Abstract

For two flatness requirements involved in the testing of air survey cameras special techniques have been devised.

Photographic plates used for camera calibration should be flat to one or two microns. To achieve this the $\frac{1}{4}\text{-in.}$ plate glass supporting the emulsion is bent flat and held flat during exposure. Flatness is determined in an interferometer using infrared light.

Camera register glass flatness is also checked interferometrically. Since counts of over 100 fringes are required, two monochromatic light sources are used, chosen to produce regular arrangements of black and colored fringes which permit counting by groups.

© 1955 Optical Society of America

Interferometric Control of Grating Ruling with Continuous Carriage Advance*

George R. Harrison and George W. Stroke
J. Opt. Soc. Am. 45(2) 112-121 (1955)

Interferometric Measurement of Wave-Front Aberrations in Gratings and Echelles*

George W. Stroke
J. Opt. Soc. Am. 45(1) 30-35 (1955)

Interferometric Method of Measuring the Spectral Slit Width of Spectrometers*

Vincent J. Coates and Harry Hausdorff
J. Opt. Soc. Am. 45(6) 425-430 (1955)

Fractional-Fringe Measurements with the Corner-Cube Interferometer

Edson R. Peck
J. Opt. Soc. Am. 45(10) 795-797 (1955)

Auxiliary Optical System for Measurement of the Infrared Transmittance of Flat Plates with the Perkin-Elmer 12-C Spectrometer

James R. Jenness
J. Opt. Soc. Am. 45(8) 671-671 (1955)