Abstract

Some of the light intensity distributions calculated in the first paper of this series have been observed experimentally with the aid of a macroscopic set-up. Because of a peculiarity of the human eye, a degree of contrast which is far from optimum will be satisfactory for practical purposes.

The theoretical investigation begun in the first paper is continued. A measure of contrast is defined by analogy to Michelson’s measure of visibility of fringes. An expression for this is derived for the case of a very narrow phase annulus filled with light except for a narrow zone along each edge.

The possibility of measuring the phase shift introduced by an object, with the aid of phase contrast equipment, is discussed.

© 1950 Optical Society of America

An Extension of Toraldo’s Theory of Phase Contrast I*

L. Ivan Epstein
J. Opt. Soc. Am. 40(5) 291-294 (1950)

Phase Contrast Microscopy for Opaque Specimens*

James R. Benford and Richard L. Seidenberg
J. Opt. Soc. Am. 40(5) 314-316 (1950)

Color Phase-Contrast Microscopy: Requirements and Applications*

Charles Proffer Saylor, Arthur T. Brice, and F. Zernike
J. Opt. Soc. Am. 40(5) 329-334 (1950)

Peripheral Contrast Thresholds of the Human Eye

M. A. Bouman
J. Opt. Soc. Am. 40(12) 825-832 (1950)

A Precision Method for Measuring Small Phase Differences*

F. Zernike
J. Opt. Soc. Am. 40(5) 326-328 (1950)