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Pos′i-tive eye-piece.

A combination of lenses at the eye end of a telescope or microscope, consisting of two plano-convex lenses in which the convex sides of the glasses are turned toward each other. See negative eye-piece.

Its principal use is in the micrometer, and it is often called the micrometer eye-piece, being used to measure a magnified image.

The lenses are separated by a distance a little less than the focal distance of the one nearest to the eye, the image of the object being viewed beyond both lenses.

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