Abstract

It is shown theoretically that in telephotometry in a foggy atmosphere, large errors may arise from the scattering of light by the fog into the telephotometer. These errors depend both on the angular aperture of the telephotometer and on the half-angle of the cone of air illuminated by the distant lamp. Some experimental results are given, which show even larger errors than the hypothetical atmospheres chosen for theoretical investigation.

© 1949 Optical Society of America

A Photoelectric Method of Measuring the Atmospheric Attenuation of Brightness Contrast Along a Horizontal Path for the Visible Region of the Spectrum*

Howard S. Coleman, Fred J. Morris, Harold E. Rosenberger, and Marshall J. Walker
J. Opt. Soc. Am. 39(7) 515-521 (1949)

The General Theory of Isoplanatism for Finite Aperture and Field

Mario Di Jorio
J. Opt. Soc. Am. 39(4) 305-319 (1949)

X-Ray Optics: The Production of Converging Beams by Total Reflection

W. Ehrenberg
J. Opt. Soc. Am. 39(9) 741-746 (1949)

Sunlight and Skylight as Determinants of Photographic Exposure. II. Scene Structure, Directional Index, Photographic Efficiency of Daylight, Safety Factors, and Evaluation of Camera Exposure

Loyd A. Jones and H. R. Condit
J. Opt. Soc. Am. 39(2) 94-135 (1949)

Contrast Discrimination Charts for Demonstrating the Effect of Anoxia on Vision*

Selig Hecht, Charles D. Hendley, Sylvia Frank, and Simon Shlaer
J. Opt. Soc. Am. 39(11) 922-923 (1949)