aberration

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ab·er·ra·tion / ˌabəˈrāshən/ • n. a departure from what is normal, usual, or expected, typically one that is unwelcome. ∎  a person whose beliefs or behavior are unusual or unacceptable. ∎  a departure from someone's usual moral character or mental ability, typically for the worse. ∎  Biol. a characteristic that deviates from the normal type: color aberrations. ∎  Optics the failure of rays to converge at one focus because of limitations or defects in a lens or mirror. ∎  Astron. the apparent displacement of a celestial object from its true position, caused by the relative motion of the observer and the object. DERIVATIVES: ab·er·ra·tion·al / -shənl/ adj.

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aberration, in optics, condition that causes a blurring and loss of clearness in the images produced by lenses or mirrors. Of the many types of aberration, the two most significant to the lens maker are spherical and chromatic. Spherical aberration is caused by the failure of a lens or mirror of spherical section to bring parallel rays of light to a single focus. The effect results from the operation of the laws of optics, not from defects in construction. Spherical aberration can be prevented by using a parabolic rather than a spherical section, but this involves much greater complexity and expense in lens or mirror construction. Chromatic aberration results in the blurred coloring of the edge of an image when white light is sent through a lens. This is caused by the fact that some colors of light are bent, or refracted, more than others after passing through a lens. For example, violet light is bent more than red and thus is brought to a focus nearer the lens than red. No single lens can ever be free of chromatic aberration, but by combining lenses of different types, the effects of the component lenses can be made to cancel one another. Such an arrangement is called an achromatic lens. See reflection; refraction.

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Aberration ★ 1997 (R)

Amy (Gidley) has traveled to her parents remote cabin and notices a lizard infestation. So she heads to the store for some exterminating equipment and meets biologist Marshall (Bossell), who studies eco-abnormalities. Seems the lizards are vicious mutants who eat Amy's cat and are working their way up the food chain. Doesn't offer many scares. 93m/C VHS . AU GB Pamela Gidley, Simon Bossell, Valery (Valeri Nikolayev) Nikolaev; D: Tim Boxell; W: Darrin Oura, Scott Lew; C: Allen Guilford. VIDEO

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aberration In astronomy, apparent slight change of position of a star due to the effect of the Earth's orbital motion and the finite velocity of light. A telescope must be inclined by an angle of up to 20° to compensate for aberration. The effect was first described by James Bradley in 1729 and was used to prove that the Earth orbits the Sun.

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aberration (ab-er-ay-shŏn) n.
1. deviation from the normal.

2. a defect in the image formed by a lens. chromatic a. a defect in which the image has coloured fringes as a result of the different extent to which light of different colours is refracted. spherical a. a defect in which the image is blurred because curvature of the lens causes light rays from the object to come to a focus in slightly different positions.

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aberration In physics, defect in lens and mirror images arising when the incoming light does not fall at or near the centre of the lens or mirror.

Spherical aberration occurs when rays falling on the periphery of a lens or mirror are not brought to the same focus as light at the centre; the image is blurred. Chromatic aberration occurs when the wavelengths of dispersed light are not brought to the same focus; the image is falsely coloured.

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aberration XVI. — L. aberrātiō, -ōn-, f. aberrāre, f. AB- + ERR.
So aberrant XVI.