The aesthetics of lighting

Abstract

The article presents reflections about connections between lighting and aesthetics. It presents the authors’ vision of the problem taken from their own experiences and knowledge in the field of lighting technology and general knowledge about aesthetics. Three aspects of the problem in question were identified in the article: aesthetics of illuminated objects and lighting equipment while it is switched on and off. One of the particuarly important matters of aesthetics is equipment while it’s turning on, because, so far, this problem was not clearly discernible. © 2017, Wydawnictwo SIGMA - N O T Sp. z o.o. All Rights Reserved.

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Wojciech ŻAGAN1, Mariola KOWALSKA2
Politechnika Warszawska, Instytut Elektroenergetyki (1), Politechnika Warszawska, Instytut Elektroenergetyki (2)
doi:
The aesthetics of lighting
Abstract. The article presents reflections about connections between lighting and aesthetics. It presents the authors' vision of the problem taken
from their own experiences and knowledge in the field of lighting technology and general knowledge about aesthetics. Three aspects of the problem
in question were identified in the article: aesthetics of illuminated objects and lighting equipment while it is switched on and off. One of the particuarly
important matters of aesthetics is equipment while it’s turning on, because, so far, this problem was not clearly discernible.
Streszczenie. Artykuł przedstawia rozważania autorów na temat związku estetyki i oświetlenia. Pokazano spojrzenie autorów wypracowane na
bazie doświadczenia z zakresu techniki świetlnej i ogólnej wiedzy z zakresu estetyki. Dostrzeżono trzy aspekty problemu: estetyka obiektu w
następstwie oświetlenia, estetyka opraw oświetleniowych przed i po załączeniu. Ważna jest również nie zauważana dotychczas kwestia estetyki
włączników instalacyjnych.(Estetyka oświetlenia)
Keywords: lighting technology, aesthetic of lighting.
Słowa kluczowe: technika świetlna, estetyka oświetlenia.
Introduction
Electric lighting is regarded as a technical activity,
which, depending on the object of the application, must
meet certain technical requirements and be non-fatiguing
for the eyes. This technical-ergonomic look at lightning is
more frequently replenished with an aesthetic quality
assessment, as the light significantly affects the aesthetic
experience, creates the mood, stimulates, motivates and
calms. Today, electric lightning has either practical and
aesthetic function at the same time or only one of them. It
has a practical function, if it properly illuminates the object,
making it visible at the appropriate level. When it comes to
aesthetic function, it means that the lightning serves only to
create a particular effect or mood. The concept of aesthetic
lighting can also refer to the used lighting equipment such
as luminaires, which when shone, can cause positive
experiences by their appearance and a characteristic
distribution of luminance. On the other hand, when
extinguished, they have a function of an attractive element
of an interior thanks to their interesting forms.
De gustibus non disputandum est
It appears to be impossible to unequivocally state
whether the lighting is nice, because everyone likes
something different. It is widely believed that sodium lighting
is unattractive, because it narrows the reception of natural
colours - especially green[6]. However, some argue that this
type of lighting creates a warm ambience. It is obvious that
in every society there are tendencies towards certain tastes.
They are conditioned by the culture, traditions, advertising,
trends and the mass media. Nevertheless, the final
assessment is always individual. It is well known that is
easier for people to determine something that they do not
like, for example because it is unpleasant to look at.
Another example is glaring light which will be uncomfortable
even in the most beautiful lamp. If it comes to relaxation
time, it is obvious that nobody can do it in the bedroom
which is too much illuminated. Contrarily, insufficient light in
the workplace makes it difficult to perform particular actions,
affects a visual fatigue and causes discomfort. People also
do not like when the paintings at art galleries are too hard or
too poorly lit, because it interferes with their perception of
art.
There is an opinion that circulates among the lighting
industry. It says that an aesthetic lighting is one that gives
the effect, but whose source cannot be seen. However, this
is a relatively simplified thinking about the aesthetics of
lighting. The aesthetic effect must be guaranteed, even if
you cannot see the source of light, because one of its
major functions is the induction of emotions. It seems, that
the most appropriate way to characterize what the
aesthetics of the lighting is, is to look at the issue through
the prism of generally understood aesthetics. .
The aesthetics of lighting - general features
In accordance to the theoretical definition of the term
‘aesthetics’, it is understood as the preservation of
proportion, moderation, relevance, usefulness and
harmony[4]. The meaning of this term is sometimes
described in short – aesthetics is the truth and good [5]. The
issue of aesthetic lighting should be analysed in two
different categories: an aesthetic effect (the object’s
appearance as a consequence of lighting) and aesthetics of
a device (lighting – fixture, lenses, placing). While
assessing the aesthetics in automotive lighting, the
attention should be paid to the aesthetics of hardware. The
effect of an automotive lighting is difficult to predict,
because it depends not only on the characteristic of a
reflector but also on the course of the road and its ambient.
In the illumination of various objects, one has to put more
attention to the effect of the illumination rather than to
aesthetics of the object itself. When it comes to an
illumination of the interiors, both categories of the aesthetics
of lighting are equally important.
Bearing in mind the general definition of aesthetics and
its importance in the sphere of the electric lighting, it should
be understood as the combination of certain characteristics
such as:
•the ratio of luminance (gentle and uniform luminance
distribution),
•the harmony of colours, luminance distribution and the
arrangement of lighting fixtures,
•the moderation of the levels of lighting: the luminance,
the number of luminaires and the number of lighting
accents,
•the appropriateness (the relevance of the choice of
different solutions and characteristics),
•the utility (serving a specific function).
Having right proportions in lighting means:
•having a ratio between the brightness of certain
accents and the brightness of general lighting,
•having a ratio between the luminance of the luminaires
and the ceiling,
•having a ratio between the luminance of the working
surface and the brightness of the walls and the ceiling,
•having a ratio between the size of luminaries and the
size of the interior,

•having a ratio between the size of the shadows and
illumination.
The harmony in lighting can be expressed by:
•the harmony in the arrangement and the distribution of
colours used for lighting,
•the harmony in the luminance distribution (avoiding
strong contrasts and unreadable "designs" of the spots
of light and shadows, the use of regularity,
repeatability, predictability),
•the harmony in the arrangement of luminaires
(regularity, accuracy, rhythm of light, etc.).
The balance means avoiding:
• too high lighting levels,
• excessively high luminance of the certain parts of
luminaires,
• too many points of light source,
• too rich variety of the saturation of the coloured light.
Appropriateness means:
•selecting the right type of lighting (general and
localized in the corners),
• selecting the direction of the light,
• using the proper class of lighting,
• using the right colours of light,
• using the lighting accents wherever they are needed
and allowed,
• conscious and controlled use of illumination,
• matching geometric shape of the luminaries with the
shape of the interior,
• conscious and rational use of the energy efficient light
sources (avoiding unconditional submitting to trends
and fashion).
Utility means:
•fulfilling the lighting functions as intended,
•the usability of hardware (i.e. the use of equipment
wherever it is justified),
•using luminaires suitable for the purpose (waterproof
outdoor lighting, dust-proof and flameproof lighting in
the mines).
Deadly sins in the area of lighting aesthetics:
•glare,
•disharmony,
•distortion of colours and shapes, lack of consistency,
•freedom of using coloured lighting,
•shoddiness and carelessness (bare light sources
suspended on a cable, incidental replacement of light
sources and luminaires).
In conclusion, in every society there appears to be
different preferences in the area of lighting aesthetics. The
light which intensity can be moderated is more popular than
the lighting that is exaggerated. This means that it should
adjust to the surrounding. It appears to be better to receive
a warm light than a high colour temperature light. Most
people like the lighting which is not intensive, quiet,
consistent and uniform. However, there are always
exceptions, because the final assessment is individual.
Aesthetic requirements for individual areas of lighting
The aesthetics of street lighting is mainly conditioned by
a collection of lit lanterns, which should be identical - equal
height, neatly arranged, equal spaces between them and
from the curb. After fulfilling these conditions, they form a
perfect picture – the points of light create a line, which is
parallel to the course of the road. Aesthetics of the street
lighting also include the selection of the forms of light (the
pole and housing), which is adapted to the architecture of
the nearest street environment. In the historic areas, the lit
lanterns should be stylish and should look nice when they
are switched off, which is not inconsistent with the need of
carrying out a specific photometric solid. Street lighting will
be considered aesthetically pleasing, if the luminance
distribution surface is uniform, without shadows cast by the
trees and without dark spots resulting from improper
distribution of luminance on the road (Figure 1). An
installation which generates an excessive glare is
considered as unaesthetic, because it acts on the
emotions..
Fig.1. Geometrically structured, regular line of the points of light
(optical arrangement) and high uniformity of illumination of the road
determine the aesthetics of street lighting to the greatest extent.
The aesthetics of automotive lighting
The aesthetics of automotive lighting is mainly the
headlamp and signal lamps, noticed during the day and at
night. In this area of illumination, the street lighting is so
important anymore. It is significant, to form the headlamp in
a way which is aligned with the line of the body of a car.
Fig. 2. Aesthetics of the automotive lighting should be judged solely
on the basis of the look of the headlamps and signal lamps, both in
daylight and after switching.
In previous years, an arrangement in which the line of
the body of a car was smoothly joined with the line of a lens
reflector was considered as a determinant of automotive
lighting aesthetics. Nowadays, the engineers are trying to
create the new category in this area of aesthetics.
Headlamps are more distinctive and unique (usually applies
to DRL). Particular brands can be identified by the
characteristic line of lights (oval, curved etc.).
The aesthetics of automotive lighting is also evaluated
based on the image of the back signal light when switched
on. Signal lamps are the objects of observation for the
drivers. The luminance distribution of the signal lamp
cannot be accidental, even from the point of view of the
requirements for photometric. The luminaires must meet all
the formal requirements. It is expected that the image of the
shade will present the planned figure with regularly
distributed points of light (scattering macrostructure,
reflector, matrix of LED-s, attractive light-line system,
uniformly bright and shiny surface of the output lens etc.
In the area of the aesthetics of illumination
In the area of the aesthetics of illumination the general
look of the equipment is less important than the effect of the
whole illumination. Since, by definition, it should be invisible
(the principle of hiding the reflectors and floodlights [1], [2]).
So it is totally different than in the automotive lighting. In the
illumination, the effect of lighting that complies with the
principles of illumination is considered as aesthetic. What is
more, one should bear in mind the level of the light
expressed in the value of an average luminance of the

object, as well as local accents (keeping proportions). It is
said that the skilful use of lights and shadows can give the
effect of positive emotions while looking at the illuminated
objects. If it comes to too aligned illumination, where the
object and all the details are equally clear and ‘flat’ at the
same time, it is described as unaesthetic. (Figure 3)
Fig. 3. The illumination is considered as aesthetic in such projects,
where both – light and shadow are used at equal level (on the
left).The object which is fully illuminated frontally is considered as
unaesthetic (on the right).
In frontal illumination, the objects lose their plasticity.
Situations, in which the shadows coming from the details
are too deep and cover a substantial part of the facade are
also not welcomed. In addition, too much usage of coloured
light, especially with the high saturation and multiplicity of
shades are not good either. They are not creating the
proper associations with the nature and the function of the
object. Taking care of details and paying attention to all the
technical details and conditions of the light sources used in
the illumination is also of high importance. A single not
functioning reflector may destroy the order and the
consistency of the illuminated object and cause distortion.
Fig. 4. Appropriateness in lighting also means the suitable
connection between both – aesthetic and technical characteristics
used to illuminate the object or space.
Lighting in public spaces
Lighting in public spaces, as well as in interiors, is the
largest area of the application of the artificial light (electric
light). It seems that the effect of illumination and the form of
lighting equipment are of equal importance. In large public
places, it is necessary to have many points of light or,
alternatively, a big chandelier. It appears that this feature of
public places shows a whole range of implications directly
related to aesthetics: the regularity of the distribution of the
points of light, equal authentication, light distribution and
colour of light. In the area of lighting effects, it seems that
apart from ergonomics, aesthetic lighting implements some
psychological effects: adequate saturation of light in the
room, spaciousness, clarity, pleasure, relaxation etc. These
effects are the result of the implementation of the
appropriate levels and proportions of luminance in the
interior. Aesthetic lighting in the interiors of the public places
is also a balance between the specular light and diffuse
light The result of this is a balance between the need of
visibility of certain details and the general lightening of the
entire interior. We can also improve the aesthetics of
lighting by baring human preferences in mind, such as
selection the colour of light and adaptation the level of
lighting to the rhythm of the day.
The aesthetics of interior lighting
First of all, the decision about which colour of light will
be the most suitable for a certain interior should be
conscious, not accidental. Secondly, the colours of lighting
in all the rooms in one interior/building should be
consistently and skilfully combined to form a coherent
whole. The main mistake in the area of lighting the interiors
is the wrong choice of the color temperature of light and
inadvertent use of the light sources which have different
shades of white in one room – it gives the effects of
imbalance and negative perception of the space. The best
light to perceive in the interiors is warm white, which
technically, can be specified as 3000K color temperature.
The use of light with higher colour temperature, and thus
colder shade of white, is reasonable in the rooms such as
the bathroom. In this way, it will look more like a sterile
place. A cold shade of white is also suitable for harsh and
minimalist designs. It appears to be difficult to describe all
the dependencies, especially because of the fact, that the
owner of the place or object is making the final decision.
Aesthetic lighting is designed in accordance with its
intended purpose. The first step should be to decide how
the general lighting should look like. It should evenly
illuminate the entire room. What is more, the light
concentrated on the ceiling (notably in larger areas) can
form a sufficiently high uniformity. This form of lighting can
be achieved by using ceiling recessed or suspended
luminaries. It is important for the light sources to have wide
beam light distribution. If it comes to complementary form of
general lighting, one can use the corner lighting, which
means lighting selected areas such as workplace, reading
space or a place in front of the mirror.
The intensity of the distribution of lighting is this parameter
which, undoubtedly, affects the aesthetic perception of the
room. However, one cannot generalize and say that non-
uniform lighting of spaces is unaesthetic. What is significant
here is the idea about some kind of uniformity of the light
spots. The lighting which causes irregular so-called light
spots, caused by a poor selection of a beam angle, its
placement and direction, is described as a dissonance.
To reduce the luminance levels and unpleasant or
disturbing glare, the light sources should be adequately
hide, so that the surface which is emitting the light does not
cause it. The luminance of the lenses should also be
moderated. The luminance distribution should be uniform
and adapted to its geometric shape. Considering the issue
of aesthetics of lighting, the aspect of design and art should
also be considered.
Lighting fixtures are the most subjective criterion of the
aesthetic of the interior lighting. We can now describe the
technical and decorative luminaires. The former ones, can
be determined by their appearance in the relation to its
function: waterproof mesh in the bathroom, vandal-resistant
wall lights in the stairwells, the dustproof luminaries in the
factories etc.. In the case of the latter ones, which are the
part of the design and sometimes serve the main element of
the interior, it is not possible to determine the aesthetic
guidelines. Currently, we have a huge variety of styles used
in the interior design and each of them is characterized by
the taste of the designer and investor. Therefore, there can
be as many views and votes for the aesthetic luminaires as
there are interior design projects.
However, there are some aspects that in some way define
the aesthetics of the fittings:
•luminaires should be aesthetic in both situations -
when they are not illuminated and also after switching,

•luminaires should match the style and the function of
the interior in which they are used,
•luminaires should have the suitable length of the
cables,
•the size of the luminaires should adequately
correspond to the size of the room.
Summary
This article is one of the first attempts to answer the
question about the aesthetics of the electric lighting. The
ergonomic criteria of the correct lighting and the safety
criteria are already known and developed. The problem of
the aesthetics of light and the lighting was so far left
somewhat aloof.
The light is an integral part of the architecture from its
beginnings. Thanks to the sun rays, fire and electric light
sources, we are able to receive the architecture through the
sense of the sight [3]. One can assume that it is impossible
to understand the aesthetics of lighting without the
knowledge of the architecture, the history of styles and the
purpose of having the certain buildings. It is all followed by
another feature of the aesthetics of lighting, which makes it
impossible to determine the rigid framework of the level of
lighting according to the architectural style. Moreover, it
appears to be an individual matter, conditioned by the
period of the uprising, geographical location, application etc.
Authors: prof. dr hab. inż. Wojciech Żagan, Politechnika
Warszawska, Instytut Elektroenergetyki, ul. Koszykowa 75, 00-662
Warszawa, E-mail: wojciech.zagan@ien.pw.edu.pl; mgr inż.
Mariola Kowalska, Politechnika Warszawska, Instytut
Elektroenergetyki, ul. Koszykowa 75, 00-662 Warszawa, E-mail:
mariola.kowalska@ien.pw.edu.pl.
REFERENCES
[1] CIE Technical Report, nr 94 -Guide for Floodlighting
[2] Żagan W., Iluminacja obiektów, Oficyna Wydawnicza
Politechniki Warszawskiej, Warszawa 2003
[3] Pallasmaa J.,The Eyes of the Skin: Architecture and the
Senses, John Wiley, New York, 2005
[4] Carr A., Hancock P., Art and Aesthetic at Work, Palgrave
Macmillan, New York 2003
[5] Adorno, T. (1997). Aesthetic Theory (R. Hullot-Kentor, trans.).
Minneapolis: University of Minnesota Press. (Original work
published 1970)
[6] Mesoptic Street Lighting Demonstration and Evaluation Final
Report, Lighting research Center, Rensselaer Polytechnic
Institute. January 31, 2008. Retrieved 2011-08-29
[7] Estreicher K., Historia sztuki w zarysie, Wydawnictwo naukowe
PWN,1973