Dictionary.com
Thesaurus.com
Showing results for entrance pupil. Search instead for entrance reviews.

entrance pupil

American  

noun

Optics.

  1. the image of the aperture viewed from the objective of an optical system limiting the rays that enter the system.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The iris in the eye dilates and constricts, acting as an entrance pupil.

From Textbooks • Aug. 12, 2015

This distance replaces the angle u in the preceding considerations; and the aperture, i.e. the radius of the entrance pupil, is its maximum value.

From The Project Gutenberg Encyclopedia Volume 1 of 28 by Project Gutenberg

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.