Theatre Design & Technology - May 1969 - 8

the adaptive process may function in cir
cumstances other than those in the scientific laboratory. But there have been no
studies made of light adaptation in any environment which would even approximate a
theatre. 19 The kind of experience one encounters when walking from a building into
bright sunlight or turning on a lamp in the
middle of the night may be quite different
from the experience one encounters when
the stage lights are suddenly raised after
the audience has sat in darkness for several
seconds.
Although the eye does adapt in conditions
less confined than those of the research
laboratory (for instance, on enco~ntering direct sunlight), to imply that laboratory research under a wide variety of seeing conditions has relevance to theatrical lighting
may be an over-generalization. The difference in variables between laboratory test
conditions and those in the theatre would
make any concrete statement about the
adaptative process nearly impossible. In
the first place, seldom, if ever, do the preadapting conditions in the theatre conform
to those of published test situations. Even
though "numerical investigation indicates
that in most practical cases the effect of involuntary eye movements on foveal adaptation is negligible," 20 when considering the
theatre, one must also be concerned with
the added variable of voluntary eye movements.
In addition, the pupil of the eye plays a role
relative to increase or decrease of iluminiation. "The pupil of the eye varies in size
and, though the variation has an effect small
in comparison with the retinal sensitivity
variation, it is a factor to be taken into account in any practical application of th a result. 2' Original studies in light adaptation
were able to sidestep this problem because
they employed a limited and controlled
visual field, which permitted the use of an
artificial pupil. When an artificial pupil was
not utilized, an incident angl e of illumination
smaller than the smallest diameter of the
pupil was employed. Obviously, such test
methods are invalid under theatrical conclitions.

even though frequent studies of adaptation
have been made, the need for further study
in these areas has not decreased. CommentII1g on past experiments on isual adaptation, Mr. Pickard indicated "that there is no
general agreement
.Only vague compansons can be made between different observers' results." 23 The case seems still
th e same. The matter IS compl icawd even
further by observations that "the results
for the adaptation factor show that even
among apparently normal persons there is a
Wide variation in the extent to which light
adaptatiun deplesses the sensitivity.' 24 A
person can experience the phenomenon of
visual adaptation simply as a resul t of a
long day's eye strain, withou regard to the
actual intensity of stage lights or time
spent in the dark. One could quite easily
conclude that whether or not visual adaptation takes place in the theatre is dependent
not on conditions in the theatre, but rathel
on the conditions of the audience member's
eyes when he arrives. It is, therefore, possible that stage lighting bears a correlative
relationship to visual adaptation, but not a
causative relationship. The only way that the
theory of light adaptation could honestly be
said to apply to theatrical lighting would be
as a result of testing for adaptation in the
theatre. Until that task is accomplished we
must regard visual adaptation in the theatre
as an unproven hypothesis.

7. There IS a good deal of amblgUll\ and unre
Ilab'" y In measures of threshold which have becQm p
apparent in recent analyses of research on 5ublimlnaf
stimulation.
8. Distance from the stage, preconditlonal illumlna
lion, size, shape, movement of objects, etc., all are
variables relevant to the adaptive process.

9. G T~ Fechner.
Ueber em W,chtlges Psycho
phvslsches GrUlldgesllz zur Schatzung der Stern
grossen," Abhandlugen Saechsische Gesellschaft
der
Wissenschaften
Mathelllatische·Physische
Klasse 118581. 457.
lOA Koenig ann E Arodl1un
Exoe"mentelle Un~
tersuchungen uber die Psychophvslsche Fundamen·
talformel in Bezug auf den GeslchtslI1n. Sitzungs·
berichte Akademie der Wissenschaften 1889

641.
1 1 Selig Hecht, loc. cit.
~ 2 J F Schouten and L 5 Ornst81l
\leasuremems
on Direct and Indirect Adaptation by i\leans of BI
nocular ,\letI1OO.
Journal of the Optical Society
of America, XXIX \ 19391. 168-182

13. Howard DeHaven Baker. loc. cit.
14, S ~I AnSlis. . Visual Adaptation to Gradual
Change of IntenSity. Science CLV 119671. 7 10-11.
15. Judith W Onley and Charles E Sterheim,' Psychophysical Responses to Homochromatlc Stimuli of
Equal Brightness but Unequal Luminance '. Journal
of the Optical Society of America LVII: 2 1967.
25B-267.
16. A~ 'V~ G"iillhs and Joan Behrman
Dark Adaptation in Mongols,
Journal of Mental Deficiency
Research. XII1967 ,23-30.
17. Edward J Rinalducci.
PhotopIC Mechanisms of
Early Dark Adaptallon,' Journal of the Optical
Society of America. LVIII (1968). 690-696.
18. Ernst Simonson. "Adaplation to Glare," Ame' i·
can Journal of Ophthalmology, XLVI. No.3, PI. I
(1958). 354

1. Samuel Selden and Hunton D Sellman, Stage
Scenery and Stage Lighting New Yor~ F.S. CIOftS.
and Co., 19381, p. 222.

19. Note especiall; Psychological Index. 1895·
1925 and Psychological Abstracts 1925 to the
present.

2. Harry Helson, Adaptation-Level Theor; "e\·. York
Harper and Row, 1964 , p. 38

1O. P~ Ivloon and P E Spencer
The Speclfic3 Ion of
Foveal AdaPtation. Journal of the Optical Society
of America, XXXIII 1943 456.

3. G. ,'aid and A B. Clark, '\'Isual Adaptation and
Journal of General
the Chemistry of the Rods.
Physiology, XXII1937 . 102.
4. Howard DeHaven Baker.
The Course of Foveal
Light Adaptation
leasured by Threshold Intensity
Increment," Journal of
America. XXXIX (1949).
172
5. Selig Hecht, "Sensory Adapt3110n and the Slationar; State," Journal of General Physiology. VI
119321.355372.

21. BH Crawford. The Change of 'isual Sensltlv Y
with Time,
Proceedings of the Royal So~iety.
B. CXXIII (19371, 70.
22. Ransom Pickard.
A Study of the Centra, and
Peripheral Light and Dark Adaptallons with Varying
Backgrounds." British Journal of Ophthalmology.
XIX (1935}, 512.
23. Ibid., p. 481.
24. W.D Wright, ' Light AdaptatIon at the Fovea for
I\!ormal bes," British Journal of OPthalmology.
XXIII 19391 65.

Motion Picture Theatres (April 1966)

(The following report is a summary of an Industry Wage Survey prepared
by the U.S Department of Labor. and published as ItS Bulletin
o~ 1542
(April 1967). The complete document IS available from the U.S~ Government Printing Office (Washington D.C. 204021 for 35 cents. Editor!

Straight-time earnings of nonsupervisory employees in motion picture theatres averaged $1.59 an hour in April 1966.
Working an average of 22.5 hours, the 103,000 employees
covered by the survey had average weekly earnings of
$36. Average hourly earnings were $1.85 in the Northeast,

An-

Works cited

In 1935, after testing visual sensitivity,
Ransom Pickard suggested a number of prob
lems which still required further study. He
cites the size of the illuminated area; the
illumination, its kind and method of variation; the distance of the observer; the duration of adaptation; dayligh t threshold tests;
and standards of normality. 22 Since 1935,

Industry Wage Survey _

6. Judith \Vheeler Onley,
VlsuaISenSlti\'I[\
nual Review of Psychology, XV t 1964,.45

$1.83 in the West, $1.56 in the North Central region, and
$1.25 in the South. Men, accounting for three-fifths of the
work force, averaged $1.83 an hour compared with $ 1.16
for women.
Average hourly earnings were usually higher in conventional
theatres than in drive-in theatres and consistently higher in
metropolitan areas than in smaller communities. Among the
17 large metropol itan areas studied separately, average (mean)
hourly earnings ranged from $1.26 in Miami to $2.17 in
New York.

THEATRE DESIGN AND TECHNOLOGY

MAY, 1969

Table of Contents for the Digital Edition of Theatre Design & Technology - May 1969