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LIGHTING THE ACTING AREA

THE general acting area is that part of the stage floor
which may be used by the actor when he is in view of
the audience. For the purpose of lighting it, this area can
be assumed to be broken up into smaller sections, six for
the average stage, numbered as indicated in Figure 4.
These smaller areas are contiguous and of more or less
the same size and shape. The lighting of these areas
is primarily to give adequate and yet variable visibility to
the actor's face. The plane of illumination is, therefore,
generally considered at this level or about five and one
half feet above the stage floor (Figure 4).

INTENSITY
 The intensity of light illuminating an actor's face is
assumed to be adequate for the rest of his body. The
amount required for good visibility of the white man or
woman actor with the usual make-up varies chiefly ac-
cording to the amount of contrast between the bright-
ness of the face and the background. Where the back-
ground is dark, the illumination of the face can be
low. The most important reason for lighting the acting
area separately from the background lies in the fact
that the average scenery reflects light more brilliantly
than the actor's face.
 When the acting areas are lighted solely by border
                 33

34             LIGHTING THE ACTING AREA

strips and footlights, which give excessive general dis-
tribution of light, much more intensity of illumination
is required than is necessary with controlled, directed
light that is kept off the scenery. Therefore, it is possible
to create a greater effect of visibility with less illumina-
tion, when contrast is preserved, than under the old
system of using footlights and borders exclusively.
 The absolute range of illumination necessary for the
acting area is difficult to specify and equally difficult to
state simply. A normal range may lie between 5 and 50
foot-candles. The foot-candle is technically the amount
of illumination given to a surface one foot away from a
standard candle, or, roughly, the illumination per watt
given by an incandescent lamp. Where a lack of con-
trast exists, it may be necessary to use 100 to 250 foot-
candles, without exaggeration of the object. Since the
intensity of illumination varies inversely as the square
of the distance from the source, high-powered sources
must be used when the instrument is at a distance from
the acting area.
 Lens units (Figures 5, 6, 7 and 8), the instruments
used to light the acting area, have the ability to increase
the apparent candlepower of the beam of light from
a source in a useful direction even though they use
relatively little (3% to 25% at most)* of all light
created at the source.
*Step lens spotlights (Figures 5B and 9F) having a short focal
length lens use from two to four times the number of rays
emanating from the source.

LIGHTING THE ACTING AREA               35

 To obtain forty foot-candles of illumination at a
distance of twenty feet, an open light source as large as
the square of this distance (to offset the drop in intensity
due to distance), 20x20 x 40, or 16,000 candle power, must
be used. In case a standard spotlight is used the gather-
ing power of the lens itself is so effective that it can
condense the rays that would normally emanate from the
lamp within a 35-80 degree angle into a beam ranging
in spread from 7 to 45 degrees (Figure 9). By means of
measuring instruments it has been found that a lamp as
small as 750 watts, in a fresnel spotlight, can give a beam
powerful enough to supply 55 foot-candles at twenty
feet.*
 The table in the appendix lists a practical range of
intensities for fresnel and ellipsoidal spotlights.

  Plano-convex                    Maximum Candle Power
Watts       Lens                       Beam Spread
                         Spot     o    Med.    o   Flood    o
750.............. 5X 9   10,000   I5   2,000   30  1,000   60
400 ............. 5x 9   20,000   15   3,500   30  1,700   60
500 ............. 6x10   48,000   10   5,000   25  2,500   45
l000............. 6x10   90,000   10   11,000  25  4,500   45
1500............. 8x12  135,000   10   40,000  30 10,000   50
2000............. 8x12  195,000   10   55,000  30 14,000   50

 *The illumination in foot-candles (f.c.) at a point equals the
candle power divided by the square of the distance from the
instru-
                                 c. p.
ment to the point lighted, f.c.=-----
                                 dxd
 Example: How much illumination will be given at a distance
of 20 feet by a medium beam from a 750 Watt fresnel spot?
 From above, a 750 watt spot at medium spread (40 deg) has 22,000
candle power (c.p.). Square 20 feet and divide into 22,000.
12,000 / 400 = 55. Illumination will be equal to 55 f.c.



Figure 5: TYPES OF SPOTLIGHTS
An indication of the sizes of 3 different types:
(A) Plano-convex lens spots
(1) 8" lens           1000-2000 watts
(2) 6" lens            500-l000 watts
(3) 5" lens            250- 400 watts

(B) Fresnel or step-lens spots
(1) 14 or 16" lens 5000 watts
(2) 10 or 12" lens 2000 watts
(3) 8" lens 1000-2000 watts
(4) 6" lens 250- 750 Watts
(5) 3" lens 100 watts

(C) Ellipsoidal reflector spots
(I) 12"  lens 3000-5000 watts 10-12 deg beam
(2)  8"  lens 1000-2000 watts 20-24 deg beam
(3)  8"  lens   250- 750 watts 15-18 deg beam
(4)  6"  lens   250- 750 watts 26-34 deg beam
(S)  4 1/2" lens  250- 750 watts 40-45 deg beam

LIGHTING THE ACTING AREA 37

  These figures are only approximate and are calcu-
lated from the effects given by a certain group of lenses
-those normally used with each size of lamp. It is
apparent that the focus of the lamp or its position rela-
tive to the lens to give a certain spread of light has a
considerable influence upon the intensity of the light,
and therefore upon the distance at which it can be used
effectively (Figure 9). As the angle of spread increases
the intensity or effective distance decreases, very rapidly
at first and more slowly at the wide limit. In fact, the
range of distance for each beam spread within the limits
which will give from five to fifty footcandles is so great
that the table loses value unless every variable is con-
sidered. The 20 degree spread or medium focus is the beam
angle that is most useful in computing the wattage for
a certain throw or distance. Another interesting variable
lies in the fact that as the intensity decreases rapidly as



Figure 6: SPOTLIGHT SECTION

Section through a spotlight or lens hood, a typical construction
diagram of an average spotlight. The solid lines with arrows
indicate the typical direction of the rays of light. It will be
noted that rays which emanate from the rear of the filament are
reflected by a mirror so that they pass through the Center of the
filament toward the lens.

(1) Reflector adjustment.   (13) Color frame clamp or
    Thumb screw.                 spring.
(2) Spherical mirror.       (14) Base of the lamp.  
(3) Sharp focus position    (15) Socket, mounted in an    
    for the lamp in rela-        adjustable lamp car- 
    tion to the lens.            riage which can be
(4) The globular (G-             moved forward and
    type) glass bulb of          backward to provide
    the lamp. This type          focal range 
    is used exclusively in  (16) Focal slot.
    spotlights              (17) Focal handle, by which
(5) Concentrated high-           the position of the
    power filament burns         lamp in relation to the
    base down to hori-           lens is regulated.
    zontal.                 (18) Adjustment screw to
(6) Ventilating space.         raise and lower the
(8) Flood focus position         socket.    
    for the filament.       (19) Male pine connector.             
(9) Horizontal colorframe   (20) Asbestos leads
    slides or grooves.      (21) Bushing.
(10) Vent holes             (22) Access door, for re-
(11) Plano-convex lens.          moving and replacing
(12) A spring ring used to       the lamp and adjust-
     hold the lens in poi-      in the reflector.
     tin.

LIGHTING THE ACTING AREA 39

the spread is increased, so also the intensity decreases
when the distance is increased and the spread is kept
constant.
 The figures here cited are based upon the assumption
that the lamp is burning at full brightness, but for the
sake of balancing the lighting or intensities on the
various parts of the acting area, this is almost never the
actual case. The number of dimmers on the control
board should permit the dimming of each acting area
spot individually to obtain this balance. When dimming
an incandescent lamp, the intensity drops off quickly at
the start of the traverse of the dimmer handle and
slowly at the end. However, chiefly because the eye can
notice differences of intensity at the low more readily
than at the high end of the traverse of the dimmer, the
effect to the eye is that of even dimming. Some people
prefer to use one type of instrument with the same wait-
take lamp exclusively, instead of bothering to select per-
castile the wattage necessary. In this case, when high in-
tensity is desired the number of units is increased, and
where the opposite is desired the dimmer is used to



Figure 7: FRESNEL OR STEP-LENS SPOTLIGHT

Section through the spotlight showing structural features. The
solid lines with arrows indicate the typical direction of rays.
(1) Rear ventilator.     (9) Monoplane or biplane
(2) Spherical mirror.        concentrated filament
(3) Top vents.               source.
(4) Focal adjustment    (10) Socket mounting on
    range.                   adjustable worm gear.
(5) Fresnel lens.       (11) Focusing handle.
(6) Color frame holder. (12) Access door--this lid
(7) Spring ring to hold      raises to permit access
    lens in position.        to the lamp.
(8) Bulb of T-type lamp
    to burn base down to
    horizontal.


Figure 8: ELLIPSOIDAL REFLECTOR SPOTLIGHT

Section through spot showing the reflector and lens.
(I) Medium Per-focus Socket.
(2) Socket Holder permitting removal of cap, socket, and lamp for
    re-lamping.
(3) Push Shutter Handle.
(q) Medium Focal Length Plano-Convex Lens.
(5) Lens Adjustment Slide.
(6) Lens Drum extended to front position.
(7) Spring Ring Lens Holder.
(8) Color Frame Holders.
(9) Gate, generally about 3" in diameter.
(10) Yoke.
(11) Ellipsoidal reflector.
(12) Concentrated filament.
(13) Male Pin Connector.



Figure 9: SPOTLIGHT LENS CHARACTERISTICS

A diagrammatic indication of the manner in which lenses of dif-
ferent focal length (thickness) gather and converge the rays of
light emanating from a concentrated source and the angle of the
beam produced, due to the distance of the source from the lens.
In the left-hand column the light source is at the front or
"flood" focus, and in the right-hand column, the first two
figures indicate the light at rear or "spot" focus. Note that a
spherical reflector mounted at the rear of the source redirects
the rays through the source when the centre of curvature of the
reflector and the source coincide. In this way, the rays of light
emanating from the back of the filament are redirected through
the light source to the lens, and the amount of light in the beam
is thereby increased from 25% to 50%.
A. Front position, no lens, direct emanation, 90 degree beam.
B. Rear position, no lens, 45 degree beam.
C. Front position, medium thick lens, 45 degree beam.
Note: The number of rays in the 90 degree angle emanating
from the source are condensed into a 45 degree beam similar
to a rear position source with no lens. (See "B".) The greater
number of rays gathered by the lens gives correspondingly
greater intensity of light in the beam.
D. Rear position, medium thick lens.
The source is now at the focal point of the lens. Therefore,
the light rays, in the 45 degree angle emanating from the
source which is gathered by the lens emerge from the spot-
light parallel to each other and give what is known as an intense
"spot" Of light.
E. Front position, thick lens.
Here the rays emanating from the source in a 90 degree angle
are picked up by the lens and converged into a parallel beam,
correspondingly brighter than "D". However, in practice the
thick lens causes such irregularities in the beam and absorbs so
much light, due to its thickness, that its advantage is almost
completely offset.
F. Front position, Fresnel or step-lens.
This lens has the same gathering power as "E" because refrac-
tion is due primarily to the difference in angle between the
two faces of the lens. Note that the curved segments of the
step-lens follow precisely the curve of the thick lens indicated
here by a dotted line. The disadvantage of thickness is hereby
overcome so that the step-lens, when shaped to overcome irregu-
larities in the beam, is the most efficient type made. Further-
more, the length of the spotlight hood can be reduced. T type
lamp is necessary to obtain flood effect.

44 LIGHTING THE ACTING AREA

obtain the balance. Thus a 1000 watt spotlight can be
used to obtain the range, not only normal to itself, but
for any unit of lower wattage, or, two 1000 watt units
partially down on dimmer can serve the same purpose
as one 1500 watt spotlight. Nevertheless, the wisest
course to follow lies in the selection of the instrument
with the smallest wattage which will supply the range of
intensity desired in view of all the variables, and whose
maximum brightness when its dimmer is up full will
give all the illumination that is needed in any scene.
 The less regular variables that influence the inten-
sity of light given by a spotlight are introduced by ac-
cessories that are applied to the instrument to make it
more useful. A prefocus base lamp with a monoplane
filament has been developed to guarantee the position
of the filament in relation to the reflector and the lens
by using a bayonet type of socket similar to that used
in the automobile headlight lamp. In actual practice
reflectors can increase the average intensity of the beam
of light from 25 to 50 per cent, but this advantage is
generally offset by the danger of double image due to the
reflector's being off center (Figure 10). Reflectors can
be recommended only for spotlights more or less perma-
nently mounted or equipped with prefocus bases.
 Spotlights are seldom used without some kind of
color medium or diffuser. The total amount of inten-
sity transmitted by diffusers is relatively high--between
85% and 95%--but as they spread the beam, in part,
up to 180" the effective intensity in the useful direction
may be less than 50% Both glass and gelatin color

LIGHTING THE ACTING AREA 45

mediums affect intensity enormously. The degree of this
effect depends upon the purity of color from tints to hues
and the opacity due to the graying effect of mixed pig-
ments. The transmission of light is also dependent upon
the color of the medium, since the incandescent filament
is definitely richer in yellows and reds than it is in blue
and it becomes distinctly redder as it is taken down on
dimmer. The following is an approximate table of
transmissions of a few of the various color mediums:
Pink ...................... 65%   Medium Green ......... 18%
Magenta! .................. 25%   Dark Green* ..........  5%
Light Lavender ............ 27%   Straw ................ 85%
 (Surprise Pink)                  Light Amber .......... 80%
Dark Lavender ............. 15%   Medium Amber! ........ 60%
Light Steel Blue .......... 35%   Dark Amber ........... 48%
Dark Steel Blue ........... 20%   Light Scarlet ........ 65%
Light Blue ................ 20%   Light Red ............ 30%
Medium Blue ............... 10%   Medium Red ........... 15%
Dark Blue* ................  3%   Dark Red* ............ 10%
Blue-Green! ............... 10%
 * Used as Primary Colors
 ! Used as Secondary Colors

These figures can only be taken very generally because
no color mediums, even of the same lot, are exactly alike
in color content, and the eye reacts very differently to
different colors; it is more sensitive to the yellows and
the greens which always appear brighter than the blues
and reds.
 The use of mats, flippers, funnels and cutoffs of all
kinds (Figure 11), particularly when a diffusing medium
is used, tends to cut down the effective intensity of


    LIGHTING THE ACTING AREA 47

light from a spotlight. This is particularly marked when
the beam is at wide spread with the intensity relatively
low as a result, and an iris or a mat with a round hole is
used to cut down the spread of the beam.
 To sum up the variables involved in the selection of
the wattage for an acting area spotlight, each may be
considered in turn in respect to an illustrative problem.
  I. The position of the instrument is determined,
first, by the desired direction in which the beam of light
is to fall on the acting area, in order to give the actor's



Figure 10: REFLECTOR SECTIONS
Three typical concave curved sections used in stage lighting
instruments as a basis for controlling the rays of light. These
are all symmetrical sections which, when developed into a
three-dimensional form, have a circular face.
Number 1 in each case shows the position of the source at the
optical center and the direction of typical rays (at 10 degree
intervals, representing all the rays that emanate from the
source).
Number 2 indicates the effect when it is behind or inside the
optical center.
Number 3 indicates the effect when it is behind or inside the
optical center.
Number 4 indicates the effect when the source is above the
optical
center.
From these diagrams it is possible to trace the direction of
reflected rays under all conditions and they are useful in
analyzing the direction of reflected rays from various portions
of an enlarged light source--generally the case in practice.
 A. Spherical reflectors used in lens hoods or spotlights.
 B. Elliptical reflectors used in ellipsoidal reflector
spotlights and floodlights.
 C. Parabolic reflectors used in projectors and border lights.


Figure 11: CUTOFFS

LIGHTING THE ACTING AREA 49

face the best visibility and plastic quality, and second,
by the available structural arrangements which will
permit mounting the instrument to give as nearly as
possible this direction to the rays of light.
 2. The position establishes the distance and to some
extent the spread of light. It may be assumed that a 20'
throw and a 20 degree beam has been determined by the
ground plan of the setting and the size of the area to be
lighted. At this distance, with this spread, a 1000 watt
spotlight will give about 25 foot-candles of illumina-
tion.
3. The color medium with its diffuser transmits 50%
of the light rays so that the intensity of illumination is
cut down to 12 1/2 f.c. If the background is dark this will
give adequate visibility illumination; in fact, it may
produce a glare due to too much contrast.
 Experience will soon indicate the wattage necessary
for acting area spotlights, and the variables will be con-
sidered unconsciously in view of the numerous other
problems that are presented.

COLOR

 The color of the acting area lights must give the
actor's face a slightly exaggerated effect which is con-
sistent with his character and the motivation of the
lighting. It is no longer necessary to use make-up to
offset the unnatural direction, color and distribution of
strong footlights and borders. Make-up assists in de-
fining the character that the actor portrays, and lighting

50 LIGHTING THE ACTING AREA

should not destroy this effect, but since the color of the
light affects the appearance of pigment considerably it is
necessary to have the color of the make-up and the light
supplement each other. It is possible to select color me-
diums that give the made-up face a very complimentary
appearance; it is also possible to achieve the reverse.
 The color of the light is further determined by the
attempt to be consistent with the motivating light, such
as sunlight, moonlight, gaslight, etc. Motivating light
should more or less substantiate the amount of illumina-
tion necessary for the acting areas, and in turn, it is
wise to let the acting area illumination be of the color
and amount that would be given by natural sources. Thus
the color of the make-up may have to be adjusted to the
light used to co-ordinate with the motivating source.
This will be understood best by experimenting with
make-ups used under moonlight.
 The color of the acting area light also affects the ap-
pearance of costumes, but by balancing the acting area.
lights, or using the toning lights, costumes can be made
to appear as they were designed. A blue costume seen in
the yellow rays of the setting sun and the amber of the
acting area lights that go with it, will probably appear as
a lifeless gray unless acting area light: from another
direction, or the general toning light, has some blue in it
to pick up the color of the costume.
 When cross lighting is used on each acting area, to
provide plasticity and proper visibility to the actor's
face, those instruments focused in a direction which is

LIGHTING THE ACTING AREA 51

consistent with the motivating light will normally be of
the same color as the motivating light. This naturally
suggests the use of the complementary color from the
opposite direction. If warm color is used from one side,
cool color can be used from the other, just as the cool
blue of daylight appears in the shadows caused by the
warm rays from the sun.
 The effect of using a warm and cool color from oppo-
site sides on each acting area strikes at the root of another
make-up practice; that of using purple or blue lines or
shading to give the effect of wrinkles or hollows on the
face. The real problem of make-up is to provide certain
lines and shadows that make parts of the face reflect less
light than other parts, so that the reflecting character of
the make-up is important, and not its actual color. Since
purple and blue lines have the same reflecting value in a
cool-colored light as the ordinary flesh tints, black or
gray make-up should be used for wrinkles and hollows
and should be used with lighter base color for high
lighting.
 Ordinarily the face of the actor should appear normal.
It is obvious that except for spectacular effects the color
used in the acting area light should be just off white--a
warm or cool "tint", rather than a pure color. In general,
greens, blues and reds should be avoided and ambers,
pinks, and lavenders or steel blues used. These colors
will give the face tone and will not distort it. They will
also tend to promote visibility because objects can be
seen more clearly under tints than under pure colors.

52 LIGHTING THE ACTING AREA

The most practical advantage in their use lies in the
fact that tinted color mediums transmit more light than
the deep colors and thus make the acting area spotlights
more efficient. Deep colors, unless carefully selected, are
as apt to distort the appearance of a costume as to enhance
it, and in the same sense the tints tend to dilute the color
effect of a costume. When great richness of color is
desired in the acting area, obviously, some means of
lighting the face of the actor separately must be pro-
vided.

DISTRIBUTION

  The distribution of light over the acting area should
give what might be called dramatic visibility. Some
areas are obviously more important than others and
sometimes the best visibility from a dramatic point of
view is that which does not allow too clear a delineation
of form. The balance of intensity on the various areas
depends primarily upon the working out of the business
of the actor. The purpose of dividing the acting area
into small sections is to permit flexibility of visibility and
emphasis over the various parts of the stage. Occasion-
ally directors wish to suppress the arbitrary nature of
acting area spotlighting and are willing to confine the
action to areas lighted by only a few of the acting area
lights, or even to depend upon the motivating light
(provided it is adequate to give good visibility) during
the important scenes. This method requires the minimum
layout of equipment and it may be the goal toward

LIGHTING THE ACTING AREA 53

which the director and technician should strive, but
until directors are able to visualize the effect of lighting
while they are working out the business of a scene, it is
wiser to provide adequate visibility over the entire
acting area by the illumination from units that perform
this function alone. Spotlighting only certain pieces of
furniture and entrances and then relying upon the
brightness of the border lights to fill in the gaps, does
not provide enough flexibility, nor does it ordinarily
simplify the amount of equipment necessary.
 Visibility lighting is, at best, arbitrary and at odds
with a naturalistic effect so that every effort should
be made to make it as natural as possible. Light, directed
from the footlights, or even from the first border, is apt
to be bad. Beams of light from directly overhead cause
deep shadows on the face, and from the center front of
the balcony they tend to eliminate all form by allowing
no highlights and shadows, which are valuable contribu-
tions to our conception of the solidity of objects in
space (Figure 12).
 As long ago as the Renaissance it was discovered that
the best balance of light and shade to promote the effect
of plasticity could be obtained by considering sunlight
falling diagonally, from over one shoulder. Such diag-
onal lighting has been taken as a convention by archi-
tects in making renderings of their projects to show the
best indication of solid forms.
 Next to the delineation given by differences in bright-
ness, outline and color, the light and shade on an object


Figure 12: A CUBE UNDER DIFFERENT DIRECTIONS
AND DISTRIBUTIONS OF LIGHT
(1) General distribution, light coming from all directions,
thus practically eliminating the form of the cube.
(2) Direct down light such as might be given by a lens hood
mounted directly above the acting area. Very little illumina-
tion on the vertical faces.
(3) Center frontal lighting, as front the front of the balcony,
showing the position in which a shadow falls on the back wall,
directly behind the cube.
(4) Side lighting, at front the tormentor, showing the long
shadow, only fair top lighting, and giving sharp contrast be-
tween the two vertical faces of the cube.
(5) Center front at a 45 degree angle, showing equal illumina-
tion to she two faces of the cube and a less distracting shadow
than in diagram 3.
(6) Side lighting at 45 degrees, showing good top lighting
and illumination to one of the vertical faces, and a reasonable
position for the shadow.
(7) Back lighting. Showing good top lighting and separation
from the background by reason of contrast and therefore used
considerably in motion picture work, but giving poor illumina-
tion to the two vertical faces.
(8) Front lighting from below as from a footlight spot, show-
in the exaggerated effect of the shadow, no light on top, and
cool illumination of the two vertical faces.
(9) Diagonal lighting, giving a desirable balance of high-
light and shadow. This is the convention used by architects in
rendering their drawings.

LIGHTING THE ACTING AREA 55

give the dearest sense of plasticity; that is, the position
of objects in relation to each other and their solidity of
form. The sense of plasticity beyond the limits of stereo-
scopic vision (about fifty feet) is due primarily to the
direction and distribution of light. Plasticity is best
achieved when the direction of the light is at 45 degrees in
plan and elevation along a diagonal drawn between the
extreme corners of a cube (Figures 1, 2 and 3).
 Thus, if light is directed to the acting area as nearly
as possible along the diagonal of a cube the actor will be


58 LIGHTING THE ACTING AREA

projected from the center of each of the suggested act-
in areas on the stage toward the auditorium will strike
the walls and ceiling of the auditorium at the ideal
positions for mounting each of the acting area spotlights
(Figure 2). It will be found that the front areas of the
stage should be lighted from the ceiling, high up on the
side walls, or the face of the second balcony in the audi-
torium. Under some conditions the left hand spot on
the down-stage left area may be mounted close at hand
behind the left tormentor (Figure I). The same is true
on stage right, but proximity to the area lighted tends
to give an artificial effect. The face of the ordinary bal-
cony, even from the sides, generally provides too low
an angle. The up-stage, or three rear areas, can usually
be lighted from the stage side of the proscenium. The
general mounting locations should be numerous and
large enough to allow considerable latitude in the actual
placing of the instruments for the different scenes; they
should be accessible for changing color mediums and
focusing.
  Having determined the position for the instruments,
the distance to the area lighted is correspondingly fixed.
By referring to the tables of intensities (page 35) for
the wattage necessary within the range of throw, the
size of lamp and the instrument itself can be selected.
The six areas in the general acting space are determined
as much to meet the characteristic spread and intensity
of the spotlight as they are to promote flexibility. The
spread over one area is the widest angle that the ordinary

LIGHTING THE ACTING AREA 59

spotlight can give effectively. Thus, for small stages,
fewer areas can be used and for larger stages several
more, but as the number of units is increased the com-
plication of control is also increased, so that the six
divisions may be considered a happy medium.
 In this method of lighting, the illumination of the
areas should overlap sufficiently so that there are no
"dead pockets" through which the actor must walk. If
the business does not take the actor too close to the set-
ting, it is usually (but not always) possible to keep the
acting area lights from falling on the scenery. The
shadow of the actor moving against the scenery is bound
to be distracting. If, on the other hand, the beam of a
spotlight is allowed to fall on the scenery or even on the
floor of the stage, it gives a sharp oval pool of light
unless the edge is softened by the use of a diffusing
medium.
 By the use of either diffusers or step lenses the pools
of light are blended into the rest of the lighting and
the acting areas are pulled together. This practice, how-
ever, dissipates somewhat the control of the direction
of light so that it may fall on parts of the scenery and
auditorium which should not be lighted. The spill, or
stray light, caused by the diffusing medium can be
eliminated by the use of a funnel on the spotlight, but
the funnel must be unduly long if the spill is to be
entirely cut off.
 A practical method of soft edging a beam of a piano
convex spotlight is to scratch the edge of the color

60 LIGHTING THE ACTING AREA

medium, or to oil the center of a frost gelatin, so that the
normal transmission in the center of the beam is main-
tained.
 Great care must be taken to keep the light rays where
they are wanted. Since the acting areas are actuary
neither round nor elliptical, nor is the scenery con-
structed on curved lines so that it will fit the normal
shape of the beam from a spotlight, the form of the light
beam (the normal cone of light created by the lens)
must often be shaped by cutoffs, i.e., funnels, mats, flip-
pers, shutters, etc. (Figure II). On a brightly lighted
set this problem is not important, but cutoffs of some (
kind to shape the beam of light are often necessary i
accessories to the acting area spotlights.
 It is possible to obtain a sharp control over the form 
of light given by a spotlight only with the ellipsoidal
type (Figure 8). This unit provides maximum flexibil- 
ity, and more control than any other type of instrument
except the "effect machine" (stereopticon), or the Linne-
bach lantern (shadow projector), which produces per-
cise patterns.
 In practice ellipsoidal spots are invariably used as
"front" lights (in front of the proscenium) and generally
fresnels behind because of their natural soft edge.
  It is obvious that unless a great many instruments are
used the direction of each one is important. Some spot-
lights are equipped with sticky universal joints that per-
mit turning the instrument through a wide angle, and
holding it in whatever position it is set (Figure 13).

LIGHTING THE ACTING AREA 61

CONTROL
 Control of the light illuminating the acting area, as
for all other lighting, involves the control of intensity,
color, distribution, and changes. After each acting area.
spotlight has been focused and its beam directed to cover
the required area, it is possible to compose the stage
picture from the switchboard by varying the intensity
of each unit separately. This assumes that there is a sepa-
rate dimmer for each unit. If cool light comes from one
direction and warm from another, emphasis can be given
to either by the simple process of dimming from the
switchboard. When the proper balance of intensities has
been determined each dimmer will probably have a dif-
ferent reading because of the unequal distances of throw
and the differences of emphasis and color desired for
each area. Occasionally the acting area lights can be
grouped so that two or more are controlled by the same
dimmer, which should be of proper size or capacity to
handle the load. In this way the number of controls is
reduced, but flexibility of control is also limited.
 The building up of a definite lighting distribution, or
the balancing of intensities, is a little like modelling in
clay. Giving form to all the visual elements on the stage
is part of the procedure for a lighting rehearsal (ar-
ranged before the dress rehearsal), where everything
except the actor should be present.
 For most scenes, the acting area lights do not change
during the scene. The intensities at which the acting

    LIGHTING THE ACTING AREA 63

area lights are set are recorded on a set-up sheet which
is a record of the position of each switch and a reading
for each dimmer used in the scene. The set-up sheet is
not to be confused with the cue sheet which records
lighting changes (usually confined to motivating and
background lights) which occur during the scene.
  Movement is possible with lighting to a limited de-
gree. Abstractly, changes of light can be perceived more
readily than changes in sound, but our knowledge of
instruments and light, and our light sense, are not yet
developed to the point of establishing lighting as an art
form in the same terms as music.


Figure 13: TYPES OF MOUNTINGS
Planes of rotation indicated by arrows. Lens instruments
illustrated in A to E are generally mounted with a universal
joint--two planes of rotation perpendicular to each other so that
they can be focused in a variety of directions.
Generally the joints should be tight and sticky, so that the
instrument can be redirected and will retain its new position.
]oints are made tight by the use of leather or spring washers.
Generally the joint should be tightened by a wing nut or thumb
bolt, although in a number of cases a set screw or a nut is
provided to insure a permanent mounting.
 A. Horizontal pipe mountings.
 B and C are stand and bore mountings, generally used on the
 floor. In this respect they are portable unless, for the sake of
 security, they are screwed to the floor or the surface on which
they are mounted.
D and E. Vertical pipe batten mountings, such as might be
found on the tormentor.

64 LIGHTING THE ACTING AREA

 Eventually each change in situation during a scene
may be enhanced by changes in lighting. Most attempts
to do this now with the average type of switchboard
require endless rehearsal and in the end are apt to be
distracting. But slow, subtle changes as in a sunset and
sunrise can be simulated on the stage if great care is taken.
The distribution of light at any moment in a change
should be considered in terms of a static effect, recordable
as a definite group of dimmer readings. This is all the ;
more important in view of the fact that the switchboard
operator is not always able to see the effects which he is 
creating for an audience. Most switchboards with a suf- 
ficient number of dimmers are adequate pieces of appa- 
ratus to provide a static set-up, but the problem of mak-
ing proportional time changes on them implies per-
setting dimmer readings and fading from one set-up to
another.
 With a striplight having two or more color circuits it
is possible to create a change of color by dimming the 
intensity of one or all of the circuits up or down, but
with a spotlight (a single source unit) the range of color
control is definitely limited. Of course, it is possible to 
change color mediums between scenes, if the instrument
is accessible. The Europeans employ a method of chang-
ing color mediums mechanically by pulling the color
medium across the face of the instrument with a wire
cable operated over a series of pulleys from the switch- 
board. Our own manufacturers have developed an elec-

LIGHTING THE ACTING AREA 65

tro-magnetic color control for pulling the color medium
over the face of the instrument or allowing it to drop
clear of the beam. With neither of these methods is the
change subtle. The spotlight has not yet been developed
which will give as good a range of color control as can
now be had with a striplight. Double or triple sets of
instruments are sometimes installed to give a color range
desired.
 As a rule, only floor units are changed in position from
scene to scene. Hanging units can be taken up or down.
If accessible, the direction and even the shape of the
beam of the spotlight can be changed by hand for each
new scene. The best example of control over the distri-
bution of light is the hand-operated, high-powered arc
follow spotlight often found in the projection booth. But
these instruments are not particularly useful in legiti-
mate plays because they are not under control from the
switchboard operator. Some attempts have been made to
control the direction and spread of spotlights by means
of remotely controlled motors, but the apparatus is too
expensive for ordinary use. For the present, changes of
distribution from the acting area spotlights during a
scene are limited to a variation of the intensity or to
hand operation at the instrument.
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