﻿ Definition of Aplanatic. Meaning of Aplanatic. Synonyms of Aplanatic

# Definition of Aplanatic. Meaning of Aplanatic. Synonyms of Aplanatic

Here you will find one or more explanations in English for the word Aplanatic. Also in the bottom left of the page several parts of wikipedia pages related to the word Aplanatic and, of course, Aplanatic synonyms and on the right images related to the word Aplanatic.

## Definition of Aplanatic

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Aplanatic focus
Focus Fo"cus, n.; pl. E. Focuses, L. Foci. [L. focus hearth, fireplace; perh. akin to E. bake. Cf. Curfew, Fuel, Fusil the firearm.] 1. (Opt.) A point in which the rays of light meet, after being reflected or refrcted, and at which the image is formed; as, the focus of a lens or mirror. 2. (Geom.) A point so related to a conic section and certain straight line called the directrix that the ratio of the distace between any point of the curve and the focus to the distance of the same point from the directrix is constant. Note: Thus, in the ellipse FGHKLM, A is the focus and CD the directrix, when the ratios FA:FE, GA:GD, MA:MC, etc., are all equal. So in the hyperbola, A is the focus and CD the directrix when the ratio HA:HK is constant for all points of the curve; and in the parabola, A is the focus and CD the directrix when the ratio BA:BC is constant. In the ellipse this ratio is less than unity, in the parabola equal to unity, and in the hyperbola greater than unity. The ellipse and hyperbola have each two foci, and two corresponding directrixes, and the parabola has one focus and one directrix. In the ellipse the sum of the two lines from any point of the curve to the two foci is constant; that is: AG+GB=AH+HB; and in the hyperbola the difference of the corresponding lines is constant. The diameter which passes through the foci of the ellipse is the major axis. The diameter which being produced passes through the foci of the hyperbola is the transverse axis. The middle point of the major or the transverse axis is the center of the curve. Certain other curves, as the lemniscate and the Cartesian ovals, have points called foci, possessing properties similar to those of the foci of conic sections. In an ellipse, rays of light coming from one focus, and reflected from the curve, proceed in lines directed toward the other; in an hyperbola, in lines directed from the other; in a parabola, rays from the focus, after reflection at the curve, proceed in lines parallel to the axis. Thus rays from A in the ellipse are reflected to B; rays from A in the hyperbola are reflected toward L and M away from B. 3. A central point; a point of concentration. Aplanatic focus. (Opt.) See under Aplanatic. Conjugate focus (Opt.), the focus for rays which have a sensible divergence, as from a near object; -- so called because the positions of the object and its image are interchangeable. Focus tube (Phys.), a vacuum tube for R[oe]ntgen rays in which the cathode rays are focused upon the anticathode, for intensifying the effect. Principal, or Solar, focus (Opt.), the focus for parallel rays.

## Meaning of Aplanatic from wikipedia

- quality of images produced by optical systems. A spherical lens has an aplanatic point (i.e., no spherical aberration) only at a radius that equals the...
- An aplanatic lens is a lens that is free of both spherical and coma aberrations. Aplanatic lenses can be made by combining two or three lens elements...
- light source that is surrounded by a blue and red color at its edges. The aplanatic condenser is corrected for spherical aberration. The compound achromatic...
- Clarity grading by WJC standards is by examination using a 10x achromatic, aplanatic loupe in normal light. The American Gem Society grades clarity on a number...
- and coma are minimized at a single wavelength are called bestform or aplanatic lenses. Vertical coma is the most common higher-order aberration in the...
- Optical System Aplanatic Gregorian f/9 Focal Length 16.48 m Primary Mirror f/1.0, Diameter 1.83 m Secondary Mirror f/0.9, Diameter 0.38 m (Focus Control:...
- X. Chen, "A complete and com****tionally efficient numerical model of aplanatic solid immersion lens scanning microscope," Opt. Express 21, 14316-14330...
- perfecting the microscope, and in the process, discovered the Law of Aplanatic Foci, building a microscope where the image point of one lens coincided...
- fulfilling this condition and free from spherical aberration is called aplanatic (Gr**** a-, privative, plann, a wandering). This word was first used by...
- ISBN 978-0-07-138201-4. Sacek, Vladimir (July 14, 2006). "8.2.2 Cl****ical and aplanatic two-mirror systems". Notes on AMATEUR TELESCOPE OPTICS. Retrieved 2009-06-22...