How Large is a Point Source?

Arthur C. Hardy

doi:10.1364/JOSA.57.000044

Journal of the Optical Society of America
Vol. 57,
Issue 1,
pp. 44-47
(1967)
•https://doi.org/10.1364/JOSA.57.000044

How Large is a Point Source?

Arthur C. Hardy

Not Accessible

Your library or personal account may give you access

Get PDF
Email
Share
Get Citation
Copy Citation Text
Arthur C. Hardy, "How Large is a Point Source?," J. Opt. Soc. Am. 57, 44-47 (1967)

Export Citation
- BibTex
- Endnote (RIS)
- HTML
- Plain Text
Citation alert
Save article

Abstract

A source of light having many times the angular subtense of the sun or moon can usually be treated as a point when making photometric calculations based on the inverse square law. When viewed by the eye, such sources are not perceived as points (like stars) but rather as extended surfaces. In this paper, some typical data on contrast thresholds for targets, both large and small, are converted into threshold stellar magnitudes. This is done for two important cases which, unless carefully distinguished, can lead to erroneous results.

Full Article | PDF Article

More Like This

Visibility of Light Sources Against a Background of Uniform Luminance

Melvin H. Horman
J. Opt. Soc. Am. 57(12) 1516-1521 (1967)

The Visibility of Stars in the Daylight Sky

R. Tousey and E. O. Hulburt
J. Opt. Soc. Am. 38(10) 886-896 (1948)

Optical Performance of the Human Eye

R. W. Gubisch
J. Opt. Soc. Am. 57(3) 407-415 (1967)

Previous Article Next Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (2)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

B₀	0.01	0.1	1	10	100
1000	−2.80	−2.80	−3.03	−4.21	−8.70
100	−0.79	−0.79	−0.85	−1.73	−6.20
10	1.23	1.23	1.20	0.57	−3.72
1	3.09	3.09	3.07	2.60	−1.45
10⁻¹	4.56	4.56	4.56	4.15	0.40
10⁻²	5.45	5.45	5.45	5.09	1.88
10⁻³	5.63	5.63	5.63	5.52	3.11
10⁻⁴	6.55	6.55	6.55	6.53	4.69
10⁻⁵	7.58	7.58	7.58	7.57	6.16

B₀	0.01	0.1	1	10	100
1000	−2.80	−2.89	−5.25	−10.10	−15.10
100	−0.79	−0.85	−2.79	−7.60	−12.60
10	1.23	1.20	−0.38	−5.10	−10.10
1	3.09	3.07	1.94	−2.60	−7.60
10⁻¹	4.56	4.55	3.97	−0.12	−5.10
10⁻²	5.45	5.44	5.28	2.32	−2.61
10⁻³	5.63	5.63	5.61	4.42	−0.15
10⁻⁴	6.55	6.55	6.55	6.13	2.28
10⁻⁵	7.58	7.58	7.58	7.46	4.61

B₀	0.01	0.1	1	10	100
1000	−2.80	−2.80	−3.03	−4.21	−8.70
100	−0.79	−0.79	−0.85	−1.73	−6.20
10	1.23	1.23	1.20	0.57	−3.72
1	3.09	3.09	3.07	2.60	−1.45
10⁻¹	4.56	4.56	4.56	4.15	0.40
10⁻²	5.45	5.45	5.45	5.09	1.88
10⁻³	5.63	5.63	5.63	5.52	3.11
10⁻⁴	6.55	6.55	6.55	6.53	4.69
10⁻⁵	7.58	7.58	7.58	7.57	6.16

B₀	0.01	0.1	1	10	100
1000	−2.80	−2.89	−5.25	−10.10	−15.10
100	−0.79	−0.85	−2.79	−7.60	−12.60
10	1.23	1.20	−0.38	−5.10	−10.10
1	3.09	3.07	1.94	−2.60	−7.60
10⁻¹	4.56	4.55	3.97	−0.12	−5.10
10⁻²	5.45	5.44	5.28	2.32	−2.61
10⁻³	5.63	5.63	5.61	4.42	−0.15
10⁻⁴	6.55	6.55	6.55	6.13	2.28
10⁻⁵	7.58	7.58	7.58	7.46	4.61

Abstract

Cited By

Tables (2)

Journal of the Optical Society of America