatism and heterocentricity.  Symplecticity and the generality of the approach, however, make it difficult to gain insight and mean that the material is not accessible to readers unfamiliar with matrices and linear algebra. The purpose of this paper is to examine whatis, perhaps, the most important special case, that in which astigmatism is ignored.  Symplecticity and, hence, the mathematics become greatly simplified. The mathematics reduces largely to elementary vector algebra and, in some places, simple scalar algebra and yet retains the mathematical form of the general approach.  As a result the paper allows insight into and provides a stepping stone to the general theory.  Under referral an aperture under-goes simple scalar magnification and transverse translation.  The paper pays particular attention to referral to transverse planes in the neighbourhood of a focal point where the magnification may be positive, zero or negative.  Circular apertures are treated as special cases of elliptical apertures and the meaning of referred apertures of negative radius is explained briefly. (S Afr Optom 2012 71(1) 3-11)
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spelling doaj.art-157b8d7cfca04fc3be5ec13803842a662022-12-21T23:51:12ZengAOSISAfrican Vision and Eye Health2413-31832410-15162012-12-0171131110.4102/aveh.v71i1.6030Aperture referral in dioptric systems with stigmatic elementsW. F. Harris0Department of Optometry, University of JohannesburgA previous paper develops the general theory of aperture referral in linear optics and shows how several ostensibly distinct concepts, including the blur patch on the retina, the effective corneal patch, the projective field and the field of view, are now unified as particular applications of the general theory.  The theory allows for astigmatism and heterocentricity.  Symplecticity and the generality of the approach, however, make it difficult to gain insight and mean that the material is not accessible to readers unfamiliar with matrices and linear algebra. The purpose of this paper is to examine whatis, perhaps, the most important special case, that in which astigmatism is ignored.  Symplecticity and, hence, the mathematics become greatly simplified. The mathematics reduces largely to elementary vector algebra and, in some places, simple scalar algebra and yet retains the mathematical form of the general approach.  As a result the paper allows insight into and provides a stepping stone to the general theory.  Under referral an aperture under-goes simple scalar magnification and transverse translation.  The paper pays particular attention to referral to transverse planes in the neighbourhood of a focal point where the magnification may be positive, zero or negative.  Circular apertures are treated as special cases of elliptical apertures and the meaning of referred apertures of negative radius is explained briefly. (S Afr Optom 2012 71(1) 3-11)https://avehjournal.org/index.php/aveh/article/view/60aperture referralstigmatic systemsblur patcheffective corneal patchfield of viewprojective field
spellingShingle W. F. Harris
Aperture referral in dioptric systems with stigmatic elements
African Vision and Eye Health
aperture referral
stigmatic systems
blur patch
effective corneal patch
field of view
projective field
title Aperture referral in dioptric systems with stigmatic elements
title_full Aperture referral in dioptric systems with stigmatic elements
title_fullStr Aperture referral in dioptric systems with stigmatic elements
title_full_unstemmed Aperture referral in dioptric systems with stigmatic elements
title_short Aperture referral in dioptric systems with stigmatic elements
title_sort aperture referral in dioptric systems with stigmatic elements
topic aperture referral
stigmatic systems
blur patch
effective corneal patch
field of view
projective field
url https://avehjournal.org/index.php/aveh/article/view/60
work_keys_str_mv AT wfharris aperturereferralindioptricsystemswithstigmaticelements