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THE PHYSECAL 9RiNCiPLES AND
PROPERTIES OF LEGHTING DESIGN
FOR ENTERMRS: A COMPILATSON FROM
A SURVEY OF UTERATURE

Thesis for the Degree at M. A.

MECHEGAN SMTE QMVERSETY

KATHLEEN PARRISH FETERSGN
1970

LIBRARY
Michigan State
University

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Michigan State University

HUMAN ENVIRONMENT 8. DESIGN
CoIIe-ge of Human Ecology

East Lansing, Michigan 48823

THE PHYSICAL PRINCIPLES AND PROPERTIES OF
LIGHTING DESIGN FOR INTERIORS: A
COMPILATION FROM A SURVEY OF

LITERATURE

BY

Kathleen Parrish Peterson

A SPECIAL PROBLEM

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF ARTS

Department of Textiles, Clothing and Related Arts

1970

ACKNOWLEDGMENTS

My thanks goes to the people of the Large Lamp
Institute of General Electric Company, Nela Park, Cleveland,
Ohio, and to the Illuminating Engineering Society for
supplying much of the needed information for this study.

My gratitude also goes to my special problem committee,

Dr. Gertrude Nygren and Dr. Robert Rice of the College of
Home Economics, and Miss Alberta Dobry of the College of
Education, Michigan State University, for all their help
and guidance. I esPecially want to acknowledge my grate-
fulness to Dr. Mary Shipley, my special problem advisor,
for her patience and unwavering trust in me. I am also
grateful to my wonderful husband whose faith and encourage-

ment led me to the completion of this program.

ii

TABLE OF CONTENTS

INTRODUCTION . . . . . . . . . . . . .
An Historical Sketch of Lighting . . .

The Need for the Study of Lighting
Interiors . . . . . . . . . .

Chapter

I. GENERAL PROBLEMS, PRINCIPLES, AND OBJECTIVES

OF LIGHTING O I O O O O O O O O 0

Definitions of General Lighting Terms. .
The General Problem. . . . . . . .
The Principles of Good Lighting. . . .
The Environmental Objectives of Residence

Lighting. . . . . . . . . . .

II. LIGHT CONTROL . . . . . . . . . .

PART ONE: PRINCIPLES OF LIGHT CONTROL,
LIGHTING METHODS, AND MODES
OF DISTRIBUTION

The Physical Principles of Light . . .
Lighting Methods. . . . . . . . .

PART TWO: DESCRIPTIONS, FUNCTIONS, AND
MATERIALS USED IN LIGHT CONTROL

Materials Used in Light Control. . . .
Finishes Used in Luminaires . . . . .

III. TYPES OF LIGHT: QUANTITY AND QUALITY . .
Natural Light. . . . . . . . . .
Artificial Light. . . . . . . . .

Quantity of Light . . . . . . . .
Quality of Light. . . . . . . . .

iii

l3

l8

18
28

31
32

33

33
37
46
55

Chapter

IV. STRUCTURAL, PORTABLE, AND ACCESSORY
LIGHTING . . . . . . . . . . . .

Structural Lighting. . . . . . . .
Portable Lighting . . . . . . . .
Accessory Lighting . . . . . . . .

V. NEW DIRECTIONS IN LIGHTING AND THE FUTURE OF
LIGHTING IN INTERIORS. . . . . . . .

Contemporary Lighting Today . . . . .
New Innovations in Lighting . . . . .
The Future of Lighting for Interior
Designers . . . . . . . . . .
BIBLIOGRA-PHY O O O O O O O O O O O I C
APPENDICES
Appendix
A. Basic Modes of Lighting . . . . . . .
B. Incandescent Lamp Shapes. . . . . . .
C. Shapes of Fluorescent Tubes. . . . . .
D. Structural Lighting Types . . . . . .

E. Portable Lighting Measurements and Placement

F. Contemporary Portable and Accessory Lighting

iv

59
59
66
71
75

75
76

76

78

82

84

85

86

9O

95

LIST OF TABLES

Table Page
1. Reflectances and Approximate Munsell Values

for Interior Surfaces of Residences . . . 57

2. Lumen Counter Method. . . . . . . . . 58

Figure

l.

10.
ll.
12.
13.
14.
15.
16.

17.

LIST OF

The Law of Reflection
Specular Reflections
Specular Reflections
Spread Reflection .
Diffuse Reflection .
Compound--Diffuse and

Compound-~Diffuse and

Specular

FIGURES

Spread.

Compound--Specular and Spread

Parabolic Reflector.
Elliptical Reflector
Circular or Spherical
Refraction. . . .
Refraction. . . .
Direct Transmission.
Spread Transmission.

Diffuse Transmission

Reflector.

Diagrams of Light Measurement

vi

Page
l9
l9
19
21
21
22
22
22
23
23
23
25
25
26
26
26

48

INTRODUCTION

An Historical Sketch of Lighting

The electric filament lamp, invented by Edison in
1879, revolutionized man's way of life. Prior to his dis-
covery, man was forced to light his environment by natural
sources of light or by kerosene and oil lamps. In 1910,
Dr. William Coolidge improved upon Edison's carbon filament
lamp and produced the tungsten filament lamp, still in use
today with only minor modifications. In 1931, Langmuir
discovered that by filling the tungsten lamp with inert
gas, he could double the efficiency of the incandescent
lamp. Other modifications, such as inside frosting and
coiled filaments, further improved the incandescent lamp
(General Electric, Incandescent Lamps, 1962, p. 3). In
1938, the fluorescent lamp came into being, and since that
time has undergone significant advances (General Electric,
Fluorescent Lamps, 1965, p. 3).

The Need for the Study of
Lighting Interiors

Lighting for contract and residential design has

been sadly neglected by interior designers in the past. It

has been the experience of this investigator in practice,

as well as in discussion with other practicing interior
designers and educators, that there is a definite and
urgent need for the study of lighting design.

In order to fulfill this need, a compilation such as
the one described herein, can serve as a guide for future
course planning or as a basis for a course syllabus. It
is the purpose of this paper to create for the student
and/or instructor of Interior Design, a compilation of
known requirements concerning the physical principles and

properties of lighting design for interiors.

CHAPTER I

GENERAL PROBLEMS, PRINCIPLES, AND

OBJECTIVES OF LIGHTING

Definitions of General Lighting Terms

In order to gain an understanding of specific

lighting concepts, it is necessary at this point, to define

certain lighting terms. These terms are divided into three

groups: (1) the measurement of light, (2) visual terms,

and (3) lighting equipment.

1.

The measurement of light.--

Candela:

Lumen :

"the unit of luminous intensity of a
light source in a specified direction.

"a unit for the light-producing power
of a light source . . . the rate at
which light falls on a one square foot
area surface which is equally distant
one-foot from a source whose intensity
is one candela.

Footcandle: "Density of light striking each

 

and every point on a segment of the
inside surface of an imaginary one-
foot radius sphere with a l-candle-
power source at the center" (General
Electric, Light; Measurement and Con-
trol, p. 5).

Footlambert: the quantitative unit for measur-

 

ing the brightness of a surface; "If
a surface held one-foot from a candle
appears perfectly white and diffuse,
its brightness is one footlambert"
(Interiors, 1950, p. 118).

3

Brightness: the degree of apparent lightness
on a surface.

 

Visual terms.--Kaufman (1966, p. 3-7) defines
visual terms in the following ways:

Visual field: "the locus of objects or points
in space which can be perceived
when the head and eyes are kept
fixed.

 

Visual task: "those details and objects which
must be seen for the performance
of a given activity, including the
immediate background of the details
or objects.

 

Visual surround: "all the portions of the
visual field except the visual
task.

Glare: "the sensation produced by bright-

nesses within the visual field

that are sufficiently greater than
the luminance to which the eyes are
adapted to cause annoyance, dis-
comfort, or loss in visual per-
formance and visibility."

Lighting equipment.--

Luminaire: a total lighting unit which in-
cludes the source of artificial
light and the fixture housing the
source.

Lamp: "a generic term for a man-made
source of light . . . (a lighting
unit consisting of a lamp with
shade, reflector, enclosing globe,
housing or other accessories is
also called a 'lamp.‘ In such
cases, in order to distinguish be-
tween the assembled unit and the
light source within it, the latter
is often called a 'bulb' or 'tube'
if it is electrically powered.)"
(Ibid.).

Bulb: a layman's term for lamp; also the
varied glass, shaped enclosure of
a lamp which keeps air out and
filling gas in.

The General Problem

 

I. Considerations Pertinent to the
Analysis and SolutiOn of'Most
Igterior Lighting Design

ProbIems

 

 

Light, the subject of this paper, obviously is a
necessity if we are to see the world around us. Without
some kind of light we could not see form, line, color, or
texture. The ways in which light are used by the interior
designer, architect, or lighting designer, determine whether
or not our visual, aesthetic, emotional, and spatial needs
are met. In the past, light, especially daylight, was used
"to give form to planes, curved surfaces, and structural
design" (Ibig., p. 10-2). At the start of the twentieth
century, attempts to use artificial light as a structural
element were begun (Kohler and Luckhardt, 1959, p. 117).
Today, on a much broader basis, artificial light is used
for the same purposes. The availability of the many differ-
ent types of light sources, luminaires, light control de—
.vices, and lighting equipment has made it possible to use
an almost unlimited range of lighting treatments to create
a desired effect. In all aspects, the art of lighting is
influenced by the individual interpretation of the interior
designer, the architect, and the lighting designer (Kauf-

man, p. 10-2).

A. Function of the structure.--The application of
lighting is greatly influenced by the function of the
structure. The application techniques designated for com-
mercial or industrial lighting have developed around light-
ing solutions for the differing types of visual tasks
generally encountered in each type of building. Each
technique is a combination of engineering theory, applied
experience, and acceptance on the part of the consumer of
the type of application for a particular field. Kaufman
(p. 10-2) states:

. . . Because these include more than an objective
assessment of engineering considerations, it is neces-
sary to relate the design of a lighting installation
to the particular occupancy of the space it is to
serve.

Commercial and residential applications differ
in that:

The near-uniformity of light distribution employed
in schools and offices is usually incompatible with
the intent of most residential interiors. . . . The
tastes and varying eyesight demands of the individual
family necessitate various lighting effects (IES
Committee on Residence Lighting, 1953, p. 133).

Commercial or industrial lighting further differs
from residential lighting in that " . . . In the home . . .
light is used chiefly to create a mood--not to the ex-
clusion of other considerations, but predominately" (Kohler
and Luckhardt, p. 133). The visual task, however, is con-

sidered of primary importance in a building, regardless of

the function of the building.

B. Lighting systems.--Illuminating engineers have
classified lighting systems as: (l) "the general type of
lighting produced," and (2) "the general layout of lumi-
naires" (Kaufman, p. 10-2). The Illuminating Engineering
Society (IES) has grouped generically the general type of

light produced as: (1) general, (2) local, (3) localized

general, and (4) supplementary.1

C. Luminaires.--Luminaires have been classified

 

on the basis of light distribution. They are direct, semi-

direct, general diffuse, semi-indirect, and indirect

(Ibid.).

D. The selection of light sources.--The selection
of light sources, their luminaire characteristics, and the
layout system "are closely interrelated in an application
technique" (Ibig.). Local conditions, such as temperature,
dust and dirt, or color will greatly influence the selection
of the light source, how it is applied, operated, and its
<3utput and maintenance.2 Economics becomes the deciding

:Eactor where various light sources are equally applicable

(Ibid.).

E. The initial and operating costs.--The initial
61nd operating costs are of primary concern in any lighting

Esystem design. The costs must be balanced against the

¥

1See Chapter II. 2See Chapter IV.

results, and the designer must rely upon his personal
experience and the experience of others in the solution of
comparable problems if there is any such experience avail-
able (Ibid., p. 10-3). Kohler and Luckhardt (p. 133).
feel that " . . . All good lighting must provide for the
needs of vision, satisfy hygenic requirements, meet aes-
thetic standards, and achieve a good spatial impression
and do all this economically."
II. General Statements Concernigg
Interior Lighting Design Problems
The eye, like the rest of the body, dislikes strain
and welcomes ease. Comfortable lighting makes it easy
to see what you are doing and where you are going. It
brings out all the beauty in the rooms you live in--
shows up the subtlest colors, the textures, the forms,

so that you can enjoy them at any hour (House and
Garden, 1967, pp. 110-11).

 

To the interior designer, lighting may be con-
sidered an art. To the illuminating engineer, lighting is
considered a science. In reality, it is both of these, and
(both concepts must be employed in the design of lighting
Systems if the system is to meet the needs of those for

Vihom.it is being designed. Kaufman (p. lO-l) supports
this idea with his statement:

The art and science of modern interior lighting
design is broader in scope than it is often thought
to be. In general, it involves several factors:
light and vision, the visual response of the eye under
varying light and environmental conditions. Others
relate to the production, control, and distribution
of electric light. And still others relate to the
enclosure itself, or building structure, including
size, shape, color, and related decorative consider-
ations. .

Whiton, in Elements of Interior Design and Decor-
ation (1965), states the general problem to be one of
practical and aesthetic considerations, although he natur-
ally emphasizes the aesthetic more than does Kaufman when
Whiton (p. 679) states:

. . . The planning of artificial lighting presents a
problem that requires both practical and esthetic
considerations. The average room needs light for
general illumination and special lights for particular
areas or activities. The lighting equipment and fix-
tures must be consistent with the style of decorations,
must contribute to the desired character and atmosphere,
and must be adequate for the purpose of the room.

The psychological and physiological implications of
lighting must not be neglected.1 Kohler and Luckhardt

(p. 117) state:

. . . Just as every artist must learn to handle the
tools of his craft correctly, so he who would build in
light, would use light superlatively as a building
block, must know the virtues of light, the physio-
logical and psychological effects connected with light
in order to master them.

This writer firmly believes that the interior de-
signer should and must strike a balance between being able
tn: apply the science of lighting and the art of lighting.
Because progress is being made so rapidly in the lighting
iiield, it is the responsibility of the interior design stu-
<3ssnt_as well as the practicing interior designer to keep

Eilareast of the new developments and apply this knowledge in

‘tJne best ways possible. Kaufman (p. 10-2) supports this

 

 

lSee paper by Judith Orr, Michigan State University,
31969, for the psychological and emotional effects of
lighting.

10

with his statement that designers must have " . . . a
competent knowledge of the principles of light control and
of the lighting tools and devices which are available for

the problem involved."

The Principles of Good Lighting

I. The Aims of Good Lighting

The Illuminating Engineering Society (IES Code,
1961, p. 1) states three aims of good lighting. They are:
(l) to "promote work and other activities carried on," (2)
to "create, in conjunction with the structure, a pleasing
environment conducive to interest and a sense of well-
being," and (3) to "promote the safety of the people using
the building."

To support the IES aim of safety, the Committee on
Residence Lighting (p. 7) has elucidated on this point for
residential use. They believe that all lighting and the
switches that control the lighting, must be strategically
placed in order to insure positive and rapid seeing from
one room to another. This is particularly true at danger
ltncations such as stairs, medicine cabinets, and equipment
wit:h moving parts--from kitchen appliances to electric

rélzors. The Committee also suggests for convenience, as
well as safety, the use of low-wattage night lights in

'bailfxrooms, bedrooms, halls, and at the top of stairs.

 

11

II. The Realization of the
Aims of Good Lighting

 

 

Equally applicable to commercial or industrial
lighting and to home lighting, these aims must be realized

in a variety of ways spelled out below (IES Code, p. l).

A. Planning brightness and colorgpatterns.--Care-
ful planning of the brightness and color patterns1 in the
work or task area and the surrounding area is essential be-
cause attention must be drawn naturally to the important
areas, detail must be seen quickly and accurately, and the

room should be free from gloom and monotony.

B. Directional lighting.-~Directional lighting
should be used where it is appropriate to assist in seeing
detail and to give good modeling of objects, such as art

objects, paintings, etc.

C. Glare.--G1are, reflected or direct, must be

 

controlled in order to eliminate any visual discomfort.

The degree of glare from a direct View of a light source
depends on the brightness and area of the source, its
LNDsition, and the average brightness of the room back-
grwaund. Reflected glare is caused by polished or glossy
Salffaces and can be reduced by rearranging the position of

the light source out of the angle of vision, by reducing

1See Chapter III.

 

12

surface brightness of the source, and by increasing the

lightness of the immediate background to the task (Ibid.,

p. 6).

D. Flicker.--Flicker results when discharge lamps

 

operate on alternating current and their light output

varies in each cycle. One will find this annoying flicker
often in tubular fluorescent lamps. It may be overcome by
fitting opaque shields over the lampends, or by screening

the ends from direct view (Ibid., p. 7).

E. Correlating lighting throughout an area.--
Correlating lighting throughout an area is necessary in
order to prevent excessive brightness differences between

adjacent areas as well as for safety precautions.

F. Installing emergency lighting systems.--
Installing emergency lighting systems is a preventative
measure against injury in case of a power failure to the

regular lighting system.

G. Maintaining lighting installations.--Maintain-
ing'lighting installations is all-important to a lighting
sYstem to increase the life of the lamp and increase the
Efficiency level of the lamp. The IRS (Ibid., p. 10)

fEi‘els that:
. . . Unless both the structure of a building and the
lighting equipment are well maintained, the aims of
egood lighting will in time be defeated; the lighting,

Iaatural or artificial, will no longer fulfill its pur-
I?ose adequately, the cost of providing useful light

 

13

will increase, and the appearance of the building will
deteriorate. . . . Films of dust and dirt deposit on
all room surfaces and the consequent depreciation in
reflection factors affects the level of illumination in
the room.

Unless the luminaire and the room surfaces are main—
tained, both factors will increase lamp inefficiency and
decrease the life of an expensive and necessary item in the
home. Luminaires of all types, also, are a natural attrac-
tion to bugs, dust, and dirt. If the luminaires are not

cleaned regularly, the output efficiency of the luminaire

is reduced greatly.

H. Lighting output efficiency.--Lighting output
efficiency "of artificial lighting equipment decreases
progressively with time from three causesz" (lgig., p. 11)

l. A gradual fall in light output of the lamps.

2. A decrease in the efficiency of fittings

caused by dust or other deposits on reflecting
or transmitting surfaces.

3. The permanent discoloration of reflecting or

transmitting surfaces caused by corrosion
(apparent in some atmospheres), by age, or by
radiation (Ibid., p. 28).
The Environmental Objectives of
Residence Lighting
Unlike some commercial or industrial lighting
S.YStems, residence lighting has no set systems of lighting

fcxr- Inost areas. Any visual task performed by an individual

 

 

14

may take place in any room. Therefore, lighting of the
individual task areas is usually considered first by the
designer. These areas are then tied together with some
form of general or environmental lighting system. "This
'tying-together' process is important in achieving a com-
fortable visual environment" (Kaufman, p. 15-1). As
stated earlier in the chapter, there are four things that
must be considered in supplying a pleasing lighting en-
vironment, and those things for which all good lighting
must provide. They are:

l. Supplying the needs of vision. In supplying
the needs of vision, the designer must con-
sider the "seeing zones" (1219') and luminance
ratios in these zones. The three "seeing
zones" are:

a. Zone l--the task itself, which demands
local lighting.

b. Zone 2--the area immediately surrounding
the task.

c. Zone 3--the general surroundings.

Kaufman (p. lS-l) states:

In the immediate surround . . . , luminances that
are noticeably greater than the task luminance or which
are less than l/lO the task luminance contribute to
visual discomfort and are apt to be distracting. The
luminance of substantial areas in the general surround
should not exceed ten times the task luminance or be
Inuch less than 1/10 as bright. . . . These luminance

:relationships become more important as illumination
.levels increase and as duration of tasks is lengthened.

15

The IES takes this approach to luminance ratios
(Ibido I p. 10-1):

The general approach to low luminance ratios over
an entire visual field is to limit the luminance of the
luminaires and fenestration, and to build up the lumi-
nance of all other interior surfaces (ceiling, walls,
trim, floor, work surfaces, and equipment) by suitable
reflectances, textures, and distribution of light.

The balance of illumination in the
visual field can be accomplished by reducing
high luminances at window areas and luminaires
by shielding and by low-transmission shading
materials; by balancing large areas of room
surfaces using favorable finishes;1 and by
providing additional lighting in the visual
surround (Ibid., p. 15-1).

2. Supply a hygenic lighting system. Research has
indicated that adverse effects may result from
less than optimum lighting. The National
Technical Conference of the IRS reported in
1966 (p. 6) that:

. . . Long exposure to less than optimum lighting con-
ditions can affect the health and accelerate the aging
process of people, and day by day can unfavorably
affect their attitude to their work and their physio-
logical efficiency.

In relation to daylight factors and

hygiene, Kohler and Luckhardt (p. 129) stress

the importance that German school doctors,

V’ 1See Table l, "Reflectances and Approximate Munsell
aJ-lles for Interior Surfaces of Residences."

 

16

hygienists, and governmental agencies placed

on lighting in school rooms. They state:
. . . school doctors early questioned whether the
lighting in school rooms by day was adequate for read-
ing and writing. Soon thereafter, hygienists began
studying what supply of light should be provided in
living quarters, and certain government agencies also
turned their attention to these problems and sought to
solve them by regulation.

Kohler and Luckhardt (p. 130) also go
on to discuss the legislative provisions that
were made over 160 years ago by Prussian pro-
vincial common law demanding that the tenant,
"if he steps to a closed window in the lowest
story, may see the sky." This was inspired by
the sense that "it is one of the rights of man
to have the space in which he dwells arranged
so that he can feel well and keep well; it is
a rule of hygiene" (Ibig.).

Unfortunately this code was dropped in
modern times when air conditioning and artifi-
cial light began to influence people so that
their need to see and move to daylight was no
longer necessary. Kohler and Luckhardt, how-
ever, point out that we have conveniently
forgotten about the un-air-conditioned tene-
ments of most cities with their sad and un-

hygienic surroundings, and feel that such a

requirement as the Prussians made so many years

17

ago is still very appropriate and needed in our
own day.

Meeting aesthetic standards. Meeting aesthetic

 

standards should not be neglected by the de-
signer of the lighting system. By virtue of
their education, experience in dealing with
aesthetics, and natural love of beauty, in-
terior designers should be the most aware of
these standards of lighting and seek to attain
them at all times.1

Achieving good spatial relationships. Well-

 

planned, designed lighting systems can achieve

good spatial relationships within a specified

2
area.

 

1

See Chapter IV, also, for discussion of aesthetic

design factors in structural, portable, and accessory

lighting.

2See Chapter III, quality and quantity of light.

CHAPTER II
LIGHT CONTROL

PART ONE: PRINCIPLES OF LIGHT CONTROL,
LIGHTING METHODS, AND MODES
' OF DISTRIBUTION
The Physical Principles of Light
Light, which is that portion of radiant energy

which reacts upon the eye to produce the sense of sight,
may be controlled in the following ways: (1) reflection,
(2) refraction, (3) transmission, (4) polarization, (5)
diffusion, and (6) absorption. These physical principles

of light control will be discussed in detail.

I. Reflection

Kaufman (p. 6-1) defines reflection as "the process
by which a part of the light falling on a medium leaves
that medium from the incident side." Reflection is divided
into four types: (1) specular, (2) spread, (3) diffuse,
and (4) compound. We shall look at each type of reflection

separately (see Figure 1, page 19).

A. Specular reflection.--The surface is of a

polished medium, as in polished or electroplated metals

18

 

l9

 

Figure l.--The Law of Reflection

 

 

 

 

Front
Silvered
I
I
I
\ ,
I
Polished /
Surface j
‘r j
r,

7

jm~
0
H
m
m
m
‘V\HU\

Figures 2 and 3.--Specular Reflections

20

(copper or gold), silvered glass, or plastic mirrors (see

Figures 2 and 3, page 19).

B. Spread reflection.--The surface is figured in

 

some way such as corrugated, deeply etched, or hammered.
Any rays that are reflected from such surfaces are spread.
Depolished metals, brushed or pebbled surfaces "consist of
small specular surfaces in irregular planes" (Ibig., p.

6-2)(see Figure 4, page 21).

C. Diffuse reflection.--The surfaces are rough or

 

"composed of minute crystals of pigment particles" (2229'!
p. 6-2). Flat paints and other matte surfaces or finishes
exhibit very little light direction control. These sur-
faces are used when a wide distribution of light is desired

(see Figure 5, page 21).

D. Compound reflection.--Many compound materials,

 

such as embossed aluminum or semi-gloss paint, exhibit a
combination of specular, spread, and diffuse reflections

(see Figures 6, 7, and 8, page 22).

E. Basic reflector contours.--There are three
common reflector contours which control the light being
emitted at the source. They are: (l) parabolic, (2)
elliptical, and (3) circular or spherical (see Figures 9,

10, and 11, page 23).

21

¢M

Figure 4.--Spread Reflection

 

 

Figure 5.--Diffuse Reflection

22

 

 

Figure 6.--Compound--Diffuse and Specular

 

 

Figure 7.--Compound-- Figure 8.--Compound--
Diffuse and Spread Specular and Spread

23

 

 

Figure 9.--Parabolic Reflector

 

Figure lO.--Elliptical Figure ll.--Circular or
Reflector Spherical Reflector

24

II. Refraction
Kaufman explains refraction in this manner:
A change in the velocity of light occurs when a ray
leaves one material and enters another of greater or
less optical density. . . . Except when light enters
at an angle normal [perpendicular] to the surface of
a medium of different density, the change in speed
always is accompanied by a bending of the light from
its original path at the point of entrance (Ibid.,
p. 6-2). (See Figures 12 and 13.)
This kind of phenomenon is apparent when we view
at an angle a straw or pencil in a glass of water, and the
object appears to bend at the surface of the water. Prisms

and lenses, either convex or concave lenses, are used as

refractors as well.

III. Transmission

 

Materials used in the transmission of light may be
glass, plastics, textiles, crystals, etc. Transmission is
achieved in four ways: (1) direct, (2) spread, (3) dif-

fuse, and (4) mixed.

A. Direct transmission.--The direction and charac-

 

teristics of the light beam sent through clear glass or
plastics are not changed appreciably (see Figure 14, page

26).

B. Spread transmission.--Spread transmission

 

occurs when a beam of light is sent through a lightly dif-
fusing medium, such as frosted glass. Spread transmission

is used for brightness control, where sparkle and brillance

25

Normal
Angle

Figure 12.--Refraction

Figure 13.--Refraction

2

Transmitti

II

6

ng Medium

(2)

 

 

7 Light Source

Figure l4.--Direct Transmission

Transmitting Medium

4 /
IM Light Source

6

 

 

Figure 15.--Spread
Transmission

Transmitting Medium

414

 

/
Light Source

&

 

 

Figure 16.

--Diffuse

Transmission

27

is desired, and in enclosed globes of moderate uniform

brightness (see Figure 15, page 26).

C. Diffuse transmission.--Diffuse transmission

 

occurs when light is sent through a dense medium. Light
is then scattered in all directions. Examples of these
mediums would be white, opal, and prismatic glassware
(General Electric, Light Measurement and Control, pp. 21-

22)(see Figure 16, page 26).

D. Mixed transmission.--Mixed transmission permits
regular transmission of certain colors while it diffuses

others. Opal glass is an example (Kaufman, pp. 6-8, 6-9).

IV. Polarization

Polarization, a relatively new discovery, is ex-
plained by the General Electric Company in the following
statement:

Ordinarily, light rays are considered to vibrate in

all directions perpendicular to the direction of travel
of the light. Light rays can be modified by polari-
zation so that the vibrations are predominately in one
plane. This polarization of the direction of vibration
can be caused by a variety of transmitting or reflect-
ing media. The sky, water surfaces and certain cry-
stals such as tourmaline are examples of polarizing
media in nature. Special polarizing plastic materials,
transparent materials which have been internally
stressed, and multi-layers of glass or plastic are
examples of man-made polarizing materials (General
Electric, Light Measurement and Control, p. 26).

28

V. Diffusion
Diffusion may be defined as "the breaking up of a
beam of light and the spreading of its rays in many

directions" (Kaufman, p. 3-9).

VI. Absorption
Absorption "occurs when a light beam passes through

a transparent or translucent medium or meets a dense body.
. . . Practically all colored objects owe their color to
selective absorption in some part of the visible spectrum"
(Ibid., p. 3-9). General Electric states that the most im-
portant use of absorption in the controlling of light is in
producing colored light from white light sources:

. . . A selective-color filter is placed between the

white light source and the surface which is to receive

colored light. This filter absorbs parts of the

spectrum, and allows other parts to be transmitted

(General Electric, Light Measurement and Control,
p. 25).

Lighting Methods

I. General Classification
Kaufman and others divide the general or generic

lighting systems into three classifications:

A. General.--General lighting is that lighting
which is at "an approximate uniform level of illumi-
nation . . . over an entire area" (Kaufman, p. 10-3), as

in diffused ceiling fixtures over a large office area.

29

B. Localized general lighting.--Localized general
lighting is that lighting which is "a functional arrange-
ment of luminaires with respect to the visual task" (Ibid.,

p. 10-3), as in hanging fixtures over a work bench area.

C. Local or specific lighting.--Local or specific

 

lighting may be described as a system which "provides
lighting only over a relatively small area by the task and
its immediate surround" (Kaufman, p. 10-3), such as a desk

or piano lamp.

D. Supplementary light.l

 

II. Directing Light

 

There are three ways in which light may be directed
onto a surface or object. This is not to be confused with
the above general classifications of lighting systems, or
the methods of distribution which are to follow this
section. Light can be directed from the luminaire or lamp

in three ways:

A. Uplighting.--Uplighting is that light directed

 

perpendicular onto a surface above the fixture, such as a

ceiling.

B. Downlighting.--Downlighting is light that is

 

directed downward from the fixture onto the surface directly

 

1See Chapter IV, Structural, Portable, and

Accessory Lighting.

30

below it, usually the floor. A wall or theatrical curtain
may be down-lighted as well because an overall wash is

given to the surface.

C. Projgcting illumination.--Projecting illumi-
nation is directing light horizontally or diagonally to a

certain surface or object one wishes to illuminate.

Methods or Modes of Light Distribution
The methods or modes of light distribution are

specifically divided into five groups which are described
and drawn in the chart in "Basic Modes of Lighting," Appen-
dix A. These modes of light distribution are defined by
Kohler and Luckhardt (p. 136) as "the several fundamental
ways of using light in a room for illuminating purposes"
(Kohler and Luckhardt, p. 136). They go on to describe
lamps as being the artifacts which embody the sources of
light, while "fixtures control the light of lamps for light
purposes" (l9l§°)' They feel it is the nature of this con-

trol that determines the mode of lighting.

PART TWO: DESCRIPTIONS, FUNCTIONS, AND
MATERIALS USED IN LIGHT CONTROL

In order that the reader may gain some awareness
of the materials used in light control, their descriptions,
and their functions, the writer has prepared this infor-
mation in outline form. A detailed description of this
information may be found in IE5 Lightinngandbook, 1966

(Kaufman, ed.), pages 6-13 through 6-20.

31

A. Materials Used in Light Control
1. Glass
a) Types
(1) pressed
(2) blown
(3) rolled
(4) drawn
b) Use in Lighting
(1) control of light and other radiant energy
(2) protection of light sources
(3) safety
(4) decoration
(5) diffuse light
2. Plastics
a) Types
(1) thermosetting
(2) thermoplastic
b) Uses--Chart "Uses in Lighting of Important Resins"
3. Steel
a) Types
(1) hot-rolled
(2) cold-rolled
(3) porcelain enamel sheet
b) Uses in lighting
(1) structural capacity
(2) bars and rods in lighting equipment
c) Finishes
(1) galvanized sheet
(2) pre-painted sheet
(3) aluminum sheet
(4) plastic-coated sheet
(5) pre-plated sheets
(a) chrome
(b) brass
(c) copper
4. Aluminum
a) Types
(1) shapes
(2) sheets
b) Uses in Lighting
(1) structural parts
(2) light controlling surfaces
(a) reflectors
(b) louvers
(c) baffles
(d) decorative surfaces
c) Finishes
5. Stainless Steel
a) Types
(1) straight chrome group
(2) chrome-nickel group
(3) chrome-nickel-manganese group

B.

32

b) Uses in Lighting
(1) outdoor installations
(2) reflectors
(3) lighting equipment hardware
6. Copper
a) Uses
(1) conductors
(2) control of electrical energy used for lighting
7. Non—ferrous Alloys
a) Types and Uses
(1) brass used for decorative purposes
(2) bronze used for marine equipment

Finishes Used in Luminaires
l. Finishes Defined
2. Types
a) Organic coatings
(1) laquer for decoration and protection
(2) enamel for decoration and protection and
reflectance
(3) baking'laquer (baked clear) for decoration
and protection
(4) plastic dispersion for corrosion and abrasion
resistence and concealing defects
b) Ceramic coatings--porcelain enamels fired on glass
and metals
(1) for corrosion resistence
(2) good reflectance
(3) easy maintenance
(4) reducing brightness and increasing diffusion
c) Metalic coatings
(l) electroplating
(2) brass
(3) silver
(4) dip and spray coatings
d) Laminates
e) Chemical conversion coatings

CHAPTER III

TYPES OF LIGHT: QUANTITY AND QUALITY

Natural Light

 

I. Definition of
Natural Light

 

 

Natural light may be defined as that light which

is produced and/or emitted by a natural light source.

II. Sources of
Natural Light

 

 

The most obvious sources of natural light are the
sun and moon. The less obvious perhaps, but as much a
part of natural light are the sky and the ground. Whereas
the sun and the moon are considered direct sources of
natural light, the sky and the ground are usually referred
to as transmitting and reflecting sources, respectively.
The sun directs its light rays through particles in the
atmosphere which function as transmitters of the sun's
rays. In contrast, light rays are reflected from the
ground and may account for as much as 10 to 15 per cent
of the total daylight reaching a window area (Kaufman,

p. 7-1).

33

34
III. Availability and Variability
of Natural Light
The availability and variability of natural light
is in a constant state of flux. One notices these changes
especially during the daylight hours. Daily and seasonal
motions of the sun cause variations in the amount, di-
rection, and intensity of light. Kohler and Luckhardt
(p. 130) state:
. . . Daylight lighting is subjected by nature to
continual quantitative and qualitative change, alter-
ing its intensity and mood with the time of day and
with the seasons. . . .
In the early morning hours, just before dawn, "the

sky distributes light like fluorescent tubes, shadowless

and even" (Interiors, 1952, p. 92). Upon the rising of

 

the sun, "it is satisfying incandescent, a point source of
light that creates form-giving shadow and movement to the
earth" (EPEQ')° In the evening as the sun sets, an even
brightness is once again spread against the earth. It is
this ability of daylight to change that gives it "its first

appeal" (Interiors, 1950, p. 118). The IE8 (IE8 Code,

 

1961, p. 35) supports this viewpoint when they state:
" . . . One of the characteristics of daylight which gives
it this appeal is the constant change both in quality and
quantity creating interest and avoiding monotony."

The local terrain, landscaping, and nearby buildings
will greatly affect available light by creating shadows,
and partially or completely blocking the direct rays of

light. In addition, the degree of cloudiness in the sky

35

and rapid changes in cloud movement will affect the amount,

color, and distribution of light rays falling on a surface.

IV. Control of Natural Light

 

In order for natural light to be controlled and
used as a design medium, Kohler and Luckhardt (p. 130) feel
it is appropriate to recognize the reality of daylight
illuminating engineering. They state:

. . . daylight, which might well be called the primary
sustenance of life, has had only passing attention from
engineering science as its value in human living and
working space . . . intensive and extensive research

on daylighting is going forward on every hand, so that
we can properly speak of "daylight illuminating engi-
neering," that is owing to [due to] the lighting tech-
nicians, who have recognized that the system originally
set up for measuring and evaluating artificial light
can be applied to daylight as well.

The need for natural daylight has been recognized
in most modern provisions of law which "require that rooms
intended for continual human occupancy must receive natural
daylight" (Ibid.). This provision applies to continual
human occupancy in a residence only, not a business estab-
lishment which is not occupied continuously.

To use natural light to its fullest and best ad-
vantage, and to cause the least amount of discomfort to
inhabitants of a building, natural light must be controlled.
Listed below are five suggested ways of controlling natural
light that the interior designer might find especially
helpful. They are:

1. By the use of fabric at window areas——opaque,

semi—opaque, or translucent fabrics in lined

36

draperies, casements, and sheer draperies or
curtains.

2. By the use of glass--translucent, diffused,
or colored.

3. By taking advantage of natural architectural
features of the building itself, such as roof
overhangs or decorative grill work.

4. By the use of opaque materials-—roller shades,
Venetian blinds, wooden or plastic blinds,
shutters.

5. By the use of shields or exterior awnings.

6. By the use of landscaping and other natural
terrain.

The IE8 (IE8 Code, 1961, p. 35) has found that most
people prefer working in buildings that have good daylight-
ing, and "the importance placed on this is shown by the way
in which sites are usually planned to make the best use of
available natural light."

The IRS (222$!) goes on to suggest that there are
two types of interiors that must be considered in daylight
design and control: (1) one interior in which inhabitants
are able to move freely to the daylight, such as in the
home, and (2) one interior in which the same or similar
kinds of work are carried on over the entire area, such as
in offices or factories. In the former, the main problem
is to locate windows in relation to the function or purpose

of the room. In the latter, the problem is to provide

37

"well-located pools of light with no unduly dark zones"
(2229'! p. 35). The lighting designer must make it
possible for occupants to receive the correct amount of
light from the right direction causing the least eye dis-

comfort from sky glare.

Artificial Light

 

I. Definition of
Artificial Light

 

 

Artificial light may be defined as that light which
is produced and/or emitted by a man-made or artificial
source.

II. Sources of Arti-
ficial Light

 

 

The most common examples of artificial light
sources are the incandescent and fluorescent lights. Less
common sources are high intensity discharge lamps--mercury
vapor, Multi-Vapor,1 and Lucalox.2 Because the high-
intensity discharge lamps are more commonly used as ex-
terior lighting and in industrial settings, they will not

be discussed in any detail here.3

 

lGeneral Electric's trade name for a high ef-
ficiency vapor lamp.

2General Electric's trade name for the highest
efficiency vapor lamp.

3More information may be obtained on the high-
intensity discharge lamps from General Electric's pamphlet,
High Intensity Discharge Lamps, #TP-109, Large Lamp
Department Publication, General Electric Company, Nela
Park, Cleveland, Ohio 44112.

38

III. Efficiency of
ArtifiCial LightI

 

 

The greatest efficiency in terms of a long lamp
life or quantity of output must sometimes be sacrificed for
a shorter lamp life and better quality of output or color
rendition. Depending upon the needs of the individual or
group of individuals for whom the lighting is being de-
signed, these conflicting factors in efficiency play a
significant role in determining the lamp specifications.

IV. Artificial Light as a
Structural Element

 

 

Artificial light as a structural element in the
lighting of interiors may be considered in two ways: (1)
as an element of design, such as line or shape, which
affects form, color, and texture; and (2) as a physical
light source built into the room as a part of its finished
structure.2 At this point, we are concerned with light as
an element of design, and how this ultimately affects
people and objects in a particular space. The Residential
Lighting Conference (General Electric, 1967, p. 1) states:

. . . The emphasis now is on the environmental aspects
of lighting--its effect on texture and color--its

emotional impact on people--the way lighting defines
planes and spaces.

 

1See also Chapter I.

2See Chapter IV, Structural Lighting.

39

V. Kinds of Artificial Light

 

The kinds of artificial light most commonly used
in residential and contract interiors are incandescent and

fluorescent.

A. Incandescent light.--Since the invention of the

 

first electric filament lamp by Edison in 1879, the in-
candescent lamp, even though not the most efficient, has
been a popular source of artificial light--it accounts for
60 per cent of the United States dollars spent for large
lamps. Why is this so? Incandescent light is flexible,
and is the least expensive in terms of initial equipment

investment (General Electric, Incandescent Lamps, p. 3).

 

(See Appendix B, “Incandescent Lamp Shapes.")

The glass bulb of an incandescent lamp keeps the
air out while keeping the filling gas in. The bulb may be
clear, frosted inside, coated with a diffusing material,
or silvered or aluminized inside.

Incandescent lamps are designated by a two-part
abbreviation. The first part, a letter, indicates the
shape of the bulb, such as "F" for flame shape, "P" for
pear shape, etc. The second part of the abbreviation, a
number, indicates the maximum diameter of the bulb in
eighths of an inch. An "R-40" designation is an example
of a reflector bulb with a maximum diameter of five inches

(Ibid., p. 10).

40

The incandescent lamp is normally classified into
three major groups:

1. The large lamp group which operates on thirty
volts or more. The interior designer and home-
maker are most familiar with these shapes (see
Appendix B).

2. The miniature group which operates on less than
thirty volts. These lamps may be used in auto-
mobiles, aircraft, flashlights, or as Christmas
tree lights.

3. The photographic group, used for taking photos
and supplying projection service.

The IES states that the primary consideration of
lamp design for the incandescent lamp is that it "will pro-
duce the spectral radiation desired most economically for
the application intended or . . . obtain the best balance
of overall lighting cost in terms of the lighting results"
(Kaufman, p. 8-1). In a similar vein, Whiton (p. 681)
feels that the incandescent lamp is best designed for his-
torical settings, spot lighting effects, and portable
lamps, even though it is not as adaptable or versatile as
fluorescent light.

Because incandescent light is considered a more
concentrated and small, high brightness source, it is
suggested that adequate shielding, directional control,
and/or the use of diffusing materials be used. It is the

experience of this writer that where these provisions are

41

not taken into consideration, uncomfortable conditions,
such as heat and glare emitted by the source, are

present.1

B. Fluorescent Light.--Fluorescence is defined as

 

"the property of a material to become self-luminous when
acted upon by radiant energy, such as ultra-violet or X-
rays" (General Electric, Fluorescent Lamps, p. 6)-

The fluorescent lamp, which was developed for
practical use in 1938 by General Electric, has undergone
numerous changes and improvements since that time. One of
the remarkable improvements in light and lamp life that has
been made since 1950 is a 41 per cent increase in initial
light output while increasing lamp life as well. There
are available on the market today several standard sizes
ranging from six to ninety-six inches in length, various
shapes, and consuming from 4 to 215 watts (IpiQ., p. 3).

There are several million fluorescent lamps which
are used annually in industrial, institutional, commercial,
and residential settings. In the past decade more than
50 per cent of the electric light used in the United States
was fluorescent. It has gained its popularity in this
nation for four reasons:

1. It is a highly efficient light producer result-

ing in lower lighting costs.

 

lSee Incandescent Lampg, by General Electric's
Large Lamp Department for specifications.

 

42

2. It is very easy to maintain and possesses a
long lamp life.

3. It has a much lower heat content for visual
and thermal comfort than does incandescent and
has a relatively low surface brightness.

4. It comes in a variety of sizes, shapes, and
colors.

The most obvious distinguishing feature of fluores-
cent light is that it is a "line of light." This feature
allows it to emit its light in a diffuse manner rather than
in the directional or concentrated manner of incandescent
light. For this reason, fluorescent light is suggested
for areas that demand an even distribution of shadowless
light, and where low contrast and little or no glare is
desired. Examples of areas that demand this type of light
are offices, school rooms, and industrial task centers.

This "line of light" is most commonly a straight

line, but fluorescent light is not limited to this one
shape. It is limited only by the fact that it must have
two points between which an arc of energy must pass in
order to ignite its gases thus producing fluorescence.
The fluorescent lamp is currently available in circles,
U-shapes, panels, and a special energy distribution shape,
Power-Groove (General Electric, Fluorescent Lamps, p. 11)
(see Appendix C for "Shapes of Fluorescent Tubes).

Another important feature of fluorescent light is

that it is available in seven different achromatic levels

43

of white light and eight chromatic levels. It is also
available in special energy distributions such as the Power-
Groove. (The Power-Groove is used mostly in industrial
settings where a higher output of light is needed. General
Electric does not foresee its usage, for the present, in
residential settings.)

In selecting fluorescent luminaires, Westinghouse

(Fluorescent Lighting, p. 20) suggests that to use it to

 

its best advantage, the luminaire should be chosen on the
basis of its particular characteristics. They list eleven
specific characteristics: (1) distribution, (2) efficiency,
(3) brightness in the field of vision, (4) lighted appear-
ance, (5) unlighted appearance, (6) resultant appearance

of the lighted room, (7) ruggedness and durability, (8)

ease of installation, (9) accessibility and flexibility,
(10) maintenance and ease of cleaning, and (11) cost.

More specifically, General Electric (Fluorescent

 

Lampg, p. 8) suggests the consideration of three important
elements in choosing lamp color: (1) efficiency, (2)
color rendition, and (3) whiteness. If a designer wishes
to obtain the best color rendition, a necessary reduction
in efficiency must be taken into account.

The lamps designed for the highest efficiency and
with only acceptable color rendition in the achromatic
levels are the cool white, warm white, white and daylight
fluorescent lamps. These lamps are relatively weak in

red rendition. The lamps designed for the most natural

44

and complimentary color rendition of colored materials and
complexions, but with a resultant decrease in efficiency,
are the deluxe cool white and deluxe warm white. These
lamps tend to give a better balance in output by the addi-
tion of red light. The soft white fluorescent lamp is
used where there is a demand for light which is very rich
in red and emits an overall pinkish cast (General Electric,

Fluorescent Lamps, p. 8).

 

Most authorities agree that there are three classi-

fications of fluorescent lamps:

l. Pre-heat lamps require a few seconds for the
preheating process.

2. Instant start lamps start as soon as the cur-
rent to the lamp is turned on, thus eliminating
the need for starters and simplifying lighting
systems and maintenance. These lamps may be as
long as eight feet because the pre-heating
process is eliminated.

3. Rapid start lamps start in one to two seconds
which make it possible to dim or flash this
type of lamp. These are the most popular today
and are used most frequently in new fluorescent
lighting system installations.

Even though significant improvements have been made

on fluorescent lamps since they were first developed, one

will still find very adverse reactions to this type of

45

light. Kohler and Luckhardt aptly describe such adverse
reactions when they state:
Unfortunately, there is still a very strong prejudice
against the use of fluorescent lighting in the home
owing to [due to] early misuses . . . when home light-
ing with fluorescent fixtures is correctly executed,
it is quite impossible for the layman to tell from the
lighting what kind of source is being used . . . the
vast majority of people are very much guided by their
pocketbooks, and it is therefore wise to save on
lighting expense by using fluorescent tubes (p. 195).
One area of fluorescent lighting which has not
been discussed, but which is bound to play an increasingly
important role in our lives in the future, is that of
electroluminescence or a similar type of source. Electro-
luminescence is described by Kaufman (p. 8-43) as "A thin
area source in which light is produced by a phosphor ex-
cited by a pulsating electrical field." More simply, one
can find it used in a variety of situations--night lights,
switch plates, instrument panels, clock faces, telephone
dials, thermometers, or signs. Although it is available
in green, blue, yellow, or white and can be fabricated
easily into shapes because of its flexibility, it is
limited in its size to a 12" x 12" square. It is the hope
of current lighting researchers and manufacturers that it
will eventually become a mode for changing entire wall
areas to a desired color by the "flick of a switch." For
the present, its application is limited to locations where
general illumination is low. Two outstanding advantages

of electroluminescence are its long life and low power

consumption.

46

Quantity of Light

 

Quick, accurate, and easy seeing requires not only
an adequate amount of light, but also careful control
of light distribution. Great strides have been made
in lighting research over the past few years in measur-
ing the effects of light on sight. These researches
have clearly indicated that good lighting produces
many benefits, such as increased safety and improved
performance and greater ease of seeing (General
Electric, Light Measurement and Control, p. 3).

 

The above statement reflects the importance of
quantity and qualify of light and light distribution, and
the interrelated roles they play in planning an interior
lighting system. It should be noted that because of this
interrelation of roles, the following sections will not be
as clearly defined as previous segments have been.

Kaufman (p. 10-10) describes the quantity of
illumination as enough light to permit the quick, accurate
performance of a task. The IES handbook does recommend,
however, more specific levels of illumination for various
tasks.1

Other authors on this point offer somewhat more
concrete explanations of the quantity of light and how it
is measured. Kohler and Luckhardt (p. 119) state that,

"Just as electrical work is measured in watt-hours or kilo-

watt hours, quantity of light is measured in lumen hours."

 

lSee Kaufman, 1966, IRS Lighting Handbook for
illumination level specificatiEns.

 

47

I. Measurement of Light

The candela, lumen, footcandle, and footlambert
(defined in Chapter I) are all means by which light may be
measured. Each plays a significant role in the measurement
of a quantity of light. Victoria Ball gives an explanation
of roles played by each unit of light measurement. She

states:

. . . As this light [from one candle] travels outward
into space equally in all directions, the amount of it
which flows in a relatively limited direction is
measured on a square foot on the inside surface of the
standard sphere which has a uniformly diffusing sur-
face. This unit of measurement is called a lumen.

. . . A lumen is the measure of luminous flux or flow.
One candlepower can produce 12.57 lumens, because the
surface of a sphere of one foot radius is 12.57 square
feet.

The amount of light which shines upon any particular
area becomes less the farther that area is removed from
the light source. The amount of light at a particular
place is expressed in candles per square foot or foot-
candles.

. . . a footlambert . . . appraises the brightness
or apparent amount of light concentrated on a location
(Ball, 1965, p. 150).

The instrument used for measuring light is called
the light meter. It measures lighting levels in terms of
footcandles and has a range from 0 to 5000 footcandles
(see Figure 17, page 48).

II. Determining Levels
of Illumination

Determining levels of illumination in an area is
a second important consideration in the measurement of
light quantity. These levels are calculated by a process

called the lumen counter method. General Electric suggests

48

Spherical Surface

1 square foot
in area

Light Source

 

l candela or
12.57 lumens
output

 

 

 

Illumination

l footcandle or 1 lumen/square foot

 

 

 

Light 1 gogzrgadius
Source p

Figure l7.--Diagrams of Light Measurement

49

four sequential steps that should be followed to obtain the
optimum illumination levels:

1. Determine where the lights are to be placed
and the number of lights which are to be used.

2. Calculate the square footage of the room.

3. Multiply the room's square footage by the sug-
gested number of lumens per square foot.

4. Consult the lamp lumen index for the lumen
output of the lamp or tube desired to determine
if the number and kinds of lamps you have
chosen will attain desired levels of illumi-
nation (see Table 2).

These levels could be attained easily if no
attention was given to the quality of light (discussed
below). Pfister (1961, p. 27) states that a great per-
centage of the lamps and fixtures on today's market will
not supply the recommended number of footcandles for the
more critical visual tasks. New equipment and light sources
are badly needed to produce these levels realistically and
comfortably. Pfister does suggest, however, that this
situation may be remedied by using equipment of the best
lighting performance which is available, and supplementing
it with built-in elements (Pfister, p. 28).

A study by Gore (1963) revealed that accuracy and
speed of a task were better under high levels of illumi-

nation than under low levels. Although the difference was

50

not significant for statistical requirements, Gore does
maintain that further research to uncover objective methods
of measurement are appropriate to indicate human reactions
to quantity and quality of light. Gore's hypothesis was
that "humans perform less efficiently with lower levels of
illumination when the task requires fine lines of dis-
crimination" (Gore, p. 28). She measured the physical
conditions of blood pressure, pulse rate, and galvanic skin
response. These physical indicators of bodily responses,
she contended, could be measured and correlated to the
responses of differing lighting levels. The task employed
was to copy names, addresses, and phone numbers from a
telephone book using illumination levels varying from five

to seventy footcandles per square foot.

III. Luminance Ratios

A third consideration in planning the quantity of
light for a specific lighting system is luminance ratios
and their relationship to the zones (zones 1, 2, and 3) of

light.1

IV. The Planning of
Brightness Patterns

 

 

The planning of brightness patterns is the fourth
consideration in planning light quantity for lighting

systems. The IRS describes brightness as being determined

 

1See Chapter I.

51

by the speed and accuracy with which a task is executed,
the duration of critical vision, and the general level of
brightness in the room. The visual performance of the task
is naturally related to the speed and accuracy with which

the task is executed (IES Code, 1961, p. l).

V. Reflectances

 

Reflectances are generally considered to play a
vital role in the planning of brightness patterns. General
Electric states:

Reflectances of interior finishes not only affect
lighting system efficiency, but also influence visual
comfort. Studies of visual comfort point out clearly
that extreme brightness contrasts--between the specific
task and its immediate surroundings, and between the
task and more remote parts of the environment--can
cause discomfort and fatigue.

For prolonged work, the brightness pattern should
be well balanced. Control of the brightness pattern
depends on the directional distribution of light, and
on the reflectances of room surfaces (General Electric,
Light and Interior Finishes, p. 3). (See Table l.)

 

In relation to lighting efficiency, researchers
have found that the higher the reflectance of a surface,
the higher the utilization of light. To illustrate this
statement, a room in which all surfaces were a flat white,
would produce the highest light utilization possible. This
kind of sterile environment, however, would not be judged
desirable from a practical and psychological standpoint

(Ibid., p. 3).

52

VI. Specific Task Brightness
When planning specific task brightness, the IE8
(IE8 Code, 1961, p. 2) suggests that the following items
should not be overlooked:
l. The visual demands of the task.
2. The welfare, safety, and amenity judged
appropriate to the occupation.
3. Illumination of all working areas should not
be less than fifteen lumens per square foot.
4. There should be some uniformity of illumi-

nation over the utilizable area of the task.

VII. Brightness of General
Surroundings

 

 

After the task brightness has been determined,
other segments of the lighting system should be planned to
give proper emphasis, visual comfort, and interest.

Brightness of general surroundings should:

1. Be sufficiently high to allow the eyes to
adapt from the task to the rest of the en-
vironment.

2. Create a cheerful environment without causing
visual discomfort or distraction.

3. Provide for "visual rest centres" for

exacting detail (Ibid., p. 3).

53

VIII. Revealing Color,
Texture, and Form

 

 

Careful thought must also be given to revealing
color, texture, and form. The IES states that moderate
differences in color and texture between the task and its
background cause detail to become more recognizable and
enhance contrast in the setting. Strong contrasts, however,
should be avoided because of the distraction they can cause
to the eye (£§i§" p. 2).

Kohler and Luckhardt (p. 135), agreeing with the
IES, state:

Some uniformity of illumination is necessary. . . . A
room should not show disturbing differentials of
brightness distribution in the field of vision.

The same authors in discussing the effect of light
on the revealing of color in the home state:

In general . . . the relationship between level of
illumination, color of light and color rendition and
sense of ease . . . are of paramount importance in the
design of residential interiors (p. 195).

The IE8 (IE8 Code, 1961, p. 8) in discussing the
rendering of color, also refers to reflection character-
istics of the illuminating source as a determinant of the
appearance of colored surfaces. The Society feels that
daylight is the most pleasing source of light by which the
natural color of objects is viewed, and that artificial
light sources tend to change this appearance to a certain
degree.

Color matching is, in some occupations (such as

that of the interior designer), a critical judgment of

54

color or color comparisons. It is therefore essential
that the artificial lighting systems that are designed
(and preferred for this type of work) are designed as
Special lighting systems. The advantage of an artificial,
special-color-rendering system is that it provides con-
stant quantity and quality of light (Ibid., p. 8).

An illustrative example of a Special color render-
ing lighting system is the one employed by the Burlington
House Division of Burlington Industries. The system was
designed using the General Electric "Chroma-Line" fluores—
cent lamps which give spectral characteristics closest
to the color of noon daylight and northern skylight.

La Guisa states in Light magazine (1969, p. 3):
Mixing various types of lamps in various ratios is
expensive, cumbersome, and difficult to adjust and
maintain; whereas, the single-source approach with
fluorescent lamps locks in on one specific chosen
color objective. Critical work-a-day color appraisals,
selection and matching under a single-source system has
distinct advantages: it's quick and convenient, uses
standard luminaires and circuitry, light-color remains
uniform and there are no control adjustments or set-
tings which are subject to error (Light, 1969, p. 3).

In revealing form and texture, the IES suggests
that by changing the direction of light, both form and
surface texture can be emphasized or de-emphasized. One
might refer to this directional component as modelling.
The appearance or solidarity of a three-dimensional object

is affected by the direction from which light falls on the

object. Modelling may improve the visibility of some tasks,

55

or may give a more pleasing or grotesque appearance to an
object.

The control of glare and flicker are also neces-
sary considerations in planning brightness patterns in

lighting systems.1

The Quality of Light

 

The quality of light is as important as the quantity
of light. In determining priorities for a lighting system,
the quantity of light needed is established first, and the
quality of light must be of equal consideration to provide
a well-planned lighting system. Measurement of light,
determination of levels of illumination, luminance ratios,
brightness patterns, reflectances, brightness of general
surroundings, and the rendering of color, form, and texture
are all considerations in determining the quality of light
as well as the quantity.

In addition to these considerations, work and
family living patterns affect the quality of lighting.
Because of a substantial increase in informality and
naturalness of the family in past years, one room may be
used for several different functions; therefore, it must
be lighted to accommodate these varied activities.

Trends in housing design will also have an ultimate
effect on the quality of lighting because of the recent

tendency to reduce the total amount of wall and ceiling

 

1See Chapter I.

56

space. Many homes are being planned more openly, and there
is a desire for bringing a natural outdoor environment in-
side. For these reasons, lighting designers must provide
illumination subjectively for persons, rather than ob-
jectively lighting a specific room (IES Code, 1953, p. 3).

In schools and offices, however, the near-uniformity
of light "is usually incompatible with the intent of most
residential interiors . . . the tastes and varying eyesight
demands of the individual family necessitate various light-
ing effects" (Ipié., p. 3).

Kaufman (p. 10-10) concisely sums up the concept
of quality of illumination when he states that quality
includes three necessary items:

1. Having the ability to see comfortably--elimi-
nating direct glare, and minimizing brightness
differences in the visual field.

2. Having freedom from annoying shadows.

3. Having satisfactory illumination uniformity.

57

TABLE l.--Reflectances and approximate Munsell Values for
interior surfaces of residences.a

 

Surface Reflectance Approximate
% Munsell Values

 

Ceiling 60-90 8-9.5
Fabric treatment

on large wall areas 45-85 7-9.3
Walls 35-60 6.5-8
Floors 15-35 4.5-6.5

 

aJohn Kaufman, ed., IES Handbook (4th ed.; New
York: Illuminating Engineering Society, 1966), p. 15-2,
Figure 15-3.

58

TABLE 2.--Lumen counter method.

 

Lumens Required Per Square Foota

 

Living Room 80 per sq. ft. Bathroom 65 per sq. ft.
Dining Room 45 per sq. ft. Hallway 45 per sq. ft.
Kitchen 80 per sq. ft. Laundry 70 per sq. ft.
Bedroom 70 per sq. ft. Work Bench

area 70 per sq. ft.

 

aRecommended Minimum

LUMENS: The amount of light generated by the lamp
or the tube at the light source.

FOOTCANDLES: A measurement of light that reaches
any given surface. Footcandles are usually measured at
table tops, open books held in normal reading position,
etc., but ngp at the lamp or tube.

METHOD FOR DETERMINING LUMENS FOR A ROOM

1. Decide where lights are to be placed and the number of
lights to be used.

2. Measure area to be lighted; express in square feet,
(i.e., 15' x 20' = 300 sq. ft.).

3. Multiply square feet (300) by lumen requirement (i.e.,
80 per sq. ft. for living room) 300 x 80 = 24,000
lumens.

4. Consult lamp lumen index for individual lamp or tube
lumen output to find out if the number and kind of lamp
or tubes selected will attain the desired number of
lumens as listed above.

Examples:

One 20 ft. drapery cornice will take five 40-watt Home-

line tubes at 1,840 lumens per tube. . . . . . 9,200
Two 75-watt recessed R-30 spotlights (over piano)

at 770 lumens per lamp . . . . . . . . . 1,540
Two 3- light (100/200/300) lamp (pair of table

lamps) at 4, 660 lumens per lamp. . . . . . . . 9,320
One 3- -light (50/100/150) lamp (chair side table

lamp) at 2,130 lumens per lamp . . . . . . . . 2,130
Four 60-watt lamp (in desk lamp) at 840 lumens

per lamp . . . . . . . . . . . . . . . . . . . . 3,360

 

TOTAL Desired 24,000 Actual lumens 25,500
LUMENS Desired 80 per sq. ft. Actual lumens 85

 

Note: Material adapted from General Electric Com-
pany, Nela Park, Cleveland, Ohio

CHAPTER IV

STRUCTURAL, PORTABLE, AND ACCESSORY LIGHTING

Structural, portable, and accessory lighting may
be classified as three general types of lighting which
employ different luminaires, construction techniques, and
methods of distribution. It is a necessity that lighting
designers be familiar with each of these lighting types,
how they function, and where they should be placed in order
to assist the lighting designer in creating the best possi-

ble lighting system.

Structural Lighting
It is of utmost importance that structural lightl
be an integral part of the initial planning of a building
(whether it be an office building, home, or industrial
setting) so that the lighting and the building may function
together as a total unit. There has been a growing "de-
pendence on lighting to enhance and unify the esthetic

and functional properties of the contract [and residential]

interior" (Contract, 1963, p. 40).

 

1See Appendix D for structural lighting types.

59

60

I. Definition of Structural
Lighting

Structural lighting may be defined as "the term

 

used by lighting designers to describe light sources built
into the home as a part of its finished structure" (General
Electric, Residential Structural Lighting, p. 2). It may
be referred to sometimes as architectural or built-in
lighting. Structural lighting also denotes a custom de-
sign and installation to fit a particular situation (Epig.).
It is not limited to use, however, in a residential setting.
II. Considerations Pertinent to

Analysis and Placement of
Structural Lighting

 

A. Function.--Function is the first consideration

 

in the analysis and placement of structural lighting.

1. One of the major functions of structural
lighting is to enhance and light the walls and
ceiling of the room in which it is placed.
Lighting designers feel that this is important
because walls and ceilings account for approxi-
mately 75 per cent of the room surfaces. Two
examples of this type of structural lighting
which enhance and light walls and ceilings are
cove and valance lighting, discussed below.

2. Another function of structural lighting is to

provide for general lighting such as that found

61

in offices or areas that demand a more even
distribution of light (Ibid.).

Nielsen states that there are many functions of
"designed light" which could apply to structural lighting
as well:

. . . It must obviously illuminate the activities re-
quiring illumination. It must enlarge or minimize
space when required. It must enliven and emphasize
the best architectural and decorative details of any
given space while underplaying, or even eliminating,
the undesirable features. It must also serve to
establish the desired mood, be it gaiety, solemnity,
grandeur, or pleasure (Contract, 1963, p. 40).

B. Area.--The area in which the structural light-
ing is to be placed is a second consideration in the analy-
sis and placement of structural lighting. Three elements
of area should be considered:

1. The architectural features and their placement
in the area, such as windows, fireplaces,
stairwells, ceiling beams, soffits, etc. These
features will determine construction techniques,
luminaire selection, and light distribution
methods.

2. The area arrangement, such as natural traffic
paths and how they determine furnishing
arrangement, focal points, etc.

3. The appropriateness of the lighting element to
the area which determines luminaire selection

and method of light distribution. General

Electric states:

62

Because structural lighting is built right into walls
and ceilings, it can be designed to blend with any
period decorative motif or color scheme. It can blend
or contrast with its background. Since it has very
little styling, structural lighting does not become
dated in appearance (General Electric, Residential
Structural Lighting, p. 2).

 

 

III. Kinds of Structural
Lighting

Most lighting authorities agree that there are
seven basic types of structural lighting which may be
applied to residential or commercial interiors. These
basic types of structural lighting are generally classified
as: (a) valance lighting, (b) cornice lighting, (c) wall
bracket lighting, (d) cove lighting, (e) soffit lighting,
(f) luminous ceiling panels, and (g) luminous wall panels.1
Other authorities also include recessed, semi-recessed,

adjustable, or any other custom designed and/or installed

luminaires.

A. Valance lighting.--Va1ance lighting is always

 

connected with a window. Light is directed both downward
over the wall and draperies and upward over the ceiling.
Valence faceboards can be as decorative as desired, and
should always be painted a flat white on the inside in
order to reflect and utilize all possible light. Fluores-

cent light is recommended for valance lighting.

 

1See Appendix D.

63

B. Cornice lighting.--Cornice lighting is placed

 

where the ceiling and wall meet. All light is directed
downward and will give a dramatic effect to walls, textures,
wall coverings, draperies, pictures, or other wall hangings
below it. Because cornices give the illusion of greater
ceiling heights, they are ideal for rooms with low ceilings,
such as basements or recreation rooms. Both incandescent

and fluorescent light may be utilized in cornices.

C. Wall bracket lighting.--Wall brackets are of

 

two basic types--high and low. They are considered by
General Electric to be "probably the single, most useful
structural lighting device" (General Electric, Residential

Structural Lighting, p. 5). Their construction differs

 

depending on whether they are to be used to provide general
light (high brackets) or specific light for tasks (low
brackets) which are performed close to the wall. Fluores-

cent light is most commonly used.

D. Cove lighting.--Cove lighting directs all of

 

its light upward to the ceiling where it is in then re-
flected back into the room. Cove lighting sometimes is
referred to as "indirect lighting." Because cove lighting
provides very uniform and relatively flat, lifeless light,
it should be supplemented with other luminaires (lP£Q°r

p. 12). Fluorescent light is suggested for most cove

installations.

64

E. Soffit lighting.--Soffit lighting is lighting

 

that may be designed into the space provided by the archi-
tectural soffit--"The underside of any architectural mem-
ber . . . " (EPAQ'I p. 9). The two basic uses of soffit
lighting are: (1) to direct light downward onto a hori-
zontal surface such as a counter tOp, and (2) to direct

light outward to a vertical plane such as the face.

F. Luminous ceiling_panels.--Luminous ceiling

 

panels provide an even distribution of light near the ceil-
ing level by using translucent diffusers beneath fluores-
cent lamps. They create a sense of spaciousness thus making
them especially suited to kitchens, bathrooms, recreation
rooms, entryways, and even dining areas. In designing the
luminous ceiling panel, the lighting designer should con-
sider the room size, room proportion, and intended use of
the room. "An entire ceiling, however, need not be lumi-

nous to be effective and attractive" (Ibid., p. 10).

G. Luminous wall e1ements.--Luminous wall ele-

 

ments are similar to luminous ceiling elements in their
construction, but differ in their location, the wall.
Luminous wall elements tend to possess high brightness
levels which may be distracting to the eye after prolonged
periods of time. These high brightness levels can be re-
duced to a comfortable level by: (1) using dimmers on the

lamps, (2) masking part of the lamp with black electrical

65

tape, (3) using a dense patterned diffuser, and (4) using

an overlay of grillwork on the diffuser (Ibid., p. 13).

IV. Application of Structural
Lighting to Interiors

 

It is the responsibility of the lighting designer
(whether that person be an interior designer, architect,
or illuminating engineer) to determine how structural
lighting for a specified area is to be applied to that
area. That person must be familiar with the above, similar,
or more detailed information if the structural lighting
used will function to meet the needs of the individuals
in the space, and will function as a design element in that
space. There is no simple or short formula for success
in designing and applying structural lighting to an area--
it necessitates the use of available resources, materials,

and skills.

V. Aesthetic Design Factors

 

Aesthetic design factors are directly related to
the functions of structural lighting (see II, above).
Therefore the lighting designer must first know how differ-
ent structural lighting functions before he can make any
decision involving the design of the lighting element.

VI. Special Effects with
Structural Lighting

 

 

Special effects with structural lighting are limited

only by the creativity of the lighting designer. If the

66

designer of the lighting system is somewhat unsure what
the ultimate outcome of the design will be, he should not
hesitate to consult with a lighting consulting firm or

illuminating engineer.

Portable Lighting

 

A well-designed portable lamp slights neither its
functional nor decorative role. It will provide the
amount of light needed for a seeing task, and at the
same time be decoratively correct in its setting
(General Electric, See Your Home in a New Light, p. 6).

 

The above statement reflects the intent of the
portable lamp. It is unfortunate, however, that the same
statement does not reflect how a major portion of the lamps
on the market today are designed. Portable lighting is
perhaps the most neglected area of lamp design. While
structural lighting has, for the most part, kept pace with
ever-increasing demands for better lighting, portable lamp
manufacturers have failed to meet the needs of the con-
sumer. It is also unfortunate that the unknowing consumer
is the victim of a manufacturer's desire to sell a product
rather than design a well-functioning, decorative lamp.
The IES states that portable luminaires are practical and
effective only if they coordinate overall artistic design
and technologically good lighting design (IES Code, 1953,

p. 9).

67

I. Definition of Portable
Lighting
Portable lighting is that lighting which may be

 

moved from one place to another according to the demands
of the task and the needs of the individual. Portable
lamps should be used where there is a task to be performed,

and should be used only to supplement structural lighting.

 

Too often portable luminaires are the only sources of
light in a room. They are not designed to provide all the
general illumination, but only contribute to it for mood
or to enhance an area. Most portable lamps spread their
light in an area as small as "forty to fifty square feet"
(General Electric, See Your Home in a New Light, p. 7)
(see Appendix E).

II. Considerations Pertinent to

the Analysis and Placement of
Portable Lighting

 

 

A. Function.--The first consideration is function.

 

In order for a portable lamp to function properly, it must:
1. Be placed correctly (see C. below).
2. Utilize the correct shade--"The shade should be
deep enough so that you never look into the
light source from either above or below" (Hpnsg

Beautiful, 1953, p. 61). The shade should be

 

almost as wide at the top as at the bottom so
that some of the light contributes to the

general illumination of the room. Translucent

68

shades are preferred as long as the shade does
not reveal the "bulb" as a large, bright spot.
If an opaque shade is desired, the outside of
it should be approximately the same value level
as the nearest wall (Ibid.).

3. Utilize the right kind of lighting equipment.
A high quantity of light being emitted by a
portable lamp does not necessarily mean that
this light is the best quality. If glare or
high brightness at the source is evident, a

diffusing bowl or reflector lamp is recommended.

B. Color.--A second consideration in analyzing

 

and placing a portable luminaire is color. The color of
the light should blend well with daylight to avoid notice-
able color differences. Also it should be acceptable at
the illumination level which will prevail at night (IES

Code, 1961, p. 39).

C. Placement.--A third consideration in analySis

 

and placement of portable luminaires involves the area in
which the luminaire is to be placed. The activities which
are carried on in the room and the architectural layout will
determine the furniture arrangement in the space. The
furniture arrangement, in turn, will determine where the
task areas will be located. The kind of task and its
location must be known before the portable luminaire can

be placed properly.

III.

69

Kinds of Portable Luminaires

Recently, portable luminaire classification has

been defined less rigidly than of fifteen or twenty years

ago.

Contract magazine states:

There is greater freedom of design, a more experi-
mental attitude toward component materials, and less
rigid adherence to prescribed categories in the new
portable lamps and lighting fixtures . . . (Contract,
1963, p. 22).

There are two broad categories which most authori-

ties will still agree upon--the floor lamp and table lamp.

There are, however, almost as many variations of these two

types of portable luminaires as there are lamp designers.

Generally, the table lamp differs from the floor lamp in

height, although there are exceptions to this in contem-

porary portable luminaires. Lamp heights are based on

average eye heights for both men and women:

IV.

Women: 40" seated in lounge chair; 61" standing
Men: 42" seated in lounge chair; 64" standing
(General Electric, See Your Home in a New Light, p. 6).

 

Application to Interiors

 

The design of the fixture should suit that of the
interior as a whole, and so we require new fixtures
that are totally integrated with the construction of
the room. This is a beautiful and fascinating problem
which the designer can solve satisfactorily . . .
(Kohler and Luckhardt, pp. 194-95).

The above quotation aptly describes the challenge

which faces the lighting designer, particularly the interior

designer, in applying portable luminaires to interiors.

There are three general ways in which the interior designer

70

can help to harmonize portable luminaires with their sur-
roundings:
l. Harmonize styles, colors, scale, and materials.
2. Match bases with matching shades (lamp sizes
and type will vary).
3. Match shades with individual bases (General

Electric, See Your Home in a New Light, p. 7).

 

Whiton (p. 680) states in Elements of Interior

 

Design and Decoration:

 

A room that is to be decorated in any of the his-
toric styles should be equipped with such of the newer
forms as may be adaptable, providing they do not con-
flict with the harmony of style of the room.

The interior designer has the responsibility of
selecting portable luminaires which will function for a
specific task as well as adding to and becoming an integral
part of the aesthetics of the room. Some interior designers
find it difficult to locate appropriately styled lamps for
some interiors, thus requiring a custom design. Many will
wire artifacts which they have found for portable lumi-
naires and will design custom lamp shades for them.

Luckiesh, a noted illuminating engineer and author,
states that some portable luminaires are "at best . . .
only an object in the entire setting" (1925, p. 74). He
does not feel that the function of the lamp is taken into
consideration when the lamps are designed. He states

further that "The lighting fixture remains a more or less

vitalized ornament" (Ibid.).

71
V. Effects of Portable Lighting
in the Interior
Most authorities agree that the appeal of portable
lighting is in its ability to contribute a certain mood
and atmosphere to the room. General Electric states: "The
warmth and graciousness it radiates is not to be had from

any other light source" (See Your Home in a New Light,

 

p. 6).
Portable lighting should give a soft glow of light
rather than harsh or glaring illumination which could be

distracting or harmful to the eye.

Accessory Lighting

 

Up to this point, structural and portable lighting
have been discussed. There are, however, luminaires which
do not fall into either of these categories, but which are
not classified in the literature as fitting into any other
category. For convenience in referring to these unclassi-
fied types of lighting (such as decorative wall sconces
and chandeliers) the writer will call them accessory light-
ing.

I. Definition of Accessory
Lighting
Accessory lighting is that lighting which may be

 

placed more permanently than portable lighting, but is not
considered built-in or structural lighting. It is gener-

ally decorative in nature and may or may not be physically

72

functional. Accessory lighting could be described as

"Lighting to look at."1

II. Considerations Pertinent
to the Analysis and Placement
of Accessory Lighting

 

 

 

A. Function.--Function is the first consideration

 

in the placement and analysis of accessory lighting. Al-
though some accessory lighting, by definition, may not
serve any specific purpose, that accessory lighting which
does physically function should provide the necessary
quantity and quality of light in a specified area. It is
especially important that this type of light be free of
glare and high brightnesses if it is only used as "lighting

to look at."

B. Area.--Area is the second consideration. In
mounting accessory lighting on a wall, average eye heights
in sitting and standing positions must be considered as
they are in portable lighting. Ceiling pendant lamps or
chandeliers should be hung above eye level at a standing
or sitting position in order to reduce direct eye glare or

brightness.

C. Color.--Color of the luminaire and the light it

 

emits are the third considerations in analysis and placement

 

1Taken from a film by Lightolier.

73

of accessory lighting. The color should blend well with
daylight and nightlight, and should enhance the decor of

which it is a part.

III. Kinds of Accessory Lighting

 

Because of the decorative and/or functional nature
of accessory lighting, there are many variations of acces-
sory luminaires. Some of these variations are; wall mounted
sconces; pendant luminaires hung from the ceiling or decor-
ative chandeliers; combination wall and ceiling suspended
lamps (used with chains, etc.); or fiber-optic lights (see

Appendix F for examples of contemporary accessory lighting).

IV. Application to Interiors

The accessory luminaires which serve no seeing
function should be in addition to structural lighting,
and should not attempt to take the place of it. The design
of accessory lighting should also be congruous with the
historic styles of other furnishings and lighting elements
in the room. In a contemporary setting, the interior de-
signer has more freedom within which to work because of the
continuous flood of contemporary luminaires available on
the market today.
V. Aesthetic Design Factors

and the Effect ongccessory
Lightinggin the Interior

 

The design of an accessory luminaire will determine

what effect that light has in a particular space. If the

74

lamp chosen by the lighting designer does not reflect the
mood or emotional feeling of the room, or does not enhance
the space, it has not accomplished its goal as an accessory
luminaire. Just as other accessories, such as paintings
or sculpture are chosen judiciously, the accessory lumi-
naire must be chosen with the same care and appropriately
placed. Maguire, in Light magazine states:
Reaching the design objective requires the judicious
application of standard mass-produced equipment to
create exactly the effects my clients want. So,
obviously, the achievement of creative objectives
depends upon the understanding and use of both the

scientific and artistic foundations of lighting (Ligh ,
1968, p. 6).

CHAPTER V

NEW DIRECTIONS IN LIGHTING AND THE FUTURE

OF LIGHTING IN INTERIORS'
Contemporary Lighting Today

I. How Far Have We Come?

As long as man is a curious being, he will continue
making new discoveries, and discoveries in lighting have
not been and will not be an exception. In General Elec-
tric's Lighg magazine (1963, p. 23) the authors sum up
what has been done in the past fifty years:

. . . lighting has advanced from a preoccupation with
the efficiency and distribution of the light source

and equipment to an increased concern with the attain-
ment of optimum brightness patterns in the total visual
environment. . . .

. . . shifted emphasis from the lighting system to
design elements within the space. The appearance of
color, texture, form . . . and of people . . . which
modern design emphasizes, can be more fully appreciated
with a lighting system which in itself is unobtrusive
and comfortable (Light, XXXII, 1963, p. 23).

II. How Much Farther
Can We Go?

 

No one can predict with any accuracy what may take
place in the years to come. General Electric does feel,

however, that within five to ten years the Lucalox high

75

76

intensity discharge lamp (which gives off more than 100

lumens per watt) will hold a dominant position in in-

dustrial lighting.

It will be later that we find Lucalox

applied in offices, schools, stores, restaurants, and other

large installations. General

Electric does not as yet pre-

dict use in residences, but because of its higher lighting

levels which in turn reduces the number of fixtures and

cost, and its acceptable color quality, Lucalox does have

a future in contract installations.

Illuminating engineers, architects, and interior

designers do know, however, that lighting is becoming an

increasingly important commodity in our everyday lives and

that this trend will continue

at an ever-increasing rate.

New Innovations in Lighting

 

Appendix E show illustrations of the most recent

innovations in lighting.

It does not pretend to be an

exhaustive list of all the different types of lighting

fixtures. Its intent is only

and make him aware of what is

The Future of

to introduce the reader to

being done in lighting today.

Lighting for

 

Interior

Designers

 

I. How Can the Interior
Designer Contribute?

 

 

1. By making himself
ments in lighting

of good lighting.

become aware of new develop-

and knowing the principles

77

2. By educating his clients about good lighting

as it relates to that client's needs and
desires.

3. By refusing to accept and use lighting of

poor design and quality.

4. By planning and specifying the best possible

quality lighting available.

After discussing lighting with a number of practic-
ing interior designers, the investigator found a very real
desire on their part to become more interested in and aware
of lighting, its good and bad design features, the impor-
tance of quality and quantity in lighting, and in educating
the client in their actual lighting needs. They felt
lighting has been very sadly neglected in past years and
must now become as much a tool in good interior design as
texture, form, line, and color have been in the past. Be-
cause of the fast pace that has been set by recent lighting
discoveries, they felt that the practicing interior designer
will have a difficult task in keeping abreast of these new
lighting discoveries and designs. But they also felt that
lighting is of such significance as to warrant this chal-

lenge.

BIBLIOGRAPHY

BIBLIOGRAPHY

"A House Laced with Light." House and Garden, March, 1965,
pp. 122-29.

Ball, Victoria K. The Art of Interior Design. New York:
The Macmillan Company, 1965.

Bergson, Maria. "Color Application in Lighting." Interior
Design, October, 1957.

Cox, Warren E. Lightingyand Lamp Design. New York:
Crown Publishers, Inc., 1952.

"Easy Living Means Easy Seeing." House and Garden,
January, 1967.

Ewing, Gerald. "Creative Light Design." Interigr Design,
November, 1959.

 

Fahsbender, Myrtle. Residential Lighting. New York:
C. VanNostrand Co., Inc., 1947.

Faulkner, Raymond. Inside Today's Home. New York: Henry
Holt and Co., Inc., 1954.

Fluorescent Lighting. Cleveland, Ohio: Westinghouse Co.

Flynn, John E., and Mills, Samuel M. Architectural Light-
ing Graphics. New York: Reinhold Publishing
Corp., 1962.

General Electric. Large Lamp Department. Fluorescent
Lamps, #TP-lll, December, 1965.

 

. Large Lamp Department. High Intensity Discharge
Lamps, #TP-109, June, 1968.

. Large Lamp Department. How to Brighten Your
Home with Light, #TPC-lz.

78

79

General Electric. Large Lamp Department. Incandescent
Lamps, #TP-llO, June, 1963.

 

. Large Lamp Department. Light and Color,
#TP-ll9, August, 1967.

 

. Large Lamp Department. Light and Interior
Finishes, #TP-129, June, 1967.

 

. Large Lamp Department. Light Measurement and
Control, #TP-llB, March, 1965.

 

. Large Lamp Department. Lighting Maintenance,
#TP-lOS-R, March, 1967.

 

. Large Lamp Department. Office Lightipg,
#TP-ll4, September, 1967.

 

. Large Lamp Department. Residential Structural

. See Your Home in a New Light. Nela Park,
Cleveland, Ohio.

 

 

Gore, Janelle W. "The Discernability of the Effects of
Varying Levels of Illumination on Individuals."
Unpublished Master's thesis, University of North
Carolina, 1963.

"Hanging Lamps." Better Homes and Gardens, No. 44, 1965.

 

Illuminating Engineering Society. Artificial Light_and
Its Application in the Home. New York: McGraw-
Hill, 1932.

 

 

. "Home Lighting Ideas." Reprint from Illuminatipg
Engineering, November-December, 1961 and January-
March, 1962.

 

 

. IES Handbook. 3rd edition. New York: Illumi-
nating Engineering Society Publications, 1959.

. IES Handbook. 3rd edition. New York: Illumi-
nating Engineering Society Publishers, 1958.

. National_Technical Conference of the IES.
New York: Illuminating Engineering Sociéty,
August, 1966.

 

. "Recommendations for Good Interior Lighting."
The IES Code. New York, April, 1961.

 

80

Illuminating Engineering Society. Committee on Residence
Lighting. Recommended Practice for Residence
Lighting. New York: Illuminating Engineering
Society, 1953.

Interior Lighting Design Handbook. London: British
Lighting Council, 1966.

Jensen, J. H. "Ideas from R.L.C." Light Magazine, XXXIII,
No. 1, reprint.

Kaufman, John, ed. IES Handbook. 4th edition. New York:
Illuminating Engineering Society, 1966.

Kohler, Walter, and Luckhardt, Wassili. Li hting in
Architecture. New York: Reinhold Publishing Co.,
1959.

LaGiusa, Frank F. "Realism in Color Viewing." L'ght
Magazine, XXXVIII, No. 3 (1969).

"Lamps and Accessories." Home Furnishings Sales Training
Booklet. Austin, Texas: University of Texas,
Division of Extension, Distributive Education
Department.

Langewiesche, Wolfgang. "Good Seeing." House Beautiful,
July, 1953.

Larson, Leslie. Lighting and Its Design. New York:
Whitney PubliCations, Inc., 1964.

"Lighting--Part I." Interiors, CX, No. 4, (November,
1950).

"Lighting-~Part II." Interiors, CXII, No. 4 (November,
1952).

Lindgren, Kenneth A., ed. Light, XXXVIII, No. l & 2
(1969).

Luckiesh, Matthew. Lightinngixtures and LightingEffects.
New York: McGraw-Hill Book Co., 1925.

Maguire, John F. "Lighting: The Design Dilema." L'ght
Magazine, XXXVII, No. 2 (1968).

National Academy of Sciences. Natural Resource Council.
Building of Illumipation--The Effect of New
Lighting LeveIs. Cleveland, Ohio: National
Academy of Sciences, 1959.

81

Nielsen, Bodil. ”Designed Light." Contract, February,
1963.

Pfister, Magdalene E. "An Exploratory Study of the Effects
of Lighting Upon Space, Form, Color and Texture
and the Application of Such Study to the Lighting
of Residential Interiors." Unpublished Master's
thesis, Cornell University, 1961.

Phillips, Derek. Lighting in Architectural Design. New
York: McGraw-Hill, 1964.

 

Reedy, Jerry. "Brighten Your Home with Built-In Lighting."
Better Homes and Gardens, February, 1968.

 

Sauer, Ellen, ed. Ligpp, XXXIV, No. 3 (1965).
. Ligpp, XXXIV, No. 4 (1965).
. m, XXXIII, No. 2 (1964).
. £13115, XXXIII, No. 3 (1964).
. m, XXXII, No. 1 (1963).
. piggp, XXXII, No. 2 (1963).
. Ligpp, XXXII, No. 3 (1963).
. £91, XXXII, No. 4 (1963).

Subcommittee on Lighting. Myrtle Fansbender, Chairman.
Lighting . . . Keyed to Today's Homes. New York:

I

IIIuminating Engineering Society, 1960.

"Way-out Lighting." Interiors, September, 1968.

 

Whiton, Sherrill. Elements of Interior Design and Decor-
ation. PhiladeIphia: J.B. Lippincott Co., 1963,
fl
reprinted 1965.

 

APPENDICES

APPENDIX A
BASIC MODES OF LIGHTING

[Adapted from Walter Kohler and Wassili Luckhardt,
Lighting in Architecture (New York: Reinhold
Publishing Co., 1959), Figure 19: "Basic modes
of lighting," p. 136.]

82

 

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mo mmmuswoumm

 

 

 

 

 

 

APPENDIX B

INCANDESCENT LAMP SHAPES

[General Electric, Incandescent Lamps, #TP-llO,
Large Lamp Department, Nela Park, Cleveland,
Ohio, p. 10.]

 

84

/—————\
(is J
S

Straight
PAR

P

Pear

P

Parabolic Aluminized GA

 

 

 

 

 

 

Reflector

S
; Globular
F

P
Flame Pear ‘\\\\\‘~_—”’///7
Shape Shape

R

Reflector (//—\\\

 

 

 

 

 

 

A Straight
Arbitrary Slde J

 

 

T
B Tubular

APPENDIX C

SHAPES OF FLUORESCENT TUBES

[General Electric, Fluorescent Lamps, #TP-lll,
Large Lamp Department, Nela Park, Cleveland, Ohio,
1965, p. 11.]

 

Circline

A.
B.
C.
D.
E.

85

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Panel

Tubular

High output slimline
Encased slimline
Pre-heat rapid start
Power groove

U-shape

 

 

 

 

 

 

APPENDIX D

STRUCTURAL LIGHTING TYPES

[Adapted from John Kaufman, ed., IES Handbook,
4th edition, New York: Illuminating Engineering
Society, 1966, pp. 15-14 and 15-15.]

 

86

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Valance Lighting

1.

 

 

 

 

 

 

 

 

 

 

 

 

 

Cornice Lighting

 

 

 

2.

87

 

 

Law
9 ,1:

M ‘

3. High Wall Bracket Lighting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

—

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

hum- ®t€\_ Ill
H l

 

 

 

 

 

 

 

 

 

 

4. Low Wall Bracket Lighting

6.

 

Soffit Lighting

 

88

as we

 

 

[girl .8

 

5.

Cove Lighting

 

 

 

89

 

\ \ \ /
\\, \ / /

w

/\ .

 

 

 
  
  
    

 

 

 

 

 

 

 

 

 

 

 

 

 

J

,
3v" -

.57ng
W ‘

     
     

 

"f/

7. Luminous Ceiling Panel Lighting

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8. Luminous Wall Panel Lighting

APPENDIX E

PORTABLE LIGHTING MEASUREMENTS

AND PLACEMENT

90

Portable Luminaire Placed Behind
Seated Person

 

-_ ____________ J

 

42ll_49" I

L) = r”)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L_26"—.u‘

   
 

42"-49"

 

%———15"—~ k———-26"-—-‘

91

Portable Luminaire Placed Beside
Seated Person

_ __ __ -F

 

 

 

 

 

 

 

 

 

 

 

 

. -- O

 

 

'1—

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-p---
fi-d)-— -4)

 

 

 

+— 15"_d

 

 

38"-42"

 

 

 

 

 

 

 

 

 

 

 

f-Pd-—- h-----

92

Portable Luminaire Placed at Desk in
Front of Seated Person

77 2:

1‘" 1L f"
14" 14"
L- L-

J! J

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

g*-- 30W———~;
I

 

 

 

 

 

on -—-f'--
15"

 

 

 

 

 

 

 

 

 

 

 

 

93

Portable Luminaires Placed at Either Side
of Vanity with Person Standing

'h—_36"'——.'

in] _____ 4

22"

l
J 4:3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Portable Luminaires Placed at Either Side
of Vanity with Person Seated

r———'36" -—-'«

 

 

 

 

M}... F]

15"
1

l;___l

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

94

Portable or Accessory Luminaire Placed Over Bed
(may be ceiling or wall hung)

 

 

 

 

 

 

 

 

Portable Luminaire Placed Beside Bed

 

 

 

 

 

 

 

 

 

 

APPENDIX F

CONTEMPORARY PORTABLE AND

ACCESSORY LIGHTING

95

Contemporary Portable Lighting
[Habitat, Inc., New York, N.Y.]

 

 

 

 

 

 

‘\4

 

I

Q) /

 

 

 

 

 

 

 

 

 

 

 

 

Floor Lamp N
#9540 U

Floor Lamp Floor Lamp
#9552 #9592

 

W

 

 

 

 

 

 

 

 

 

 

 

 

/

Floor Lamp Floor Lamp
#9570 #9671

96

Contemporary Portable Lighting
["Stemlites," Design Line, Inc., El Segundo, California]

 

 

 

 

 

 

 

 

97

Contemporary Accessory Lighting
[CGI, Inc., New York, N.Y. and Poly-Optics, Inc.,
Santa Ana, California]

-" I
‘x

\
/ I
I

 

"Starfire" line

Fiber-optic light
by CGI, Inc.

 

 

#119

"Atlantis"

Fiber-optic light
by Poly-Optics, Inc.

 

 

 

J
HH2533 4750 4