Optical aberration

Optical aberration - Factbites
Where results make sense
About us | Why use us? | Reviews | PR | Contact us

Topic: Optical aberration

Note: these results are not from the primary (high quality) database.

In the News (Sat 4 Jul 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Nikon MicroscopyU: Water Immersion Objectives
		Spherical aberration caused by the mismatch of refractive indices in the optical path is the primary cause of the image deterioration, and this aberration increases proportionally with imaging depth.
		Optical correction is optimized for the light distribution in a homogeneous medium adjacent to the cover glass, although in practice, the observation volume may be some distance away, and the distribution of light is dramatically affected by refractive index differences and by the distance of the focal plane from the glass.
		Imaging a specimen plane that is separated from the cover glass by a region of aqueous medium is representative of the optical conditions that prevail in thick biological specimen studies, and the image deterioration encountered is a primary incentive for the employment of water immersion objectives.
	www.microscopyu.com /articles/optics/waterimmersionobjectives.html (4773 words)

	Aberration in optical systems - Wikipedia, the free encyclopedia
		Aberration in optical systems (lenses, prisms, mirrors or series of them intended to produce a sharp image) generally leads to blurring of the image.
		Spherical aberration and changes of the sine ratios are often represented graphically as functions of the aperture, in the same way as the deviations of two astigmatic image surfaces of the image plane of the axis point are represented as functions of the angles of the field of view.
		The aberrations of the third order are: (1) aberration of the axis point; (2) aberration of points whose distance from the axis is very small, less than of the third order -- the deviation from the sine condition and coma here fall together in one class; (3) astigmatism; (4) curvature of the field; (5) distortion.
	en.wikipedia.org /wiki/Aberration_in_optical_systems (5764 words)

	Clinical Applications of the Shack-Hartmann Aberrometer
		Aberrations and/or calibration errors of the optical components of the measurement system itself were determined by replacing the light trap T with a mirror and expanding the adjustable stop S in order to reflect a plane wave through the system.
		has been developed extensively by astronomers for measuring the optical aberrations of the atmosphere which interfere with terrestrial telescopes.
		Optical quality of this eye is poor as indicated by the distortion of the matrix of dots in the central region and by the poor quality of individual dots in the SH data image (A).
	research.opt.indiana.edu /Library/SHclinical/SHclinical.html (6201 words)

	LA Sight 877-828-2020 dedicated to excellence in LASIK eye surgery,cataract care and consultative ophthalmology,Lasik eye surgery Los Angeles,Lasik surgeon California,Lasik
		In an optical context, altering the curvature of a lens to adjust or correct for spherical aberration.
		Aberrations can be regular and measurable, such as spherical aberration, chromatic aberration, and coma; or can be irregular, as might be noticed when looking through a pane of handblown glass.
		A lens aberration, resulting from different magnifications in the various lens zones, that occurs in that part of the image field that is some distance from the principal axis of the system.
	la-lasik.com /LS_glossary.asp (2775 words)

	aberration -- Encyclopædia Britannica
		There are three basic types of optical telescopes: refractors that use lenses, reflectors that use mirrors, and catadioptrics that use a combination of both lenses and mirrors.
		The change of image distance with wavelength is known as chromatic aberration, and the variation of magnification with wavelength is known as...
		Spherical aberration is present when the outer parts of a lens do not bring light rays into the same focus as...
	www.britannica.com /eb/article-9003333 (720 words)

	eMedicine - LASIK, Future Advances : Article by Christopher Yo, MD, PhD
		Optical aberration is increased because the normal cornea is prolate in shape (steeper in the center), but it becomes oblate (steeper in the periphery) after successful conventional laser ablation profile.
		If optical aberrations in the eye could be eliminated, the theoretical limit of foveal acuity would be 20/12 for a small pupil and up to 20/5 for a dilated pupil.
		Image degradation occurs after conventional laser treatment on the cornea because optical aberration is increased after surgery, especially at night when the pupil is in a dilated state.
	www.emedicine.com /oph/topic759.htm (4763 words)

	A.xml
		The amount of spherical aberration varies with the location of the object point and, for any particular point, is approximately proportional to the square of the distance of the outermost rays from the optical axis.
		Longitudinal chromatic aberration produces a sequence of overlapping differently colored points parallel to the optical axis; transverse chromatic aberration produces a similar sequence of points along a line across (transverse to) the axis.
		In the absence of other kinds of aberration, chromatic aberration causes the separation of a white point in object space into a sequence of overlapping monochromatic points in image space, with the violets closest to the lens and the reds farthest from the lens.
	www.ngs.noaa.gov /PUBS_LIB/GEOID/Droman_papers/glossary/xml/A.xml (13264 words)

	Optical Design Software Overview
		Aberration coefficients are useful in optical design because they characterize the system in terms of its symmetries, because they allow the overall performance to be expressed as a sum of surface contributions, and because they are calculated quickly.
		In the case of the chromatic aberrations, the primary and secondary chromatic aberration of the axial and chief rays are computed.
		The form in which aberrations are displayed depends on the program and the type of system under study, but as a general rule, for focal systems aberrations are displayed as equivalent ray displacements in the paraxial image plane.
	www.sinopt.com /learning1/optsoft/evaluation/evaluation.htm (3682 words)

	Olympus Microscopy Resource Center: Anatomy of the Microscope - Objective Magnification in Infinity Optical Systems: Interactive Java Tutorial
		Infinity-corrected microscope optical systems are designed to enable the insertion of auxiliary devices, such as vertical illuminators and intermediate tubes, into the optical pathway between the objective and eyepieces without introducing spherical aberration, requiring focus corrections, or creating other image problems.
		In a finite optical system of fixed tube length, light passing through the objective is directed toward the intermediate image plane (located at the front focal plane of the eyepiece) and converges at that point, undergoing constructive and destructive interference to produce an image.
		The situation is quite different for infinity-corrected optical systems where the objective produces a flux of parallel light wavetrains imaged at infinity (often referred to as infinity space, and labeled in the tutorial window), which are brought into focus at the intermediate image plane by the tube lens.
	www.olympusmicro.com /primer/java/infinityoptics/magnification (981 words)

	Chromatic Aberration: Optical: Glossary: Learn: Digital Photography Review
		Chromatic aberration or "color fringing" is caused by the camera lens not focusing different wavelengths of light onto the exact same focal plane (the focal length for different wavelengths is different) and/or by the lens magnifying different wavelengths differently.
		Chromatic aberration is visible as color fringing around contrasty edges and occurs more frequently around the edges of the image frame in wide angle shots.
		Although the above chromatic aberrations can be purple in color under certain circumstances, "Purple Fringing" usually refers to a typical digital camera phenomenon that is caused by the microlenses.
	www.dpreview.com /learn/key=chromatic+aberration (269 words)

	About Coma
		The dominant optical aberration in the Newtonian telescope is off-axis coma.
		When observing planets the optical performance of the telescope is diffraction limited as long as the planet is held near the center of the fov.
		Usually, these eyepiece aberrations are larger than the telescope’s comatic aberration and they are the aberrations most prominent in the image.
	www.opticalmechanics.com /about_coma.htm (1924 words)

	A Statistical Model of the Aberration Structure of Normal, Well-Corrected Eyes
		A statistical model of the wavefront aberration function of the normal, well-corrected eye was constructed based on normative data from 200 eyes which show that, apart from spherical aberration, the higher-order aberrations of the human eye tend to be randomly distributed about a mean value of zero.
		Since we were interested primarily in the higher-order aberrations of the eye, we paralyzed accommodation and corrected the sphero-cylindrical refractive errors with trial lenses.
		The vector of Zernike aberration coefficients describing the aberration function for any individual eye was modeled as a multivariate, Gaussian, random variable with known mean, variance, and covariance.
	research.opt.indiana.edu /Library/statModel/statModel.html (2937 words)

	Seidel vs. Zernike
		The Seidel aberrations were developed in the mid 19th century to account for the monochromatic geometrical aberrations of centered optical systems, i.e.
		The aberration polynomial coefficients can be found either from a series expansion of the law of refraction, or using an iteration procedure introduced by Buchdahl[4], which considers rotational invariants and builds upon low-order coefficients to develop the next higher-order coefficients.
		The magnitude of the aberrations is expressed in terms of an aberration polynomial.
	www.sinopt.com /learning1/desnotes/seizern.htm (818 words)

	The Hutchinson Dictionary of Science: aberration, optical@ HighBeam Research
		The Hutchinson Dictionary of Science: aberration, optical@ HighBeam Research
		Aberration occurs because of minute variations in lenses and mirrors, and because different parts of the light spectrum are reflected or refracted by varying amounts.
		In chromatic aberration the image is surrounded by coloured fringes, because light of different colours is brought to different focal points by a lens.
	highbeam.com /library/doc0.asp?DOCID=1P1:28917723&... (184 words)

	Optical Response to LASIK Surgery for Myopia from Total and Corneal Aberration Measurements -- Marcos et al. 42 (13): 3349 -- Investigative Ophthalmology & Visual Science
		Optical Response to LASIK Surgery for Myopia from Total and Corneal Aberration Measurements -- Marcos et al.
		The deviations from the principal ray are proportional to the local derivatives of the wave aberration.
		assessed by the modification of its spherical aberration.
	www.iovs.org /cgi/content/full/42/13/3349 (5041 words)

	Information: Telescopes Microscopes Night Vision Binoculars Digital Cameras Rifle Scopes Radar Guns, & more!
		aberration, optical Errors in an optical system, lens or mirror, affecting the image. The six types of aberration are astigmatism, chromatic, coma, distortion, field curvature and spherical.
		anastigmat (ic) An optical system with at least three elements completely corrected for “spherical aberration,” “coma,” and “astigmatism” (which see).
		infinity corrected optics In microscopy, an optical design in which the rays passing through the objective do not converge to form an image in the eyepiece without the assistance of additional optics in the drawtube. As the rays remain parallel, they are said to continue to infinity.
	www.opticsplanet.com /info/glossary.shtml (6231 words)

	IU School of Optometry: A. Bradley
		The continuous optical image created at the retina is immediately packaged into discrete samples of neural activity by the photoreceptors, and the sampling process continues on throughout the visual system.
		Clinical implications of decentering the optical beam in the pupil.
		Ye, M., Bradley, A., Zhang, X., Thibos, L.N. (1992) The effect of pupil size on chromostereopsis and chromatic diplopia: Interaction between the Stiles-Crawford Effect and chromatic aberration.
	www.opt.indiana.edu /people/faculty/bradley.htm (2617 words)

	Coatings Control Aberration in Optical Pickups - November, 2000
		The solution has been to introduce aberrations into the plastic lenses in the optical pickups, but this can be costly and time-consuming.
		The demand for more-compact optical disk drives in laptops has created a problem: The shorter image-to-object distances result in astigmatism.
		The coatings had a negligible effect on third-order coma and spherical aberration.
	www.photonics.com /spectra/tech/XQ/ASP/techid.943/QX/read.htm (178 words)

	Book List Index
		Optical Resonance and the Two-Level Atom Allen and Eberly, John Wiley & Sons
		Radiometry and the Detection of Optical Radiation Boyd, Wiley & Sons
		Optical Waves in Crystals Yariv and Yeh, John Wiley & Sons, Inc.
	www.opticsnotes.com /books.htm (750 words)

	Spherical aberration - Wikipedia, the free encyclopedia
		In optics, spherical aberration is an image imperfection that occurs due to the increased refraction of light rays that occurs when rays strike a lens or mirror near its edge, in comparison with those that strike nearer the center.
		It is often considered to be an imperfection of telescopes and other instruments which makes their focusing less than ideal due to the spherical shape of lenses and mirrors.
		Because of spherical aberration, telescopes shorter than f/10 are usually made with non-spherical mirrors or with correcting lenses.
	en.wikipedia.org /wiki/Spherical_aberration (258 words)

	Aberration in optical systems - Wikipedia, the free encyclopedia
		Aberration in optical systems (lenses, prisms, mirrors or series of them intended to produce a sharp image) generally leads to blurring of the image.
		Spherical aberration and changes of the sine ratios are often represented graphically as functions of the aperture, in the same way as the deviations of two astigmatic image surfaces of the image plane of the axis point are represented as functions of the angles of the field of view.
		The most important is the chromatic difference of aberration of the axis point, which is still present to disturb the image, after par-axial rays of different colours are united by an appropriate combination of glasses.
	en.wikipedia.org /wiki/Aberration_in_optical_systems (5768 words)

	aberration -- Encyclopædia Britannica
		in optical systems, such as lenses and curved mirrors, the deviation of light rays through lenses, causing images of objects to be blurred.
		The change of image distance with wavelength is known as chromatic aberration, and the variation of magnification with wavelength is known as...
		There are three basic types of optical telescopes: refractors that use lenses, reflectors that use mirrors, and catadioptrics that use a combination of both lenses and mirrors.
	www.britannica.com /eb/article-9003333 (769 words)

	Nikon MicroscopyU: Infinity Optical Systems
		In a finite optical system of fixed tube length, light passing through the objective is directed toward the intermediate image plane (located at the front focal plane of the eyepiece) and converges at that point, undergoing constructive and destructive interference to produce an image (Figure 2(a)).
		The situation is quite different for infinity-corrected optical systems where the objective produces a flux of parallel light wavetrains imaged at infinity (often referred to as infinity space; Figure 2(b)), which are brought into focus at the intermediate image plane by the tube lens.
		Another consideration is the objective pupil diameter, which also must be increased for optimum performance with low-magnification objectives in optical systems having long tube lens focal lengths.
	www.microscopyu.com /articles/optics/cfintro.html (2190 words)

	Olympus Microscopy Resource Center: Anatomy of the Microscope - Focus Depth and Spherical Aberration - Interactive Java Tutorial
		Cross-sections taken along the optical axis of the microscope near the focal plane using a high numerical aperture objective with spherical aberration are illustrated in Figure 1.
		Instead, the wavefront is distorted and departs from ideal behavior in a manner that is dependent upon the nature of the aberration and/or image filters and conditions that are present in the optical system.
		Furthermore, distortion introduced by spherical aberration may not only affect image quality and fidelity, which affect interpretation and measurement of the specimen, but also the efficiency of confocal and other imaging modes in which the microscope optics are used to reduce the image to obtain a diffraction-limited illuminating point.
	www.olympusmicro.com /primer/java/aberrations/pointspreadaberration (1297 words)

	Mirror article - Mirror reflective plane parallel light mirror image parabolic concave - What-Means.com
		Note that spherical concave and convex mirrors do not have a single focal point, as often erroneously described in high school physics text books (see spherical aberration in Lens (optics) and Aberration in optical systems).
		The reflectivity of the mirror coating depends somewhat on the wavelength of light, and this is exploited in some optical work to make cold and hot mirrors.
		These are glass (or sometimes other material) substrates on which one or more layers of dielectric material are deposited, to form an optical coating.
	www.what-means.com /encyclopedia/Mirror (907 words)

	Aberration Invariant Optical/Digital Incoherent Optical Systems
		By optimum combination of optical pre-processing and digital post-processing, or optical coding and digital decoding of the image information, incoherent optical systems invariant to numerous aberrations can be formed.
		Systems that are invariant to misfocus are also invariant to chromatic aberration, astigmatism, thermal effects, and spherical aberration.
		The theory of aberration invariance can also be used with low-cost, low-precision optics to produce systems that image with the performance of high-cost, high-precision, or near diffraction-limited, spatial resolution.
	www.cdm-optics.com /wave/pubs/papers/overview/paper.html (668 words)

	A Glossary for Telescope Buyers and Users
		A marketing term for an optical system in which every optical surface where light passes from glass into air, or from air into glass, is coated with one of the newer, high-tech low-reflection coatings, which transmit more light than such earlier ones as magnesium fluoride.
		A marketing term for an optical system in which every optical surface where light passes from glass into air, or from air into glass, is coated with one of the early low-reflection coatings, almost certainly magnesium fluoride.
		An achromat will also have spherical aberration corrected at one wavelength of light -- usually green.
	observers.org /beginner/glossary.html (11783 words)

	Nikon MicroscopyU: Microscope Optical Systems
		Condenser Image Planes - In a microscope optical system, the lamp filament is imaged in the focal plane of the condenser aperture diaphragm when the microscope is configured to operate under conditions of Köhler illumination.
		Microscope Conjugate Field Planes - In a microscope optical system, the lamp filament is imaged in the focal plane of the condenser aperture diaphragm when the microscope is configured to operate under conditions of Köhler illumination.
		Perfect Two-Lens System Characteristics - During investigations of a point source of light that does not lie in the focal plane of a lens, it is often convenient to represent a perfect lens as a system composed of two individual lens elements.
	www.microscopyu.com /articles/optics/opticshome.html (1867 words)

	Aberration - Wikipedia, the free encyclopedia
		4.2 Aberration in optical systems, see also the article on lenses.
		Aberration (Latin ab, from or away + errare, to wander), a deviation or wandering, especially used in the figurative sense as:
		4.1 Aberration of light, also referred to as astronomical aberration or stellar aberration.
	en.wikipedia.org /wiki/Aberration (126 words)

Try your search on: Qwika (all wikis)

Topic: Optical aberration

Ads by Google

Related Topics

In the News (Sat 4 Jul 09)