either of two points on the axis of a lens or other optical system, determined by extending an incident oblique ray and the corresponding refracted ray to the axis for the pair of rays that are parallel outside the optical system.
Origin of nodal point
First recorded in 1835–45
Also called node.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
One of the two points in a compound optical system, located so that a light ray directed through the first point will leave the system through the second point, parallel to its original direction.axial point
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.