plano-concave

American  

[pley-noh-kon-keyv, -kon-keyv] / ˌpleɪ noʊˈkɒn keɪv, -kɒnˈkeɪv /

adjective

Optics.

1. pertaining to or noting a lens that is plane on one side and concave on the other.

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plano-concave British  

/ ˌpleɪnəʊˈkɒnkeɪv /

adjective

1. (of a lens) having one side concave and the other side plane

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Etymology

Origin of plano-concave

First recorded in 1685–95; plano- ¹ + concave

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

Galileo’s telescope consisted of two lenses—one plano-convex, the other plano-concave, the latter being held next the eye.

From The Astronomy of Milton's 'Paradise Lost' by Orchard, Thomas Nathaniel

A. Thoma's Model, plano-concave, with handle adapted for clamping immediately to the knife carrier of the microtome, in box.

From Microscopes and Accessory Apparatus Catalogue No. 40 by Leitz, Ernst

There, two lenses were made, one plano-convex, and the other plano-concave, and these were placed in a tube made of sheet copper.

From Little Journeys to the Homes of the Great - Volume 12 Little Journeys to the Homes of Great Scientists by Hubbard, Elbert

The chromatic combination consists of a convex lens of crown backed by a concave, or plano-concave, lens of flint.

From Pleasures of the telescope An Illustrated Guide for Amateur Astronomers and a Popular Description of the Chief Wonders of the Heavens for General Readers by Serviss, Garrett Putman