Title – Interior Lighting of an Art Studio and Gallery …………………………………………………………………………………
Dissertation submitted by
Archit Mathur
Faculty of Architecture Manipal University Manipal
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CERTIFICATE
We certify that the Dissertation entitled “Interior Lighting of an Art Studio and Gallery�, that is being submitted by Archit Mathur, 123701264, in the VII semester
of
B.Architecture
undergraduate
programme,
Faculty
of
Architecture, Manipal University, Manipal is a record of bonafide work, to the best of our knowledge.
---------------------------------------------------------Faculty
in
charge
Director
Acknowledgement I would also like to express my hearty gratitude to my faculty guide, Ms VriddhiYadav of Manipal University, Manipal for her valuableguidance, sincere cooperation,k een interest, encouragement and constructive suggestions which helped me in completing this project.
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1 Contents 1. INTRODUCTION.........................................................................................7 1.1
RESEARCH STATEMENT...................................................................7
1.2 AIM.........................................................................................................7
2
1.3
OBJECTIVES.......................................................................................7
1.4
METHODOLOGY.................................................................................7
1.5
SCOPE.................................................................................................8
LITERATURE REVIEW...............................................................................8 2.1 Lighting objectives...................................................................................8 2.1.1 Safety and Health............................................................................9 2.1.2 Performance......................................................................................9 2.1.3 Appearance and Comfort..................................................................9 2.2
Visual Function...................................................................................10
2.2.1 Illuminance......................................................................................10 2.3.1 Glare................................................................................................12 2.3.2 Discomfort Glare.............................................................................12 2.4 Surface Colours..................................................................................14 2.5 Reflectance of Room Surfaces..........................................................14 2.6 Task Reflectance.................................................................................15 2.7 Luminance and Illuminance Distributions...........................................15 2.8 Modelling.............................................................................................16 2.9 Colour rendering and appearance......................................................16 2.10 Choice of Lamp....................................................................................17 2.11 Room Index..........................................................................................19 2.12 IS 3646-1 (1992): Code of Practice for Interior Illumination...............20 2.12.1 Lighting Engineering....................................................................20 2.12.2 Visual tasks..................................................................................20 2.12.3 Illuminance...................................................................................21 2.12.4 Luminance Distribution on Major Room Surfaces.......................22 2.12.5 Reflectances and illuminances....................................................22 2.12.6 Restriction of Glare......................................................................23
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2.13 Colour Appearance and Colour Rendering Groups of Lamps...........25 2.14
Controlling light Damage....................................................................26
2.15
Measuring Light Intensity...................................................................27
2.16
Standards for Display Lighting...........................................................29
3.1 CASE STUDY 1.........................................................................................31 3.2 CASE STUDY 2........................................................................................37 3.3 CASE STUDY 3.......................................................................................39 4 DATA ANALYSIS..........................................................................................41 4.1
From Literature Study.........................................................................41
4.1.1
From Case study 1......................................................................42
4.1.2
Analysis........................................................................................42
4.1.3
Inference......................................................................................44
4.2
Case Study 2......................................................................................44
4.2.1
Analysis........................................................................................44
4.2.2
Inferance......................................................................................46
4.3
Case Study 3......................................................................................47
4.3.1 5
Analysis........................................................................................47
FINDINGS.................................................................................................48 5.1
Lighting in a typical art studio:............................................................48
5.2
Lighting in a typical art gallery............................................................49
5.3
Findings from Visual 2012 software...................................................49
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Abstract When considering the different operating systems of a museum or gallery or any other place of art, lighting has perhaps undergone the greatest changes in recent times. Most notably these include the phasing out of inefficient incandescent lighting and the rapid development of new technologies and associated operating systems. Artwork resulting from hours and hours of contemplation, detailed work, and refinement should have the opportunity to be best appreciated through appropriate lighting. Elements within lighting play important parts in how artwork is featured and conveyed. I have developed this resource, in the form of research, case studies and analysis to assist art gallery and studio designers to identify the best longterm lighting configuration or system in future projects or/and upgrade or replacement solution for their institution.
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2
INTRODUCTION
1.1
RESEARCH STATEMENT
STUDYING ARTIFICIAL LIGHTING TECHNIQUES,ACHIEVING OPTIMUM INTERIOR LIGHTING FOR AN ART GALLERY AND AN ARTIST STUDIO. 1.2 AIM TO ACHIEVE OPTIMUM INTERIOR LIGHTING IN AN ART STUDIO 1.3
OBJECTIVES
•
Understand aims in a general lighting design of an interior space.
•
Understand the damage caused by light to the artwork in galleries and art studios and how to evade such damage.
•
To study lighting standards in studio as well as gallery design worldwide.
•
To understand the Indian scenario and study Indian standards (IS 3646-1 (1992))
•
To study some lighting systems used worldwide and how they can be incorporated in India.
•
To fill the gaps with western standards, adding on to the Indian.
•
To study lighting standards for the display of art in detail.
•
Come up with lighting guidelines in art gallery and studio design
1.1 METHODOLOGY • Understand aims in a general lighting design of an interior space by studying aspects of interior lighting such as appearance and comfort, visual function, illuminance, intensity etc •
Study the factors affecting illuminance as it is the quality of light who’s different amounts are required for perception of varied tasks. Scale of illuminance range of illuminance.
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•
Do a literature study on the ill effects of glare and how to rectify such errors in design.
•
Study the types of lamps and fixtures and the lighting requirements of different spaces, narrowing down to the types of lamps required in art galleries and studios.
•
Case study of Art Gallery of New South Wales Brett Whiteley Studio and Yale University Art Gallery collection to understand their new upgrade to LED lighting systems, how it helps in reducing costs, preserving and perceiving art work.
•
Case study of Sadie J. Valeri’s instructional art studio to understand the lighting system that best suits the studio and has least negative effects such as heat-spots.
•
Use Visual 2012 software to understand lighting system in galleries of their displays.
1.2 SCOPE This study will help design more efficient Art studios and galleries with lighting which will help improve perception of the artwork and intern improve the design process in the studio and in galleries, to better preserve and perceive the artwork.
1.3 LIMITATIONS This study is only limited to the interiors of the art gallery and the work space of an artists’ design studio. The following fields:
Exterior façade lighting
Natural lighting
User psychology
Are not included in this study.
2
LITERATURE REVIEW
2.1 Lighting objectives Lighting objectives are the clear requirements and what needs to be created to provide the right conditions for the users and the intended use. It can In this
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case, there are a different bunch of lighting requirements for art gallery and studio design, objectives include things as what type of image must be created. Lighting objectives should be established at an initial stage for a successful design. The lighting objectives are considered under three catagories:
Safety and health.
Performance.
Appearance and comfort.
2.1.1 Safety and Health Interior lighting should enable the users to see sufficiently well to work and move about in safety. The lighting should not create conditions that are damaging to user's health. This for example, requires the elimination of harmful radiation, and the prevention of eye strain, also the control of glare.
2.1.2 Performance The type of work that takes placein an interior and the characteristics of the activity together define the nature and the variety of the visual tasks. The quantity and quality of the lighting required to achieve satisfactory visual conditions depend on these tasks, ideally analysed in terms of size, contrast, duration, age of observer, colour discrimination and complexity. This is an impractical thing to do and a much more practical method is to use lighting organisation’s recommendations simply specifying what has proved to give satisfactory visual presentation in the past.
2.1.3 Appearance and Comfort The way in which a space is illuminated affects its character and the advent of objects within it. Where the creation of mood or atmosphere is primethis must be the primary lighting objective, but some attention should be given to this factor in all designs. You should attempt toweigh
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these objectives agreeing to their relative importance in an integrated approach. Quite clearly, safety objectives must never be leftunnoticed. For places, such as offices and factories, performance will normally be more key than appearance. Not all the design objectives can be articulated as measurable quantities, for example, the need to make an environment seem "prestigious", "efficient", or "vibrant". Once the lighting objectives have been defined, they must be conveyed in terms of physical parameters to form a design specification.
2.2
Visual Function
2.2.1 Illuminance Sufficiency is generally taken to imply an adequate amount of light (illuminance) both on work tasks as well as in areas where people circulate. Legislation is typically concerned with what is sufficient, which is less tedious than the recommendations in lighting guides, such as the CIBSE Interior Lighting Code, which are concerned with good practice. The schedule in the Code recommends standard maintained illuminances for interiors agreeing to the tasks involved, where the average maintained illuminance is the lowest illuminance throughout the maintenance cycle of the lighting system and averaged over the appropriate area. The appropriate area may be the whole of the interior or just that occupied by the tasks and their instant surroundings. In this case the sustained illuminance of the over-all surrounding areas of a working environment must be based upon tasks that are carried about in these areas, but should not be less than one-third of the uppermost task illuminance or problems of adaptation will thus arise. Illuminances must be increased or decreased if task details are oddly difficult or easy to see or if the task is completed for an unusually long or short time. They must be increased if blunders would have unusually serious consequences.
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Also, if the heaviest visual tasks are to be carried out by users with poor sight or an average age that is higher than normal, over 50 years, the designer would be justified in increasing the illuminance. The maintained illuminance must not be less than 500 lux for situations that involve critical colour matching. The illuminance recommendations relate to the tasks themselves that may be complex in both the shape and the position. This can cause major problems in prediction and measurement. It is generally assumed that the illuminance on the task will besimilarto the illuminance on a plane at similar angles and position as the task. This is passable for most practical purposes. It often happens that the location of the tasks is not accurately known, in which case a horizontal plane at work station height is generally taken. Where vertical tasks are involved, but their orientation is unknown, then mean vertical (i.e. cylindrical) illuminance can be used. In addition to providing adequate light for tasks to be carried out, the users must also feel that there is sufficient light. Experiments show that the connection between average horizontal illuminance and observers' assessments of how well lit the room seems is poor. Cylindrical illuminance (which is the same as the ordinary vertical illuminance - averaged over 360 degrees of rotation) is a valued measure. It gives ansign of how, randomly placed vertical surfaces would be illuminated. It also relates rationally well to the particular appearance of how well lit the room seems to be. In crude terms, the higher the average cylindrical illuminance, the brighter lit the room will seem to be.
2.2.2 Consistancy of the Illuminance Consistency of the illuminance is important for three reasons: • Excessive variations in illuminance mean that some parts get less illumination than is required, whilst others receive more than that is necessary.
• The luminance of the instant surroundings to a visual task can
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affect the visual performance and comfort. • Excessively uneven lighting is accountable to be judged individually as unsatisfactory. IS 3646-1 (1992): Codeacclaims that the consistency of illuminance, measured as the ratio of the least illuminance to the average illuminance above the task area, must not be lesser than 0.8. This isn’t to say that the horizontal illumination over the room must be perfectly unvarying. Although such lighting would confirm that the significant visual tasks could be done anywhere in the space, it implies a substantial waste of energy in giving task lighting levels in non-critical areas. Uniform lighting is, often, uninteresting; when properly applied, non-uniformity can create interest and is recurrently preferred. If non-uniform lighting is to be used, then the lighting designer should be careful to dodge excessive variation that can cause adaptation difficulties or, in the worst case, safety complications. The area which is visually surrounding the task (frequently most of the room) must be illuminated to not less than 1/3 of the task illuminance.
Through projecting the field of vision onto the ceiling surface it is possible to outline the area on which the luminaires might have a negative influence on contrast rendering. Uniformity over a task area not less than 0.8 Task area Shadows might be cast over the area of a visual task, decreasing the illuminance, causing adaptation difficulties, and creating disturbance or distraction. To avoid unnecessary shadowing in industry, where high machines or racks are often closely spaced, it is generally necessary to space luminaires less far apart than would be required to fulfil illuminance and consistency requirements.
2.3.1 Glare Excessively bright areas in the view in an interior, can separately or together damage visual performance (disability glare) or source visual discomfort (discomfort glare). Lighting systems in most of the working interiors are improbable to cause substantial direct disability glare, but a slight degree of discomfort glare is probable.
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2.3.2 Discomfort Glare Discomfort glare systems, for measuring glare for interior lighting, fall into two categories: • Define luminance limits for satisfactory luminaires • Assess discomfort glare indices for installations. The second type of system is used in UK. The grade of discomfort glare is signified by a GlareIndex, which is calculated for the settings of the installation. Keeping glare in mind, a distinction has been made amongst direct glare, producedmainly by luminaires (1), in the case of horizontal visual tasks,reflected glare (2) reflected glare for vertical visual tasks, e.g. at Video display terminal (VDT)workstations (3).
The grade of discomfort glare that can be endured decreases as the task difficulty increases, and the UK system states an upper limit for the glare index for diverse situations, selected through experience and practice to signify a standard of visual comfort suitable to most people. This is called the Limiting Glare Index. It is alluring to judge different lighting schemes by the Glare Index, but this must be done with caution. The mathematics of the Glare Index is such that no appliedimportance must be given to alterations of only one or two units between different schemes. Similarly there is little value in trying to achieve a Glare Index lesser than that
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is required. This is since the Limiting Glare Index designates the point at which, for the specific type of task activity, the lighting delivers a satisfactory standard of visual comfort. The standard will thus be acceptable once the limit is touched and supplementary reductions will not improve matters significantly but may consequence in other penalties. Despite using a different glare formula there is insignificantchange in real installations between UGR values and values of glare index in the UK system. Hence it seems that the numbers specifying limits to glare can stay unchanged.
2.4 Surface Colours It is uncommon for lighting designers to have control in the selection of room surfaces, which is unfortunate when the features of these surfaces affect glare, modelling, and lighting system effectivenessand the appearance of the room. When the occasion does arise to select colours, designers may find it best to study first how light or dark the colours should be, then select the hue, and then the saturation. Passive colours are often selected where a soothing or dignified atmosphere is essential, while strong colours and high contrasts are generally used to generate lively and exciting effects. The colour appearance of a surface is a function of the surface itself and the kind of light source. When trying to evaluate the effect that a particular light source will have on coloured surfaces, there is no substitute for a hands-on test.
2.5 Reflectance of Room Surfaces Toattain a ceiling cavity reflectance of 0.6 is quiteeasy with a flat ceiling, but may be difficult, if not impossible, when luminaires are suspended long beneath the ceiling. The upper limit of 0.7 for effective wall reflectance is also difficult to apprehend in practice, and floor cavity reflectances within the suggested ranges (0.2 to 0.4) are rarely achieved. In installations using luminaires with little or no upward light, the ceiling is illuminated by interreflected light. When the Room Index is great, most of this inter-reflection is
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from the floor, which may causedifficulties. Anextremely coloured carpet gives rise to a highly coloured ceiling, similarly variations in floor cavity reflectance cause an uneven ceiling appearance. The room surface reflectances have a straight effect upon the efficiency of the installation.
2.6 Task Reflectance Thereflectances of tasks and their background should be well-thought-out. If the outline of the task is the primary concern, then good contrast with the background is important. Where detail within the task is more important, then the contrast between the task and its background must be low to avoid adaptation problems. In which case the luminance of the direct background to a task must be no less than one-third of the task luminance. Generally the characteristics of the visual task are static and the easiest way to ensure that the background has anacceptable luminance is to vary its reflectance. 2.7 Luminance and Illuminance Distributions The relative brightness’s of the major surfaces have a significant effect on the appearance of a room. Brightness depends on luminance, but since surface reflectances are recommended it is possible to cover this aspect of appearance by recommending illuminance ratios. They will produce satisfactory results in most situations, the designer must be aware of the possible room appearance created by the relative brightness’s of the room surfaces. When well-designed uplighting is used, the ceiling can be brighter than the recommendations; firstly since there are no bright luminaires in the ceiling plane and moreover because of the on-going variation in ceiling luminance. These recommendations are not rules, but are well reinforced by experiments and experience. The lighting designer must not feel inhibited by them, but should only go outside them when the consequences of doing so are understood.
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2.8 Modelling Modelling embraces lighting effects that disclose form and texture Modelling can be articulated as a lighting standards using display illuminance ratios as a guide for degrees of modelling from ‘subtle’ to ‘dramatic’. The display illuminance ratio (DIR) is that amongst the general horizontal illuminance in the room and the value of illuminance in the plane of the body to be displayed. Higher degrees of emphasis are expected to require lower values of general lighting to avoid the necessity for excessive local display illuminance. The DIR is a measured ratio using a light meter whereas the subjective apparent brightness ratio is a guide to how people may perceive the difference between display and the background.
2.9 Colour rendering and appearance. The colour rendering and appearance properties of lamps are essential elements in lighting design. It is just about invariable a false economy to choose lamps of poor colour rendering properties for the sake of a minor price advantage on lamps that themselves are a segment of the luminaire price, even before installation costs are taken into account. If possible take the
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chance to see demonstrations of both colour rendering and colour appearance.
2.10 Choice of Lamp The selection of lamp affects the variety of luminaires available, and vice versa, so one cannot be considered without reference to the former. The elements on Light Sources will help to distinguish the performance of the main lamp types. The designer can accumulate a list of suitable lamps by refusing those that do not satisfy the design objectives. The accessibility of suitable luminaires can then be checked and the economics of the arrangementsmeasured. Lamps must have satisfactory colour rendering properties. Visual tasks needing accurate perception of colour are not common, there are many marketing situations where decent colour rendering is appropriate. The appropriateness of a lamp for a particular application is best decided by experimental test. Lamps must also provide the right colour appearance. A warm colour appearance inclines to be favoured for informal situations, at poorer illuminances, and in cold environments. A cool appearance tends to be preferred for formal circumstances, at higher illuminances, and in warm environments. It is normally undesirable to illuminate perceptibly adjacent areas with sources of significantly different colour appearance. Lamp life and lumen maintenance should be considered in combining with the maintenance policy, and it needs to be remembered that standardisation of lamp kinds and sizes within a particular site can make simpler maintenance. A simple guide to selecting a suitable lamp type is as follows: 1. Firstselect what minimum standard of colour rendering is required. Except in the case of individual applications, the CIBSE (British Standards) colour rendering classes are perfect for this purpose.
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Do not choose lamps from the appropriate class. Lamps in a better class may be more efficient or a better choice for some other purpose. As an alternative, make a note to reject any lamps that are in lower classes.
2. Now choose which colour appearance groups will be undesirable Colour temperature is usually stated in the unit of absolute temperature, the Kelvin, having the unit symbol K. Colour temperatures above 5,000K and are called cool colours (bluish white), whereas lower colour temperatures (2,700–3,000 K) are called warm colours (yellowish white through red). -Warm -Intermediate -Cool -Cold some applications that require precise colour judgement must use lamps with a specified
The CIE 1931 x,y chromaticity space, also showing the chromaticities of black-body light sources of various temperatures (Planckian locus), and lines of constant correlated colour temperature.
colour appearance (frequently cool or cold).
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3. Decide how the lighting will be controlled and how quickly light will be needed. This, when compared to the run-up and re-strike times of different lamps will define which ones are undesirable. 2.11 Room Index The utilisation factors are determined by the effective reflectance of the room surfaces and the room index. Room Index is for rectangular rooms given by:
RI=LW/Hm(L+W) where: L- length of the room W- width of the room Hm- height of the luminaire plane above the horizontal work surface or plane If the room is re-entrant in shape, for example L-shaped, then it must be separated into two or more non-re-entrant pieces which can be treated independently.
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2.12 IS 3646-1 (1992): Code of Practice for Interior Illumination
2.1.1 Lighting Engineering Criteria lightingnecessities are based on the following lighting engineering standards: - Lighting level, - Luminance distribution, - Glare restriction, Direction of incidence of light and the shadow effect, and - Colour appearance and colour rendering. A lighting fitting can satisfy the necessities laid down, only if all !he quality standards are complied with; one or other quality criterion may be given importance, depending on the nature and difficulty of the visual task or on the kind of room. Lighting requirements are established on the following criteria:
Luminance distribution
Lighting level
Glare restriction
Colour appearance and colour rendering
Direction of incidence of light and shadow effect
A lighting installation can satisfy the necessities laid down, only if all !he quality standards are complied with; one or other quality standard may be given priority, depending on the nature and difficulty of the visual task or on the type of room. 2.1.2 Visual tasks The size of the acute details of the task:
The speed at which these details have to be perceived
The desired reliability of recognition
Their contrast with the background
The duration of the visual work
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The quality requirements increase with the difficulty of the visual task. 2.1.3 Illuminance The lighting level produced by a lighting fittings is usually qualified by the illuminance produced on specified, planes. In general, this plane is the major plane of the tasks in the interior and is generally called the working plane. The illuminance provided by an installation affects the performance of the tasks and the appearance of the space. 2.1.3.1 Scale of illuminance In order to be able just to distinguish features of the human face, a luminance of approximately 1 cd/m” is essential. This can be attained under normal lighting conditions with a horizontal illuminance of about 20 lux. So 20 lux is considered as the minimum illuminance for all non-working interiors. A factor of approximately 1.5 represents the smallest significant difference in subjective effect of illuminances. Therefore, the following scale of illuminances is suggested. 20-30-50-75-100-150-200-300-500-750-1000 1 500-2 000, etc, lux. 2.1.3.2 Illuminance ranges Since circumstances may be suggestively different for different interiors used for the same application or for different circumstances for the same kind of activity, a range of illuminances is suggested for each type of interior or activity intended, of a single value of illuminance. Each range consists of three successive steps of the recommended scale of illuminances. For working interiors the middle theof each range represents the recommended service illuminance that would be used unless one or more of the aspects mentioned below apply. The higher value of the range must be used.
Errors are costly to rectify;
Unusually low reflectances or contrasts are present in the task;
Visual work is critical;
Accuracy or higher productivity is important
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The visual capability of the worker makes it necessary. The lower value of the range may be used
Speed and accuracy is not important;
Reflectances or contrasts are unusually high;
The task is executed only occasionally.
2.1.4 Luminance Distribution on Major Room Surfaces The distribution of luminance must be regarded as contrary to the design on the illuminate in the interior. It should take into account the following features:
Luminance of ceiling, walls and floor;
Luminance of the task and its immediate surroundings;
Avoidance of glare by limiting the luminance of luminaires and windows.
2.1.4.1 Luminance Distribution in the Task Area The luminance of the instant surroundings of the task should, if possible, be lesser than the task luminance, preferably not less than l/3 of this, value. This denotes that the ratio of the reflectance of the instant background of a task to that of the task itself should preferably be in the range 0.2 to 0.5. 2.1.4.2 Luminance of Ceilings, Walls and Floors The average luminance in the outer field of view should, if possible, be not lesser than 1/10th of the task luminance. 2.1.5 Reflectances and illuminances In working interior, in order to reduce the contrast between luminaires and surrounding ceiling, the ceiling reflectance should be as high as possible. In order to avoid that the ceiling may otherwise appear too dark, the ceiling illuminance must not be lesser than l/l0th of the task illuminance. In order to achieve a well-balanced luminance distribution, the ratio of the minimum to the average illuminance shouldn’t be lesser than 0-8.
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The average illuminance of the over-all areas of a working interior should normally not be less than l/3rdof the average illuminance of the task area. The average illuminance of adjacent interiors should not differ from each other by a ratio exceeding 5 : 1. 2.1.6 Restriction of Glare Glare might be caused by lamps, luminaires and windows or by the reflection of bright sources from surface with high reflectance (reflected glare). In interior lighting, discomfort glare from lamps and luminaires is likely to be more of anissue than disability glare. 2.1.6.1 Restriction of direct glare Direct glare is considered to be adequately restricted, if the average luminance of the luminaires in the critical glare range 45â&#x20AC;?< y hs where hs is the vertical distance between observers eye and the primary luminaire. The elevated scales of the glare rating G is based on the following understanding of observersâ&#x20AC;&#x2122; impressions: 0 = No glare, 2 = Perceptible, 4 = Uncomfortable 6 = Intolerable glare. Signifying quality classes from 1 to 3, for various values of illuminance. For different activities and interiors, the significance and extent of glare, limitation is different. For that reason, proper quality classes from 1 to 3 has to be selected for various values of illuminance: -Class 1 High quality -Class 2 Medium quality -Class 3 Low quality
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The luminancesrestraining curves of Diagram 1must be used for all luminaires without luminous sides and for lengthened luminous sides when viewed parallel to their longitudinal axis. The curves in Diagram II should be used for luminaires with luminous sides viewed perpendicular to their longitudinal axis. The following aspectsmust be kept in view while using the curves in Diagrams I and II:
It is assumed that the luminaires are arranged in a regular pattern in the ceiling,
They are intended to be used for working interiors only,
The curves are valid for medium to bright room surface reflectances ( ceiling reflectance of not lesser than 0.5 and wall reflectance of not less than 0.25 ), A luminaire is considered to be lengthened if the ratio of the length to the width of its luminous area is either equal to or greater than 2 : 1
Luminaires without luminous sides consist of those with projected luminous area less than 0-03 m in height
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.
2.2
Colour Appearance and Colour Rendering Groups of Lamps
The colour of light produced by a â&#x20AC;&#x2DC;near whiteâ&#x20AC;&#x2122; source can be indicated by its associated colour temperature (CCT). Each lamp type has a definite correlated colour temperature, but for hands-on use the correlated colour temperatures have been grouped into three classes. The choice of suitable apparent colour of light source in a room is mainly determined by, thefunction of the room. This may include such psychological aspects of the colour as the
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impression given of warmth, relaxation, clarity, etc, and more ordinary considerations such as â&#x20AC;&#x2DC;the need to have a colour appearance compatible with daylight and yet to provide a white colour at night. The capability of the light source to render colours of surfaces truly may be conveniently quantified by the general colour rendering index. 2.3
Controlling light Damage
We need to discoverlevel of lighting that will make it possible for visitors to see the entities well, and yet produce as minute light damage as possible. The only way to completely protect light-sensitive items from damage is to keep them in the dark; every exposure to light is to some degree damaging. Once the decision has been made to display an object, the only way to control the amount of light damage is to change the level of intensity and/or to limit the length of time on display. The Canadian Conservation Institute has created a "Light Damage Slide Rule" which makes it possible not only to analyse light damage to an object ahead of time, but also to determine the variations that would be an outcome from changing one or both factors - intensity and duration. There are various mechanical means that may be used to reduce the duration of light exposure turning off gallery lights when viewers are absent, by means of movement detectors to turn on lights automatically when someone approaches, fixing visitor-activated light switches, or using cloth covers on display cases that stand in lighted areas. Rotating works on permanent exhibition is often necessary, and although it differs with the object, a handy guideline is three months per year on display for controlled lighting environment. Accurate records of light exposure must be part of the stable records for light-sensitive objects, so that informed decisions can be made about displaying them. â&#x20AC;˘
Taking out all UV and IR dramatically retards fading and damage. Both laboratory and museum testing have confirmed that lighting systems with no UV or IR extend the show life of a minimum of 3 to 5 times, when compared to typical museum lighting.
â&#x20AC;˘
Tests of a number of lights with both widely-used ISO blue wool and fugitive dye testers in assorted colours showed some surprising results:
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1) Fluorescent lamps faded the ISO testers only 10% less than sunlight. 2) Dimmed incandescent and halogen lamps initiated fading within 4% of fluorescent lamps. 3) UV filters on fluorescent lamps only decreased fading by 30%. 4) Adding glass IR filters to halogen lamps only decreased fading by 10%. 5) Fiber optics with no UV and IR decreased fading by 80% (five times the exhibit life) compare d to fluorescent, incandescent or halogen lamps. 6) Lightly tinting fibre optics to match artefact colour decreased fading by 91% (twelve times the exhibit life) related to fluorescent, incandescent or halogen lamps. 7) Colour filtering fibre optic lighting to correctly match the colour of an artefact decreased fading by 99% (increased exhibit life by 100 times). Colour-matched lighting discontinues fading. This testing led to the science of Reflected Energy Matching. You only see reflected light and only absorbed light causes damage. Matching light colour to artefact colour does not modify appearance. Again, you only see what is reflected. What is does is eliminate absorbed energy (and damage). Hundreds of fading tests demonstrate that 2.4
Measurment of Light Intensity
With a Footcandle Meter or a Lux Meter: Light meters that change the reading straight to footcandles or lux can be ordered. They will measure whicheverI,e the incident light or the light reflected from the item. Follow the manufacturer's guidelines. With a camera light meter: The method suggested by the Canadian Conservation Institute measures reflected light. It needs a 35mm single lens reflex camera along with a built-in light meter and a white card of dimensions12" by 16". 1. Fix the camera film-speed reading at 800 ASA, set the shutter speed at 1/60 of a second.
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2. Ask someone hold the white card in opposite of the art work and at the same angle as the art work. 3. Place the camera so that the card just fills the view screen. 4. Change the aperture setting up until the camera's light meter shows a exact exposure. The following steps show how the f-stop reading relates to lux and footcandles: f4 - 50 lux or 4.6 footcandles f5.6 - 100 lux or 9.3 footcandles f8 - 200 lux or 18.6 footcandles f11 - 400 lux or 37.2 footcandles f16 â&#x20AC;&#x201C; 800 lux or 74.3 footcandles The outcomes of this method are not as precise as those of a lux/footcandle meter, but we found them to be in 3 footcandles of the footcandle meter reading.
2.6.1 Measuring Fading There are low-priced 'fadometer' cards which use standardized swatches of blue wool to measure the amount of fading. These can be used to monitor
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gallery environments either during exhibitions or, ideally, before art objects are set up. 2.5
Standards for Display Lighting
If a reflective surface is arranged transversely, luminaires can be fixed in front of the excluded ceiling zone. If a reflective surface is arranged vertically, they can be fixed next to the excluded ceiling zone.
High luminance values reflected by surfaces or objects can result in secondary glare. The luminaires should not be placed in criti- cal areas. Indirect illumination with diffuse light decreases the secondary glare. The beam should be pointed such that shadows on the work surface are avoided.
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The space from the wall for wallwashers must be at least one third of the room height. The wall offset is known by a 20 degree line extending from the bottom of the wall to the ceiling. Whereas for normal room heights the luminaire spacing is the similar as the wall offset, in high rooms this spacing must be decreased to compensate for the illuminance which is generally reduced. Wallwashers do not give ideal uniformity till at least three luminaires are used. A wallwasher in a room corner should be placed on the 45° line.
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Objects can be illuminated with light pointed from between 30° - 45° to the vertical. The more steep the incident light, the more pronounced the three-dimensionality of the illuminated object. If the angle of incidence of the light is roughly 30°, the so-called “museum angle”, this produces extreme vertical lighting and avoids reflected glare that may bother the observer. In the case of reflecting surfaces, e.g. oil paintings or portraits framed behind glass, attention must be paid to the angle of incidence of the light to avoid unsettling reflections that may arise in the viewer’s field of vision. This will also avoid any heavy shadow, e.g. photo frame shadows on the picture.
The more steep the incident light, the more clear the shadow effect. Objects can be illuminated well when the direction of light is in the middle of 5° and 45° to the vertical. The ideal direction of light for illuminating objects is at 30°. This avoids reflected glare or unwanted shadows on people or objects.
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Calculation of the ideal positioning of a luminaire for portraits on a wall – room height, observation area, size of picture and ideal viewing angle (fig. on left) are the parameters defining the ideal position of a wall-lighting luminaire. The upper edge of the picture decides the spotlight opening angle (B: 30°, C: 60°) with a fixed angle of 30°. Angles less than 30° can end in reflections at the upper edge of the picture (critical observation area). The scientific formula for calculating the distance “x” between spotlight and wall for enlightening a picture with the height “y” is: x = y tan 30°. Directional lighting accentuates exhibits, planar lighting makes for constant illumination.
3 3.1 CASE STUDY 1 Art Gallery of New South Wales Brett Whiteley Studio Context . Size of Refurbishment: Approximately 360m². Project Price Bracket: Above $200,000 Project Description: The Brett Whiteley Studio is a local gallery functioning under the Art Gallery of New South Wales (AGNSW). The LED lighting
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upgrade completed in 2014 acted as a pilot project for upcoming lighting upgrades for the larger galleries within the AGNSW. A complete LED lighting refurbishment was undertaken, as well as new LED luminaires, new track infrastructure, and a new DALI lighting control system. All outdated lighting tracks, track fixed luminaires, security lighting, emergency and exit lighting were substituted with an integrated system. Previous Installation:
Track layout and offset from the wall was not ideal for artwork lighting.
Original tracks by means of incandescent fittings had high energy consumption and were utilising phased-out technology.
Original lighting fixtures had some degree of optical control.
Lighting regulatorwas done via traditional rotary dimmers from 1996 offering limited flexibility.
Exit and emergency luminaires was inclusive of a single point non addressable system with separate batteries. Fittings were obtrusive, large and not as much as efficient than newer technology.
Security lighting was through separate fluorescent battens with no optical control.
Surface fixed conduits to other services such as smoke detectors were showing and obtrusive.
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Objectives of the refurbishment: •
Increase the gallery’s performance in terms of sustainability, maintainability and protection;
•
Provide lighting to enhance art viewing conditions with consideration to conservation and photo-degradation needs;
•
Reduce glare and discomfort;
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Arrange for a lighting solution that features intelligence and flexibility that is also in line with the original architectural fabric;
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Provide a lighting system that attains energy savings through effective luminaires and intelligent control;
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Reduce maintenance costs.
Lighting Solution Gallery Lighting Every lighting track was replaced by a new DALI lighting track. In the traditional gallery spaces, the track was buried in the plasterboard for a more seamless aesthetic. Track locations were revised to provide ideal offset from the gallery walls. Although this resulted in better lengths of track than the previous installation, the luminaires can be located where they are desirable to provide a seamless lighting scheme. This offset also decreases glare from the light source on the artwork glass, providing a more ideal location,
DALI lighting track
improving the viewer experience.
All current surface mounted conduits were repositioned within walls for a cleaner visual surroundin. BB The original vertical tracks were also improved, however the visual intent stayed in line with the original design. New LED fittings replaced earlier incandescent fittings for over-all circulation and artwork lighting, and were planned accordingly. Glare shields were added to fittings where compulsory for visual comfort.
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Exit and Emergency Lighting New LED emergency and exit luminaires were provided, affecting in not only an energy benefit, but also a more integrated visual appeal. Where possible, the emergency luminaires were integrated into the base of the vertical tracks to decrease the visual lighting infrastructure and make a streamlined aesthetic. The new fittings were also provided along with long-life lithium batteries for better longevity of the installation, and decreased maintenance requirements. Lighting Control System. An intelligent DALI lighting control system was fitted in the gallery to provide flexibility and adaptability of the lighting control system. The gallery has been divided into to three DALI universes with precise gallery spaces assigned to each universe for ease of programming. A control universe refers to a network of fittings that can be controlled by one DALI controller. Each universe, or network, can control a maximum of 64 addresses, though it is advised not to load the network to 100%. Within these universes all luminaires are individually programmable. These levels can be set by the gallery staff with the help of a mobile device/ tablet application. Scenes can be selected through the mobile device/tablet application, The general modes that have been taken consideration include:
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1. Open for Visitors: Artwork lighting luminaires are separately programmable and are set to levels to suit artwork desires. A variety of fittings that face downwards, rather than at the artworks are fixed to a level to offer general circulation lighting. Each time an installation is changed the luminaire settings need to be looked over and adjusted as needed through separately addressing the lights from the mobile device/tablet application. The luminaires that are used for circulation lighting are also used in the mentioned below two settings. 2. After Hours Security: Selected luminaires known for circulation lighting are dimmed to 20% . 3. Working/Cleaning: Selected luminaires known for circulation lighting are dimmed up to 100% for this mode.DALI control system offers adaptability and flexibility for the changing nature of a gallery space. Spare capacity has been in-built into the system as a contingency for future additional luminaires.
3.2 CASE STUDY 2 Yale University Art Gallery collection. With over than 200,000 objects in its care, the Yale University Art Gallery houses hold a vast permanent collection with works alternating in date from ancient times to present day. The collection has grown considerably.. And today, after a $135 million renovation, the gallery now ,has a structure worthy of its holdings. This project also joins a complex array of natural and electric lighting strategies, comprising a significant number of LEDs, to construct a vibrant experience for visitors. Because there is a science to the amount of light an art object can be exposed to over the course of a year to reduce damage, Hefferan helped the staff develop an annual report on light exposure budget for the various gallery spaces where thoughtful artworks may possibly be exposed to light readings above maintenance standards for short durations, but then black-out shades and other similar devices are employed to reduce exposure when the galleries are shut.
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Hefferan had a myriad of electric lighting needs to tackle as well. Some of the galleries required contemporary updates to historical fixtures, while others necessitated that 21st-century lighting systems be installed in 19th-century spaces. But the biggest challenge was determining the type of light source, says Hefferan: “Do we want LED or do we want halogen? There is pressure to move to LED—it’s fashionable for its efficiency and energy cost savings—but in the museum world there is hesitancy. The museum staff has been looking at these objects under halogen their entire life and LED just looks different.”
LEDs were also used in many of the exhibition cases and in special installations, such as for backlighting a 16-foot-tall stained glass window— The Good Knight— by John La Farge. Hefferan worked with the gallery’s carpenters to customize a removable curtain of 54 4200K white LED light panels to go behind the window. “That would not have been possible any other way without making it either incredibly difficult to maintain or without having to provide accommodations for heat buildup,” Yoshimine says.
S ince color temperature preferences vary depending on the show, Hefferan
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designed a system where each curator gets to mix the color to his or her preference via an easy-to-control dimmer system in a nearby closet. Hefferan had some worries. In a gallery setting, the illumination restrictions are low, and at Yale it’s just 5 to 15 footcandles for most of the models displayed. The trick is creating a condition where visitors can adjust to the interior light levels quickly and stay there, or else you can create what Hefferan calls the matinee effect, where a user becomes blinded by the bright light. A stray window or a high-glare track fixture instantaneously jumps you into a high alteration and then the place can look gloomy. Eventually, Hefferan and the museum staff opted for a blended approach, with a combination of 20W MR16 halogen accent lights used to emphasise the art with a 25W LED source for general ambient illumination and wallwashing. Hefferan says he can see a day when a museum could be outfitted in all LEDs, but that the industry still has some work to do. “When I give a presentation on LED lighting used in museums, my subtitle is ‘A Cautionary Tale’ because of the potential for glare,” he says. “From my perspective, we’re going to get there, but it’s OK to move forward in small incremental steps.”
3.3 CASE STUDY 3 Sadie J. Valeri’s instructional art studio, Sanfrancisco.
The studio has north light windows, but in the evenings they light up the studio with artificial daylight bulbs bright enough to be suitable for drawing and painting.
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Overhead Lighting
A lot of research was done before they had installed their overhead lighting, and they were happy with the setup: Strong, white, fullspectrum bulbs that light up the room for their evening classes. They were originally considering Kino Flo bulbs at about $22 per bulb, but after looking at all the options, realized that Philips sells a tube fluorescent that has equally good ratings for $4 per bulb. They required a Colour Rendering Index (CRI) to be higher than 90, and the Philips bulbs were rated 92 CRI. Philips 40-Watt 4 ft. T12 Natural Supreme 5000K Linear Fluorescent Light Bulb The other issue with Kino Flos is the housing fixtures for the bulbs are also very expensive. So instead, they mounted the Philips bulbs on these 6-bulb housings from Home Depot: Lithonia Lighting Industrial 6-Light High Bay Hanging Fixture The specifications say the housings are for T8, 32 watt, but the T12, 40 watt Philips bulbs fit just fine with no heat increase. The lights generate no discernible heat, and no sound at all. The flicker and hum of bad fluorescents is very distracting, so this was really important to them.
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Easel Lighting When more light is needed on an easel they attached a Daylight Easel Lamp from Dick Blick. “It has by far the best designed clamp they had ever seen on a clamp light, and came with an excellent daylight bulb.” Said Valerie, “I recommend these often to students for their home studios.” Matte Black Cinefoil attached with gaff tape helps regulate the light so it does not spill onto the subject.
Lighting the Model Theyneeded a better setup for lighting the models. We have a set of theatreAriifresnel lights from Nowell’s filmmaking days, but those lights are warm in colour, run hot enough to burn a naked hand, and are heavy and prone to tip their stand the second the sandbags are detached. They have the fixtures mounted on a better quality c-stand so they can be mounted on a boom arm for greater flexibility over the model, but the stand they come with would have worked fine too.
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4
DATA ANALYSIS 4.1 From Literature Study • Most Fluorescent lamps do not give enoughcolour rendition, though some believe they are adequate for viewing black and white photography. •
The CRI (Colour rendition index) is a poor indicator of light value and can usually be ignored. It can roughly tell you how close to full white light a lamp gives. 100 is best, lower than 90 is lacking.
•
Spread of Light: It is imperative to have the light spread the right amount. Too narrow and part of the artwork is dark. If you have to pick between too wide or too narrow, slightly too wide should be picked so the frame is just barely lit.
•
Bare or Diffused: Halogen lamps usually have harsh or sharp edges at the restrictions of the light footprint and distracting patterns from the bulb in the center of the light pool. Both of these aspects distract from the artwork. Diffusers can reduce both of these problems. Most modern museums use diffusers on their lights.
•
Light Placement: Lights need to be placed at an angle to the art work, (since at 90 degrees it will reflect right back into your eyes). Usually that means that lights are above the work from the ceiling. Lesser than thirty 30 degrees from directly above the work can distract your eyes by putting too much light on the matt or frame or wall. More than sixty 60 degrees and you begin to see reflections of the light source itself.
•
It is possible to tilt the work a few degrees back at the top so that the reflections are from the top of the opposite walls and the ceiling, but not
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everybody likes this effect and you have to be careful that the ceiling lighting is not reflected. •
Anadvantage of moving to LED is the reduced maintenance costs that are expected, due to the longer life of the LED light source versus a traditional incandescent bulb. This is of particular significance for this installation due to the high mounting location of central vertical track fittings.
4.1.1 From Case study 1 4.1.2 Analysis The Brett Whiteley Studio LED lighting upgrade achieves energy initiatives through application of the following: •
The quantity of luminaires were replaced with the 60W incandescent installations being replaced with 12W LED fittings and the 100W incandescent fittings being replaced with 24W LED fittings.
•
As a comparison of the energy decrease, the total wattage of the previous fittings resulted in a load of 9,880W which was deducted to 2,264W in the lighting upgrade. This produced an energy reduction of 77%.
•
Another advantage of moving to LED is the reduced maintenance costs that are expected, because of the longer life of the LED light source versus a traditional incandescent bulb. This is of particular significance for this installation due to the high mounting location of central vertical track fittings.
•
Improved Light Quality Extensive testing of a range of LED suppliers was commenced to deliver the ideal solution for the gallery space to ensure that the use of LED would surely improve the user experience. The quality of light, installation aesthetic, power consumption, installation size, fitting flexibility and cost were all evaluated. The selected fitting offers a wide range of lenses and wattages within the same family, which was anadvantage for this gallery space.
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Circular fittings were utilised with elliptical beams for over-all wall lighting with a range of spot and flood lenses used where needed. As the lenses are interchangeable, this improves the flexibility and compliance of the gallery lighting arrangement. The LED colour rendering was found satisfactory when compared to the older incandescent fitting with good differentiation between the whites in the paintings. •
Intelligent Programmable Lighting Control and Lighting Optimisation The lighting control in the Brett Whiteley Studio plays avital role in operational savings for electrical intake, in extending the lifetime of the luminaires and in reducing system maintenance. Programming of the intelligent lighting control system allows the setting of lighting control scenes to reduce illuminance levels where likely and conserve energy. Effective aiming of light at dimmed levels is also advantageous from a conservational point of view, reducing the lux hours on the artwork.
4.1.3 Inference • The most imperative thing about properly lighting art spaces is to test a variety of LED lamps in the setting itself. Seeing is believing. When the colour temperatures and beam angles are compared adjacently on the actual art, it usually becomes very clear what looks best. Avoiding the hot spots, glare, and the light that is too white or intense is crucial. Since LEDs appear brighter to our eyes — although the foot-candle readings on the light meter are the same or less — it might take a bit of testing to settle on accurately the right lamps (wattage, lumens, colours, beam angles, etc.) for any given system or instalment. •
Halogen lighting is a popular and reasonable choice when lighting artwork, due to its high CRI. Usually, this helps in allowing artwork to be displayed at its more true state and colour. In addition to its less harmful rays, halogen lighting is a mostly better option than incandescent and fluorescent lighting when it comes to lighting of
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art. Track lighting is popular for lighting art because of its capacity to achieve task and accent lighting with the option of offering energy efficiency through its low voltage counter-part. It can be used to attain quality outcomes when lighting art in a number of locations. Therefore, the grouping halogen track lighting makes it a good choice for artwork lighting. •
Halogen has a minor blue tint and is often too bright. Unnecessary brightness can be reduced by moving the lights farther away from the work, or finding lower wattage halogen bulbs, dimming switches or neutral density filters.
4.2
Case Study 2
4.2.1 Analysis The new LED track fixtures had to offer a solution that was satisfactory in terms of the presentation of the cultural material on display and also in consideration of the preventive conservation necessities of the gallery. The new LED fittings: •
Have a high colour rendering index
•
Are dimmable to suit the specific display requirements
•
Have controlled optics
•
Have interchangeable lenses to place light where needed
•
They created a situation such that visitors can adjust to the interior light levels quickly and stay there, or else you can create what Hefferan (architect) calls the matinee effect, where the user becomes blinded by the bright lights.
•
Has shown animportant energy saving when transitioning from traditional light sources such as incandescent and halogen, to newer LED lighting technology.
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As well as the energy savings, the case studies exhibit that LED technology can improve the light quality of the space and be appropriate for museum and gallery lighting requirements. •
The type of LED improvement is determined by the available funding and condition of the present lighting infrastructure.
•
Energy savings are attainable through a simple LED lamp replacement and upgrade to a more complete luminaire, lighting control and a track upgrade.
•
When LEDs are used with a spot lens, the long-throw distance produces a soft, diffused light that does not over accentuate the surface of paintings
•
The comparative 'coolness' of the light corresponds more closely with filtered natural light. Curators have stated that the
•
light produces a distinguished increase in the sense of space in many paintings and that some darker aspects are more legible at a given lux level. Another positive factor for the curators is that the light does not cause gilded frames to be overly noticeable. LEDs can be dimmed without any obvious drop in the quality of light, so they can be used to gradually increase natural light as required. By contrast, tungsten lighting becomes progressively warmer when dimmed, so within the earlier lighting system they were designed to simply switch on and off according to the need, which proved startling to visitors.
4.2.2 Inferance • Light and heat constitute the utmost potential threats to works of art. Professional LED lighting provides pleasant high-quality light that is mild on materials so it perfectly meets the needs of galleries. In contrast to natural daylight and thermal radiators, light emitting diodes produce low UV radiation and minimal infrared radiation. Other advantages include long lamp life, high energy efficiency and immense flexibility since the light can be easily adapted to individual conditions either optically or electronically.
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•
For works of art to be viewed properly a certain brightness is needed on the surface. Typical illuminance levels in museums is around 50 to 200 lux, depending on the exhibit. New LED technology allows the most sensitive objects to be illuminated now with 70 lux and more, instead of 50, without facing any damage. The light colour is also significant in a gallery setting. At the illuminance levels that are usually used in a museum the preference is for warm white to neutral white light colours (2500 to 4000 Kelvin) because this is the type of light that users find most pleasant. The lighting must also be such that the visitors are not disturbed by glare. Visible light sources or strong points of light in their field of view detract their attention and are considered highly annoying. Usually, an effort is made to adjust the artificial light according to the time of day – from a reddish hue in the morning to a bright daylight around noon and then another reddish hue in the evening. This needs the lighting systems to be equipped with supporting optics and smart electronics. Another important aspect of gallery lighting is the value of the color rendering index (CRI) since the colors of the exhibits must be displayed as naturally as possible.
4.3
Case Study 3
4.3.1 Analysis •
The bulbs need to be elevated above the easel to prevent seeing the reflection in the painting.
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They should be far enough from the easel as not to create a hot-spot on the canvas.
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•
Table lamps or lamps that get clamped on to the easel don’t work very well
•
The Colour Rendering Index should be higher than 90 in an art studio to best perceive colours.
•
LED is a good alternativewhen the flicker and hum of bad fluorescents could be sometimes very distracting
•
The overhead fluorescent tube lighting (Lithonia T8 32Watt) even though expensive, is energy efficient, emits very low heat, minimum flickering and outstanding colour rendering.
•
Finding a solution amid natural lighting, artificial lighting and your budget can be a balancing act, depending upon the subject you are lighting, your style of painting, space you have and funds available.
5
FINDINGS 5.1 •
Lighting in a typical art studio: The main lighting in any art studio should be overhead lighting, whether that be track lighting, recessed lighting, or overhead fixtures. Overhead lighting gives the most evenly distributed light, casting on your supplies, models, and canvas in the same glow. While it may be tempting to choose task lighting, particularly for your canvases, this will result in different lighting profiles between your supplies, models, and
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canvas. Ideal overhead lighting will prevent eyestrain just as well, while keeping things consistent.
•
Once a type of light source is chosen, there are still a number of technical factors that figure into picking lighting for an artist’s studio, including colour temperatures and colour rendering indexes. Colour temperature is measured in Kelvin and is a relative measure that describes the colour of a light compared to a black body radiator at a given temperature. While 6500K is considered to be the purest white light, many artists paint with bulbs close to 5000K, which is less “blue” or cool. This is close to the colour bulb most galleries use.
•
Another critical factor to consider is the colour rendering index of a bulb. Colour rendering indexes run from 0 to 100, and a high number specifies less alteration in the colour. Most artists choose a bulb with a colour rendering index somewhere between 80-100. By bringing together a bulb that reaches all of the right measures, you can ensure that the colours in your art are as true and as vibrant as possible.
•
Colour temperature – Measured in Kelvins or k. 5000K will give you a nice light.
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Brightness - For a medium sized room, a total of 7000 – 8000 lumens is plenty. With a compact fluorescent bulb (not incandescent), that is usually about 110-125Watts.
•
CRI Ratings – The higher the better. Anything over 80 CRI is good.
•
Type – To go with compact fluorescent if budget is medium low.
5.2
Lighting in a typical art gallery
Recommended Light Levels 5 to 10 footcandles (approx. 50 to 100 lux) is presently considered to be the maximum allowable light level for very sensitive materials, such as prints, drawings, watercolors, dyed fabrics, manuscripts, and botanical specimens.
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Up to 15 footcandles (approx. 150 lux) is thought to be appropriate for oil paintings, most photographs, ivory, wood and lacquer objects. Metal, stone, glass, ceramic, and enamel objects are usually thought to be unaffected by strong light. However, heat from lighting fixtures may seriously affect objects, even those that are not susceptible to light damage. Fixtures must allow heat to dissipate through the rear.
5.3
Findings from Visual 2012 software
Room dimensions 3m x 3m
Ambient luminescence CRI 90 7000 Lumens This is the element of light that provides general illumination of the surroundings; it ensures that the immediate surrounding space and its objects and the people there are visible. This form of lighting assists general positioning and activity. Its universal and uniform orientation means that it largely follows along the same lines as measureable lighting design, excluding that ambient luminescence is not the final objective but just the foundation for a more complete lighting design. The aim is not to produce blanket illumination, orone size fits alllighting at the supposed optimal illuminance level, but to have distinguished lighting that builds on the base layer of the ambient light ď&#x201A;ˇ
Floor illumination accentuates objects and pedestrian surfaces. Vertical spatial borders are highlighted by illuminating wall surfaces. Unvarying light distribution emphasises the wall in one piece, whereas accentuating, grazing light gives the wall structure by adding patterns of light. Bright walls create a high level of diffused light in the room.
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CRI 90 7000 Lumens The higher red constituent in warm white light allows rooms to seem warmer than with neutral white light. The higher blue constituent in daylight white light makes a cooler atmosphere. Warm colours of light are favoured above all at lower illuminances and with focussed light, whereas cold colours of light are accepted at high illuminances and diffused illumination. White light is described by specifying the colour temperature, colour rendering, chromaticity location and spectrum. The white colour temperature is divided into three main groups: warm white, neutral white and daylight white. A decent colour rendering with the lighting can only produce a low colour deviation.
The objects and the wall are given a common lighting arrangement by wallwashers. Beams from separateindividual spotlights add emphasis to the objects. A higher brightness contrast increases the level of prominence -When the brightness contrast of the ambient environments to the object is 1:2, a contrast can bearly be noticed. When the ratio is 1:5, a least brightness contrast is established between primary and secondary areas of interest. A contrast of 1:10 brings out the difference thoroughly. A brightness contrast of 1:100 disengages the object very strongly from its ambient surroundings but an unintentional dissection of the wall can arise.
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6 BIBLOGRAPHY 6.1 Lighting: 20th Century Classic by Scala Quin 6.2 NewshamVeich Journal 1998 6.3.http//www.iar.unicamp.br/lab/luz/ld/Arquitetural/diversos/Lighting %20design%20considerations. 6.4. //www.scribd.com/doc/54541780/Light-and-Architecture-MastersThesis#scrib 6.5 CASE STUDT 1http://www.magsq.com.au/_dbase_upl/ACaseStudyonLightingforMuseumsand GalleriesFinal.pdf
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