Abstract

The Blackwell data on the positive-contrast thresholds of the human eye have been cross plotted in luminance values and incorporated into a nomogram for determining whether light sources can be seen either with the unaided eye, or with a telescope. The nomogram incorporates data for the two special cases where the light source is in front of, and beyond the source of background luminance; the former is readily applicable to the general cases and the latter is applicable to the important special cases of stars, planets, and other exo-atmospheric sources. The nomogram allows the effects of aberrations, diffraction, defocusing, and transmission losses in a telescope to be taken into account. The effects of aberrations, etc., in the eye itself are discussed.

© 1967 Optical Society of America

How Large is a Point Source?

Arthur C. Hardy
J. Opt. Soc. Am. 57(1) 44-47 (1967)

Signal-light nomogram

Jacqueline I. Gordon, Catharine F. Edgerton, and Seibert Q. Duntley
J. Opt. Soc. Am. 65(2) 111-118 (1975)

Spatial Modulation Transfer in the Human Eye

Floris L. Van Nes and Maarten A. Bouman
J. Opt. Soc. Am. 57(3) 401-406 (1967)

The Visibility of Stars and Planets During Twilight

R. Tousey and M. J. Koomen
J. Opt. Soc. Am. 43(3) 177-183 (1953)

Luminance as a Parameter of the Eye-Movement Control System*

Leon L. Wheeless, Gerald H. Cohen, and Robert M. Boynton
J. Opt. Soc. Am. 57(3) 394-400 (1967)