Image: Magnification power of a loupe

Description: The magnification power of a loupe is given by M=α′α=25 cmf{\displaystyle M={\frac {\alpha '}{\alpha }}={\frac {25\ \mathrm {cm} }{f}}}, where 25 centimeter is the near limit of the normal eye. When the virtual image is not at infinity but at the near point, the angular magnification is M+1.{\displaystyle M+1.}
Title: Magnification power of a loupe
Credit: Own work, from Through Magic Glasses and Other Lectures
Author: Pieter Kuiper and Arabella B. Buckley
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License: Public domain
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