crown lens

American  

noun

Optics.

1. a lens made of crown glass, usually used as the converging lens component of an achromatic lens.

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crown lens British  

noun

1. a lens made of optical crown, esp the optical-crown part of a compound achromatic lens

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Etymology

Origin of crown lens

First recorded in 1825–35

Example Sentences

What Hall and Dollond did was to make the outer or crown lens of the objective as before, and place behind it a plano-concave lens of dense flint glass.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck

Fitted with a reversible crown lens for photography.

From A Popular History of Astronomy During the Nineteenth Century Fourth Edition by Clerke, Agnes M. (Agnes Mary)

It will be seen that the flint glass component by itself is a concave lens and therefore neutralises in part, or in whole, the convex crown lens.

From Optical Projection Part 1: Projection of Lantern Slides by Wright, Lewis

This had the effect of neutralizing the chromatic effect, or color aberration, while at the same time only part of the refractive effect of the crown lens was destroyed.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck