The determination of contrast thresholds for a human observer was performed by a new method. To the observer targets having increasing contrasts from left to right are presented. The luminances of the targets are chosen such that some of the targets are invisible to the observer. The observer counts the number of visible targets. From this number the contrast threshold can be derived. This method is objective, faster than traditional methods, and gives comparable results. The photometry for the determination of the contrasts is described.

1.
H. R.
Blackwell
,
J. Opt. Sci. Am.
36
,
624
(
1946
).
2.
R.
Seiculer
and
P.
Tynan
,
Am. J. Optom. Physiol. Opt.
8
,
573
(
1977
).
3.
T. E.
Cohn
,
L. N.
Thibos
, and
R. N.
Kleinstein
,
J. Opt. Soc. Am.
64
,
1321
(
1974
).
4.
R. T.
Mennesy
and
W.
Richards
,
J. Opt. Soc. Am.
65
,
97
(
1975
).
5.
J. S.
van Esen
and
S.
Novak
,
J. Opt. Soc. Am.
64
,
726
(
1974
).
6.
E. W.
Campbell
and
D. G.
Green
,
J. Phys.
181
,
576
(
1965
).
7.
F. L.
van Nes
and
M. A.
Bouman
,
J. Opt. Soc. Am.
57
,
401
(
1967
).
8.
J. G.
Robson
,
J. Opt. Soc. Am.
56
,
1141
(
1966
).
9.
K. T.
Rosenbruch
,
Proc. SPIE
46
,
19
(
1974
).
10.
R. L.
Savoy
and
J. J.
McCann
,
J. Opt. Soc. Am.
65
,
343
(
1975
).
11.
T. T.
McCann
,
R. L.
Savoy
, and
J. A.
Hall
,
Vision Res.
18
,
891
(
1978
).
12.
J. J.
McCann
and
J. A.
Hall
, Jr.
,
J. Opt. Soc. Am.
70
,
212
(
1980
).
13.
G. J.
Burton
and
R.
Moorhead
,
J. Opt. Soc. Am.
71
,
1056
(
1981
).
14.
J. Gorraiz (personal communication).
15.
W. E. K. Middleton, Vision Through the Atmosphere (University of Toronto, Toronto, 1958), Fig. 10.1.
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