Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The Magnification of Conic Mirror Reflectometers



K A. Snail, Leonard Hanssen


Conic mirror reflectometers are used to measure the diffuse reflectance and total integrated scatter of surfaces. In spite of the long history of using conic mirrors for these purposes, the maximum magnification of the three primary types of conic mirrors [hemisphere, hemi-ellipsoid, & dual-paraboloid] has not been previously compared quantitatively. In fact, only for the hemi-ellipsoid has an exact formulation of the magnification been published. The maximum magnification is needed to properly size detectors and radiation sources used with reflectometers. In this paper, exact analytic expressions for the maximum magnification of both a Coblentz hemisphere and a dual paraboloid mirror system are derived and compared with the well-known expression for a hemi-ellipsoidal mirror.
Applied Optics


Coblentz hemisphere, diffuse reflectance, total integrated scatter


Snail, K. and Hanssen, L. (1998), The Magnification of Conic Mirror Reflectometers, Applied Optics, [online], (Accessed July 13, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 30, 1998, Updated October 12, 2021