Lights On Book of Abstracts · SESSION V – LIGHTS AND COMMUNICATION AND MEDIATION P.3 Pedro da...

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This congress joins the international initiatives on the International Year of Light 2015.

HONOUR COMMITTEE

Maria de Fátima Marinho CITCEM, Vice-Rector for External Relations and Culture, University of Porto

Maria João Ramos Vice-Rector for Research and Development, University of Porto

Fernanda Ribeiro Dean, Faculty of Arts and Humanities, University of Porto

Lúcia Rosas CITCEM, President, Dep. of Heritage Studies, Faculty of Arts and Humanities, University of Porto

Carlos Fiolhais Coordinator, National Commission for the International Year of Light, University of Coimbra

Luís Raposo Vice-President, International Council of Museums-Europe

António Ponte CITCEM, Director, Northern Regional Directorate of Culture

John Scott President, New York Conservation Foundation

SCIENTIFIC COMMITTEE ORGANIZING AND EXECUTIVE COMMITTEE

Alice Semedo CITCEM, FLUP Catarina Duarte FLUP

Ana Martins MoMA Cristina Loureiro FLUP

Boris Pretzel V & A Museum Fábio Rabaça FLUP

Carlos Sá CEMUP Giselle Estrela FLUP

Costanza Cucci IFAC-CNR Joana Ramos FLUP

David Saunders The British Museum Leonardo Silva FLUP

David Thickett English Heritage Lídia Azevedo FLUP

Graça Filipe FCSH, UNL Luís Monteiro FLUP

Hannelore Roemich Conservation C., NY Univ. Luzia Sousa UP

Jonathan Ashley-Smith Independent Maria José Cunha FLUP

Luís Miguel Bernardo FCUP Marisa Monteiro Science Museum, UP

Marcus Granato MAST Paula Menino Homem CITCEM, FLUP – Chair

Marta Lourenço MUHNAC UL Sofia Reis FLUP

Matija Strlic Inst. Sust. Protection, UCL Soraya Alcalá NY Conserv. Foundation

Paula Menino Homem CITCEM, FLUP Susana Medina FLUP/FEUP Museum

Pedro Casaleiro Science Museum, UC Tiago Ferreira FLUP

1

PROGRAM 2

ORAL PRESENTATIONS 10

POSTER PRESENTATIONS 45

WORKSHOPS 63

SPACE FOR YOUR NOTES 71

INDEX

2

PROGRAM

LAYOUT

19.07.2015

(Sunday)

20.07.2015

(Monday)

21.07.2015

(Tuesday)

22.07.2015

(Wednesday)

08:30 RECEPTION. CHECK IN

P

OST

ER S

ESSI

ON

09:00 OPENING

SESSION

PO

STER

SES

SIO

N

THEMATIC

SESSION

Oral

presentations

09:30 THEMATIC

SESSION

Oral

presentations

10:00

12:30

10:00

12:30

WORKSHOPS

14:30

18:00

SOCIO-

CULTURAL

ACTIVITIES

THEMATIC

SESSION

Oral

presentations

PO

STER

SES

SIO

N

THEMATIC

SESSION

Oral

presentations PO

STER

SES

SIO

N

14:30

17:00

WORKSHOPS

18:30 CLOSING SESSION

19:30 SOCIO-CULTURAL

ACTIVITIES

21:30 SOCIO-CULTURAL

ACTIVITIES

3

THEMATIC SESSIONS – PRESENTATIONS | ORAL

20.07.15 | ROOM: ANFITEATRO NOBRE (GROUND FLOOR)

08:30 Reception. Check In

09:00 Opening Session

SESSION I - SCIENCE OF VISION. THE PERCEPTION OF COLOUR AS A FUNCTION OF

ILLUMINATION

MODERATOR: John Scott

09:30 Luís Miguel Bernardo Physical Principles on the Illumination of

Displayed Museum Objects

10:00 Sérgio MC Nascimento, Osamu

Masuda

Experiments to Determine the Best

Lighting for Appreciation of Artistic

Paintings

10:15 Miguel Neiva ColorADD, Color is for All

10:30 Questions & Answers. Debate

10:45 Coffee break

SESSION II – BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS

AND TRADITIONS

MODERATOR: Gonçalo Byrne

11:00 João Pernão Light and Colour in the Built Environment

11:40 Helena Câmara Lacé Brandão,

Fernanda Ferreira Bressane,

Gabriella Teixeira Carneiro,

Andredza Gagliano Vieira

Lighting System of Rui Barbosa Residence:

The Artificial Light History Present in

Historic House Museums


12:30 Lunch break

4

SESSION III – BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS

AND DEVELOPMENTS

MODERATOR: David Thickett

14:30

Rob van Beek Electric Light in Historic Interiors with

Particular Reference to the Outphasing of

Incandescent Light Sources

15:00 Jan van Loon, Allard de Graaf Technological Breakthrough in Electrical

Candle Lighting

15:15 Mario Gsellmann Soraa’s GaN-on-GaN Technology LED

Lamps Used in Museums


16:00 Coffee break

SESSION IV – BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS

AND SUSTAINABILITY

MODERATOR: João Pernão

16:15 Boris Pretzel Sustainable Lighting in Museums

16:45 Arlindo Leite, Celso Mesquita,

Isabel Fernandes

Paço dos Duques de Bragança: Improving

the Lighting System to Reduce Costs

17:00 Gonçalo Byrne Natural Light and Artificial Light at the

National Museum Machado de Castro

17:15 Banu Manav, Handan Güzelci Transparency-Light and Time at Museums


5

21.07.15 | ROOM: ANFITEATRO NOBRE (GROUND FLOOR)

SESSION V – LIGHTS AND COMMUNICATION AND MEDIATION

MODERATOR: Matija Strlič

09:00 Guillaume Galloy Rijksmuseum and Boerhaave: Lighting Old

Masters and Innovating with Light

09:30 Suzana Faro Communicate. Museu dos Transportes e

Comunicações, Alfândega – Porto

09:45 José Nuno Sampaio Lights on… Public Place


10:30 Coffee break

SESSION VI – HERITAGE AND LIGHTS. INTERACTIONS FOR CHARACTERIZATION AND

PERCEPTION

MODERATOR: Jonathan Ashley-Smith

10:45 Tiago Dias, Catarina Miguel, Elsa

Murta, Cristina Dias, Vítor Serrão

Fade In, Fade Out. Light Induced Colour

Changes on Varnishes Over Silvered

Surfaces Reproduced From Historical

Recipes

11:00 Tomasz Łojewski, Damian

Chlebda, Witold Zawadzki

Assessment of Spectral Changes of Inks by

Hyperspectral Imaging

11:15 Lee Drake

Qualitative & Quantitative: The Many Faces of XRF

11:30 Jens Stenger, Narayan Khandekar, Ramesh Raskar, Ankit Mohan, Santiago Cuellar, Rudolph Gschwind

Non-invasive Color Restoration of Mark

Rothko's Harvard Murals Using Light from a

Digital Projector


12:30 Lunch break

6

SESSION VII – HERITAGE AND LIGHTS. INTERACTIONS FOR DOCUMENTATION AND

PERCEPTION

MODERATOR: Jens Stenger

14:30 Matija Strlič The Heisenberg Principle of Heritage

15:00 Hendrik Hameeuw, Vanessa

Boschloos, Luc Delvaux, Marc

Proesmans, Bruno Vandermeulen,

Athena Van der Perre

The Combined Use of IR, UV and 3D-Imaging

for the Conservation and Study of Small

Decorated and Inscribed Artefacts

15:15 Ricardo Marroquim, Daniel

Coutinho, Marcus Granato

Digitizing 3D Historical Scientific

Instruments With Laser and Photographic

Technologies

15:30 Natalie Brown, Carolien Coon,

Nanette Kissi, Daniel Garside, Yun

Liu, Lucie Fusade, Scott Allan Orr,

Elisabeth Keats Webb

Public Perception of the Interaction

Between Light and Heritage Objects


16:15 Coffee break

SESSION VIII – INTEGRATED RISK MANAGEMENT. PREVENTIVE CONSERVATION

MODERATOR: Paula Menino Homem

16:30 Jonathan Ashley-Smith Risk Management: Fashion and

Uncertainty

17:00 Christel Pesme, Renée Riedler Using LED Light Source and Microfader: Exploring How it Can Help Improving Implementing Lighting Policy

17:15 Anna Starkey Lightening the Levels - Controlling Daylight

in Challenging Spaces

17:30 David Thickett Managing Natural Light in Historic

Properties


18:00 Closing Session

7

THEMATIC SESSIONS – PRESENTATIONS | POSTER

20 - 21.07.15 | ROOM: HALL NEXT TO ANFITEATRO NOBRE (GROUND FLOOR)

SESSION I - SCIENCE OF VISION. THE PERCEPTION OF COLOUR AS A FUNCTION OF

ILLUMINATION

P.1 Marisa Monteiro,

Maria João Carvalhal

Ophthalmic Instruments in a Museum of Science

SESSION II – BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS

AND TRADITIONS

P.2 Graça Silva Electro-Ceramics Candal, V.N. Gaia. The Production of

Electrical Apparatus

SESSION V – LIGHTS AND COMMUNICATION AND MEDIATION

P.3 Pedro da Silva Using 3D Models in Museums - The Potential Case of

"Castro de Romariz 3D" Project

P.4 Donato Maniello

Michelangelo's David: An Augmented Reality

Application on Real Scale, Using the Technique of

Video Mapping

SESSION VI – HERITAGE AND LIGHTS. INTERACTIONS FOR CHARACTERIZATION AND

PERCEPTION

P.5 Alfredo Araújo, Simão

Morgado, César Oliveira

Lights On – Chromatographic Analysis on Roman

Open Lamps

P.6 Marco Afonso, César

Oliveira, Paula Menino

Homem, Alfredo Araújo

Research on the Ceramic Lamps of the Natural

History Museum Egyptian Collection, University of

Porto

P.7 Natalie Brown, Tom

Fearn, Dirk Lichtblau,

Matija Strlič

Non-destructive Material Characterisation of

Chinese Paper using Near Infrared Spectroscopy

8

P.8 Yun Liu, Matija Strlič, Dirk

Andreas Lichtblau, Nancy

Bell, Konstantinos

Ntanos, Robert J.

Koestler, John Mitchell

Dose-response Function for Paper Containing Iron

Gall Inks

SESSION VII – HERITAGE AND LIGHTS. INTERACTIONS FOR DOCUMENTATION AND

PERCEPTION

P.9 Alia Vázquez Martínez,

Benito Vilas Estevez,

Miguel Carrero Pazos,

Eleni Kotoula

New Techniques for Rock Art Recording:

Comparative Analysis of Radiance Scaling and Virtual

RTI

P.10 Elisabeth Keats Webb Three-dimensional & Infrared Imaging for Object

Documentation

P.11 Tomasz Łojewski, Łukasz

Lasyk

Automatic Reading of Documents with a New Type

of a Multispectral Scanner

SESSION VIII – INTEGRATED RISK MANAGEMENT. PREVENTIVE CONSERVATION

P.12 Rita de Cássia Doria Ultraviolet Irradiation on Coverage Woods for

Biodeterioration Control: Contribution to the

Preservation of Historic Buildings

9

WORKSHOPS

22.07.15 |

REF. ROOM AUTHOR(S) TITLE

W.1 FLUP | Sala de Reuniões

2nd Floor

Hendrik

Hameeuw

Multi-light Reflectance

Technologies: The RTI and PS

Techniques for Museum

Collections and Field Work

W.2 FLUP | LabCR

4th Floor

Giancarlo

Parma

Workshop for Conservation:

Microscopy and Documentation

2D/3D Measurements for Surface

Characterization

W.3 CEMUP

http://www.cemup.up.pt

Carlos Sá On the Application of X-rays for

Research and Characterization of

Cultural Heritage Objects /

Materials

W.4 FLUP | Room 201

2nd Floor

Lee Drake X-ray Fluorescence: Principles

and Practice

W.5 FLUP | Room 203

2nd Floor

Romantic Museum

www.cm-porto.pt

David Thickett

Boris Pretzel

Using Natural Light in Historic Properties

W.6 FLUP | Room 202

2nd Floor

Jacob Thomas

Tomasz

Łojewski

Microfading Testing: A Tool for

Informed Policy Development

and Materials Testing

10

SESSION I - SCIENCE OF VISION. THE PERCEPTION OF COLOUR AS A FUNCTION OF ILLUMINATION

MODERATOR: John Scott

ORAL PRESENTATIONS

11

INVITED SPEAKER

Physical Principles on the Illumination of Displayed Museum

Objects Luís Miguel Bernardo1 1 Physics and Astronomy Department, Faculty of Sciences, University of Porto, PT

Corresponding author: [email protected]

Abstract: The illumination of displayed museum objects must fulfil basic requirements such as the established conservation rules, aesthetic values and the visitors’ viewing expectations. Therefore, choosing the right intensity and spectral colours of those objects’ illumination is most frequently a very demanding task to curators, light designers and engineers. For a correct decision, the basic principles of white light composition, light interaction with the materials, measurements of the intensity and colours, and human visual perception must necessarily be considered. The spectral analysis and synthesis of white light are particularly relevant to understand the objects’ physical colours. The use of a particular spectral composition may be constrained by conservation restrictions and the public aesthetic and visual expectations. Alternative choices must, therefore, be considered to overcome possible incompatibilities. Radiometric and colorimetric measurements must be considered to characterize the illumination conditions and establish the best set-up. The physical observation conditions must be evaluated through the knowledge of the reflection, transmittance, absorption and scattering phenomena, affecting colours and intensities. Finally, the physiological effects of a particular illumination on the human vision have to be evaluated, under the principles of photometry and human vision physiology. All these ideas and concepts will be presented and discussed considering the particular restrictions imposed by the museum objects and the public viewing expectations. In this context, the importance of the light spectral composition and the radiometric and photometric characterization of the illumination will be particularly stressed. Keywords: Illumination; Intensity; Colour; Radiometry; Photometry

12

Experiments to Determine the Best Lighting for Appreciation of

Artistic Paintings

Sérgio MC Nascimento1, Osamu Masuda2 1 Centro de Física, Universidade do Minho, PT 2 The Norwegian Colour and Visual Computing Lab., DCST, Gjøvik University College, NO


Abstract: In empirical studies based on accurate monitor simulations of a set of artistic paintings (Pinto et al, Journal of the Optical Society of America A, 25 (3), 623-630) it was found that the correlated colour temperature (CCT) preferred by a large pool of observers was on average around 5100 K. The goal of the present study was to determine the best illumination but using real paintings illuminated by real light sources. A spectrally tuneable light source based on the Digital Light Processor (DLP) technology (OL 490 Agile Light Source, Gooch & Housego) was used to generate the illumination, with an illuminance of about 200 lux. The spectral composition of the light source could be tuned very fast with a spectral resolution of 20 nm using in-house software. The illuminants were daylights synthesized from Judd’s daylight spectral basis functions with correlated colour temperatures (CCT) ranging 3,600 – 20,000 K. Seven observers performed the experiments. The task of the observers was in each trial to adjust the CCT of daylight to produce the more pleasant appearance of the paintings. For comparison, the same paintings were simulated on a calibrated colour monitor from hyperspectral imaging data and a mirror experiment with simulated images was carried out by the same observers. It was found that the CCT preferred by observers varied with the content of the painting, but the average CCT for real and monitor viewing conditions were very similar, 5500 and 5700 K, respectively. These results confirm that CCT for best appreciation of paintings is higher than normally used in museums, and the viewing conditions, real or simulated, have only a minor effect. Keywords: Illumination; Colour Vision; Colour Rendering

13

ColorADD, Color is for All Miguel Neiva1, 2 1 Miguel Neiva Design Studio, PT 2 Ashoka Fellow


Abstract: In most countries colorblindness affects 10% of the male population. It is estimated that 350 million people in the world are colorblind! This handicap incurs limitations as well as uncomfortable personal and social situations for those afflicted that depend on others to choose products in which color is a predominant factor, such as pieces of apparel, decoration, traffic, recycling, identifying specific rooms in museums and other public spaces when color is the relevant element for choosing. A sample group of colorblind people questioned in a study found relevant the development of a system which would allow them to identify colors. The development of a graphic color identification system was the answer to this need, its concept and structure making it universal, easy to communicate and memorize - a unique, universal, inclusive and non-discriminative language that enables the colorblind to identify colors, with a wide infinite spectrum of usage whenever color is a factor of identification, orientation, fruition or choice. This system can be applied to a variety of products and allow the colorblind to reduce or even eliminate their dependence on others. ColorADD was born for all, allowing full integration whilst keeping the privacy of colorblind - including without discriminating. It creates added economic and social value to companies or entities that use the code, by offering to their consumers an innovative product with a strong social footprint. Also Culture is a strategic sector of our mission and consequently it is one of our primary concerns. At several national museums, ColorADD is already adopted not only as part of the museums themselves but also several activities are already developed to allow public to become acquainted with this code, thus providing another acquisitive tool of universal and transversal utility. Our target is to take color to all! Keywords: Colorblind; Culture; Museums; Design for All; Inclusion

14

SESSION II - BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS AND

TRADITIONS

MODERATOR: Gonçalo Byrne

15

INVITED SPEAKER

Light and Colour in the Built Environment João Pernão1, 2

1 CIAUD-Centro de Investigação em Arquitetura, Urbanismo e Design, FAUL, PT 2 APCor-Associação Portuguesa da Cor, PT


Abstract: In the Book of Genesis there is a dramatic change in the world when God says: Fiat Lux (Let there be light)! Chaos was ended. In our everyday life when we hear a noise while asleep at night, we are afraid because there is no light, and if there is no light we don’t see anything, i.e., we don’t know. When we turn on the light everything around us gets organized: light ends the chaos of darkness. In fact we rely more than 80% on our sight sense to bring us what is happening around us. To see is to know, don’t you see? Light is the genesis of visual perception, and colour is its vehicle. We understand the world around us by the organization of colour stimuli received by our eyes, transmitted to our brain and interpreted there. We can say that colour is the form of space because it is through colour that we perceive the limits and the forms of our environment. Therefore colour should be studied, together with light, its origin, as the main actor in space perception, and therefore in architecture. With these assumptions in mind we have to distinguish between Inherent Colour and Perceived Colour. The first is the colour of the surfaces, which could be read by a colorimeter, without the interference of the human perception or the outside lighting conditions. The second is the colour perceived by the human being, always different according to three variables: light, the observer and the surface. If any of these variables change, the perception will be different: if the light changes its position, or its characteristics, if the observer moves to another place or looks in a different direction, if the surface is placed under or above the observer, or with a different angle, etc. Our work as Color Consultants proves that the knowledge of this continuous variation in colour perception is a tool that we can use, rather than a disadvantage, to design better spaces for human life and comfort. Keywords: Light; Colour; Built Environment

16

Lighting System of Rui Barbosa Residence: The Artificial Light

History Present in Historic House Museums Helena Câmara Lacé Brandão1, 2, Fernanda Ferreira Bressane1, 2, Gabriella Teixeira Carneiro1, 2, Andredza Gagliano Vieira1, 2 1 Fine Arts School of Federal University of Rio de Janeiro, BR 2 Rui Barbosa House Foundation, BR


Abstract: This paper presents the active lighting cataloging of Rui Barbosa House Museum, located in the city of Rio de Janeiro, Brazil, in order to record the history of electricity in the Brazilian habitations. The illumination of spaces is not only to allow visual perception, it means, the view or the viewing of the room. The light from the lighting equipment is part of the ambiance of the room. It promotes, together with the coatings, furniture and other decorations, specific light stimuli that are part of the decorative art of a time and documents the way of life, the uses and customs of a society. For this reason, the lighting of a room should be registered and preserved during the process of turning the house into a historic museum. The methodology used for this purpose was the field research for the collection and data record about the house museum illumination. This research made use of the physical and photographic survey of points of light, as well as building materials, furniture and decoration equipment. The points of light correspond to primary sources of light. The construction materials, furniture and decoration equipment are reflective surfaces that behave as secondary light sources. Together, those sources generate the lighting environment, and therefore, need to be catalogued. This activity resulted in the preparation of catalog cards for documentation and in the conclusion that, sometimes, the demand for new uses requires building facilities to adapt to the reality of their time, making harder the preservation of data. This conclusion was obtained from realizing, that many of the facilities didn’t meet the original characteristics and this occurred due to demand from current activities. It raises the discussion of the viability of artificial light history present in historic house museum, which is directly connected to the safeguard of heritage.

Keywords: Electricity; Artificial Lighting; House Museum; Safeguard; Heritage

17

SESSION III - BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS AND

DEVELOPMENTS

MODERATOR: David Thickett

18

Electric Light in Historic Interiors with Particular Reference to

the Outphasing of Incandescent Light Sources Rob van Beek1 1 Central Government Real Estate Agency, NL


Abstract: The incandescent lamp has had its day. As a result of new European regulations, the gradual abolition of incandescent lamps began in 2009. Most standard incandescent lamps are already no longer available and the last lamp scheduled to disappear in 2016 is the halogen lamp. Monumental buildings often feature historic, and in some cases authentic light fittings, using incandescent lamps as the source of light. These light fittings are historically valuable, they form an intrinsic part of a space and their illumination is indispensable to the character of that particular space. The purpose of this study is to investigate the usability of the alternatives for the incandescent bulb offered by the lighting industry. We tried to make an inventory of the products available and tested many of them. The different light sources were visually evaluated in historic settings by architects, curators and others involved in maintaining historic interiors. Besides, some products were, on our request, technically tested by independent laboratories. Over the last years our project became more international. We shared our findings (among others) with ARRE, the Network of European Royal Residences. We started a dialogue with the international lighting industry to make clear to them what we are looking for and to get familiar with their development plans for the near future. Conclusions so far.

- In our opinion there is, at the moment, no all-purpose suitable LED light alternative for the incandescent bulb available. - LED products are getting better but will probably never get the same quality of light as an incandescent light source. - LED techniques are offering new possibilities to lit up historic interiors in a new way. - The information given by producers of light sources that comes standard with their products isn’t sufficient to know what kind of light one is buying.

Keywords: Usability of Replacements for Incandescent Light Sources; Lighting in Dutch Royal Palaces; Quality and Development of LED Light Sources

19

Technological Breakthrough in Electrical Candle Lighting Jan van Loon1, Allard de Graaf1 1 EVA Optic BV, NL


Abstract: Over the past decades many candles in historical chandeliers have been replaced by

electrical solutions for safety and practical reasons. It has been a challenge to find a suitable

alternative for the traditional candle or traditional light bulb which meets modern-day needs

while keeping the historical and aesthetic value. In light of the EU Directive for phasing out inefficient light sources including Halogen (2018), the need for high quality alternatives has become urgent. EVA Optic, specialist developer of LED lighting for demanding applications, has performed extensive research to determine the crucial qualities of lighting in historical interiors and how LED technology can answer to the urgent need of finding a suitable, high quality alternative in historic candle lighting. This has resulted in a technological breakthrough in electrical candle lighting. EVA LED Candle is the first LED candle that truly helps restore the authentic atmosphere of historic buildings to their origin. Test results of an independent research commissioned by the Central Government Real Estate Agency in The Netherlands show that the desired light quality levels for historic interiors can be achieved with this particular LED candle. Now that it is technically possible to successfully use LED technology in historic buildings while maintaining the authentic atmosphere, it opens endless possibilities. What are the learnings regarding LED applications in historic buildings? What light characteristics are determinative for maintaining the authentic atmosphere of a historical setting? What are the advantages and possibilities of LED technology? How to define quality in LED? How to determine the right light colour (spectrum, CRI vs. CQS) for a historical interior? Keywords: Candle Lighting; LED Technology; Light Quality; Aesthetic Value; Sustainable Design

20

Soraa’s GaN-on-GaN Technology LED Lamps Used in Museums Mario Gsellmann1 1 SORAA, US


Abstract: In SORAA, the developments is based on GaN-on-GaN technologies. Our principal goal is reach a rendering colors and whites as halogen light source. On opposite way of blue-pumped LED with a color rendering index of 85 (BLED85), in SORAA we use High Light Extraction efficiency in bulk-GaN based volumetric violet LED with a color rendering index of 97 (VLED97) using full spectrum-emission. Moreover, for the question: -Should color and whiteness rendition be sacrificed to archive higher efficacy? We focus on a folded-prism optic, reducing contact and junction resistance by controlling the LED’s forward voltage. In conclusion, the light source nearest to halogen, where the light came from a point-source LED (i.e, that can be focused in a narrow and highly controlled beam), also without change MR16 (QR-CB) dimensions, neither compromise colors and whiteness rendition or luminous efficacy is what we intend to show. Keywords: SORAA; GaN-on-GaN

21

SESSION IV - BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS AND

SUSTAINABILITY

MODERATOR: João Pernão

22

Sustainable Lighting in Museums Boris Pretzel1 1 Victoria & Albert Museum, UK


Abstract: Sustainability is defined as the ability to continue a defined behaviour indefinitely. Often raised in relation to “global warming”, or “climate change”, it brings up discussion of “carbon footprints”, “renewable energy”, “green technologies”, etc. In a museum context, sustainability can be extended to collections: how they are treated, stored and displayed, and the balance chosen between accessibility and preservation. Museums have existed since the 18th-century (or before - depending on how narrow a definition of “museum” is used). Early museums depended solely on incident daylight for illumination. Evening opening, together with the use of artificial illumination, were ideas first pioneered by the V&A in the mid 19th-century. Using artificially illumination to display museum collections was highly controversial when first proposed. Many colorants were known to be fugitive and lightfastness was a topic documented already in the 16th Century. There was a real fear that artificial light would increase fading, putting collections at unacceptable. Comprehensive studies on the effects of different regions of daylight on pigments were therefore conducted from the late 19th-century, concluding that, in general, artificial illuminants were less damaging than daylight. In the period that followed, more and more daylight was excluded from galleries, with increasing reliance on artificial lighting. As technology evolved – from gas to tungsten to fluorescent to halogen and metal halide, the choice of light source was initially governed by qualities of the light source. By the late 20th century, however, with increasing energy costs and diminishing public funding, the emphasis on cost and efficacy had come to the fore. This talk present some ways that new technologies, in particular LEDs, together with developments in our understanding of the human visual system, can be used to reduce exposure, improve efficiency, and create ever more arresting and effective displays in museums.

Keywords: Fading; Illumination; LED; Sustainability

23

Paço dos Duques de Bragança: Improving the Lighting System

to Reduce Costs Arlindo Leite1, Celso Mesquita1, Isabel Fernandes1 1 Paço dos Duques de Bragança – DRCN, PT


Abstract: Energy costs are increasingly becoming a huge budgeting burden on Portuguese Museums and Monuments. The Ducal Palace of the Dukes of Bragança is no exception. The Monument is open to the public 361 days per year, 9 hours per day and the Museum area is permanently lit to receive around 260, 000 visitors per year (data from 2014). Considering that the Ducal Palace was originally envisioned to display the living spaces of a Noble house, there are rooms with good natural light but in others it is practically non-existent. The illumination of the Exhibits is installed in the ceiling using replicas of brass and iron chandeliers that hold glass cups where lamp bulbs are hidden in order to replicate the assumed mode of lighting used in the original 15th Century Palace design. In the thirteen chambers of the Permanent Exhibition (about 1,531 m2) there are 22 chandeliers that carry 865 lamp bulbs. However, only 450 of these are in permanent use, consuming approximately 4950 W/h. During 2015 the Palace has, as one of its main goals, the reduction of electricity costs and the improvement of the aesthetic quality of the permanent lighting in the Museum. This Lecture is intended to present this on-going project, resorting to the example of our Banqueting Hall where the existing lamp bulbs were replaced by LED bulbs which allowed us to cut the consumption from 1320Wh to 420Wh, a reduction of approximately 69%. Keywords: LED; Energy Efficiency; Banqueting Hall

24

Natural Light and Artificial Light at the National Museum

Machado de Castro Gonçalo Byrne1 1 Gonçalo Byrne Arquitectos, Lda, PT


Abstract: National Museum Machado de Castro in Coimbra stands on a built complex that

stratifies almost two thousand years of age. In a way, it’s condensing the long architectural

history of the surrounding urban settlement. In its fragmented condition it testifies various

heritage layers with its almost criptoporticum (from 60,s BC) through Arab, Middle Age,

Renaissance, Baroque, to some late century fragments.

On recently finished museum, light control and design was a major issue in respect, firstly,

to the architectonic complex balance between heritage, understood as a succession of

several contemporaneities, and our’s own contemporary intervention for the museum,

and secondarily, for the sake of the best museology of the diversified exhibited contents.

Natural light plays a major role for the architectural presence in order to enhance its

magnificent presence along sequential time nuances. Only natural light can introduce time

dimension in architecture, through its continuously contrasting interplay between light

shade that reflects along the unpredictable and almost changing weather and light

character that passion time is printing architectonic forms and spaces influencing its

apprehension and interpretation.

Of course artificial lightning technology is essential to correct and compensate some

insufficient conditions of natural light and ultimately to the major role on displaying the

sometimes delicate balance between conservation and enhancing the visual exhibit

condition.

Between the prominent light artefact of central courtyard framing the sky and panoramic

cityscape and the darkness of the roman cryptoporticus, the new museum creates a new

settlement of intermediary (either natural and artificial) are reacting to architectural

spaces together with exhibition issues continuously balancing conservation and excellent

visual and environmental conditions.

Keywords: Architectural Heritage; Natural Light; Time Dimension; Artificial Light; Exhibition Atmosphere

25

Transparency-Light and Time at Museums Banu Manav1, Handan Güzelci1 1 Istanbul Kültür University, TR


Abstract: Museums do not have to be mysterious shadowy places, where visitors could

observe and feel the history in the dark. On the contrary, experiencing transparency and

existence of light are two important design features in revealing collections and

exhibitions.

At lighting standards published by CIE and/or IESNA, it is well known that art pieces shall

be prevented from direct sunlight, and lighting equipment shall be designed in respect to

the collections. Basic lighting rules related to the light source (such as colour rendering,

colour temperature, efficiency) and lighting system (such as dynamic lighting, pendant

lamp hanging, and movable lighting) and optimum visual comfort parameters shall be

satisfied.

Occasionally, transparency by means of light penetration and/or interior mood is a very

dominant design feature. Within this wider framework, this paper aims to focus on the

concept of “transparency – light and perception of time” at a thematic discussion. Visitors

shall read behind of the transparent surfaces, which is the only layer between the visitor

and the history. In the study, the concept of transparency will be discussed at various

subheadings; transparency at façade and sunlight penetration inside, transparency and the

physical boundaries of exhibition areas together with lighting system. The hierarchy of

spaces; transparent – semi-transparent - translucent surfaces and their effect on space

organization and mood are discussed over museums of the 20th century.

Keywords: Light; Museums; Transparency; Mood

26

SESSION V - LIGHTS AND COMMUNICATION AND MEDIATION

MODERATOR: Matija Strlič

27

Rijksmuseum and Boerhaave: Lighting Old Masters and

Innovating with Light Guillaume Galloy1 1 Philips Lighting, NL


Abstract: If we look back into museums history, most important evolutions have been for a

very long time about giving access to a wider audience. This is the evolution we see from

the Italian Princes private collections back in the XVth century till the public museums in

the 50’s.

More drastic evolutions happened when accessibility became (almost) a given. From

quantitative, the question morphed into qualitative: What is the best way to show? What

is the right environment? How can we provide a better context, a better understanding of

the artefacts we are showing? What is the true meaning? And, on top, came new

necessities: Art preservation, economical sustainability, differentiation in a global

environment…

Museum became multinationals, competing with each other, licencing their names…

Visiting museum became an experience.

As light suppliers, we have been partnering with a couple museums, working along with

them to give life to their vision, to make it tangible.

We will talk through two cases, the Rijksmuseum in Amsterdam that reopened in 2011

after a 12 years long renovation process and the Boerhaave museum that hosted an

exhibition about research at Philips. These two examples draw two very different

directions, one purely about light, aiming at a pure and simple experience, the other one

about what light can do… beyond illumination. We will look at the importance of the

collaboration in order to define the real needs, and fulfil them.

Keywords: Museum; Experience; Collaboration; Innovation

28

Communicate. Museu dos Transportes e Comunicações,

Alfândega – Porto Suzana Faro1 1 Museu dos Transportes e Comunicações, PT


Abstract: The exhibition Communicate is based on an anthropological concept of

Communication and consists of a path that challenges the visitor to experiment and reflect

upon the many forms of communication that Man established to interact with others and with

his surroundings. Light is a central concern, in the exhibition space and in its contents:

• Senses Alert: sight is the perception of the physical surroundings through the light they

emit or reflect.

• Step into the light: interactive project where you use your body, voice and senses as a

means of communication, combine them with technology and make it a single living,

visual and musical instrument.

• The Message: it can take many forms and is omnipresent, especially in today’s

digitised world. The Message acquires meaning in a relationship and requires a code, a

context, a medium. The way in which it spreads and circulates often receives powerful

injunctions of technique, art and creativity. The codes broaden the universe of

communication and facilitate human interaction: ColorADD (for people incapable of

distinguishing colours); Morse (messages transmitted through sound, light or visual

signals); Braille (system of reading and writing through touch for blind people); Sign

Language (communication using hand movements but also facial expression and body

language)...

• Messengers: in 1873, Willoughby Smith discovered that the chemical element

selenium could transform light energy into electric pulses, which meant that images

could be transmitted through an electric current: TV became a powerful medium,

penetrating homes transmitting information, ideas and ideals.

What if we could stop being the viewer for a while and try the “other side” of a television

broadcast? Lights On!

Keywords: Communication; Light; Experience; Senses; Messages

29

Lights on… Public Place José Nuno Sampaio1 1 KTH Stockholm - Architecture and Built Environment (ABE)/STH/EE, SE


Abstract: The heritage of a place is its local inhabitants. A “LIGHTMEETINGPLACE” is an activated space where people meet generating a place by activation. An activity is determinant for the attraction factor and lighting adjusts. Contemporary Porto experiences a visitors’ boom. These people are adventurous and naturally curious. These explorers challenge our borders of what is “visitable” and what is mentally “fenced”. The mobility of the nighttime city challenges preconceived ideas of those o left the city core. Outdoor Urban Public Space Lighting gains a new pertinence considering the potential crowds. The city offers art and the museums show us bother cities. The Image of the City by-night introduces the topic of fear and insecurity. Adequate lighting may determine areas of the city to visit and areas to avoid. Simultaneously one finds dark areas of the city where crowds gather. People tend to get attracted by other people. Resultant from a Mobility Program KTH - FEUP (Engineering) at the Project “Future Cities” Competence Center UP the activation of LIGHTMEETINGPLACES in the city of Porto, the generation of public space near São Bento train station, in collaboration with local architects. By activating architecture invites the cross-fields such as: Technologies, Sensors, Data, Accessibility Wi-fi, Mobilities. The common denominator is Lighting Design. Lighting Design and (another) Architecture collaborate in the version 1 of “Metamorfose”, architecture installation by FAHR021.3 . “Metamorfose” version 1.0 near São Bento Train Station has been designed based on a stage lighting Method making use of only three lamps, with two different color temperatures. The Design Version 2 will open June 12th 2015, resulting from a mediating effort between industry, municipalities, public entities, architects, suggesting that beyond age, when a ruin competes with traditional monuments through contemporary language, another level of nighttime dialogue is possible between pedestrians and the city. Keywords: Human Capital; Pedestrian Embroidery; Lightness; Design; Urban-Beings

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SESSION VI - HERITAGE AND LIGHTS. INTERACTIONS FOR CHARACTERIZATION AND PERCEPTION

MODERATOR: Jonathan Ashley-Smith

31

Fade in, Fade out. Light Induced Colour Changes on Varnishes

Over Silvered Surfaces Reproduced From Historical Recipes Tiago Dias1, Catarina Miguel3, Elsa Murta2, Cristina Dias3, Vítor Serrão1 1 Instituto de História da Arte, Faculdade de Letras da Universidade de Lisboa, PT 2 Laboratório José Figueiredo, Direção-Geral do Património Cultural, PT 3 Laboratório HERCULES, Universidade de Évora, PT Corresponding author: [email protected]

Abstract: The use of gold and silver leaves to cover sculptures and altarpieces encloses a symbolic connotation with the divine, deeply related with their ability to reflect light. Silvering is referred to follow the same processes as gilding, and historical technical treatises further advise on the need of a protective coating to prevent tarnishing [1]. Depending on the coating employed the guilder could use silvered surfaces to accomplish different purposes. The most frequently found are plain silverings, with a clear varnish, and silver leaf gilding, where a gold coloured varnish is used to imitate gold [2]. To better understand the execution and degradation processes of colourless and golden varnishes, described in technical literature, several oak wood mock-ups were prepared and silvered with a multilayered structure (size, ground, bole) following the traditional water gilding method [3]. Selected 17th and 18th centuries clear and golden varnish recipes were reproduced and applied over the silvering. The specimens were then subjected to intense light exposure in a xenon-arc lamp test chamber, and visual alterations were documented at established intervals both with photographic records, under visible and UV light, and with colorimetric readings. Moreover, a set of selected mock-ups was analysed with FTIR-ATR spectroscopy to follow molecular alterations caused by accelerated ageing. As result from the light exposure a clear varnish described by Pacheco (sandarac and spike lavender oil) suffered an intense yellowing, while a golden varnish referred by Orellana (shellac, amber, gamboge, dragon’s blood and saffron in ethanol) faded strongly [4, 5]. These preliminary results indicate that it is possible, given the propitious conditions, to misinterpret between a clear and a golden varnish, thus misreading the artist’s intent. Keywords: Silvering; Silver Leaf Gilding; Varnish; Photodegradation; Colorimetry [1] J.-F. Watin, L’art du peintre, doureur, vernisseur., 2a ed. Paris: Chez Grangé, Imprimeur-Libraire, 1774. [2] L. Á. de la F. Rodríguez, Los metales plateados como policromía (las corladuras): análisis-experimentación y restauración.

Universidad del País Vasco, 1999. [3] N.M. Ferreira-Alves, A arte da talha no Porto na época barroca: artistas e clientela, materiais e técnica. Arquivo Histórico,

Câmara Municipal do Porto, 1989. [4] F. Pacheco, Arte de la pintvra, sv antigvedad, y grandezas, Sevilla: por Simon Faxardo, 1649. p. 410. [5] F. V. Orellana, Tratado de barnices, y charoles. 2ª ed. Valencia: por Joseph Garcia, 1755. p. 14

32

Assessment of Spectral Changes of Inks by Hyperspectral

Imaging Tomasz Łojewski1, Damian Chlebda1, Witold Zawadzki2 1 Faculty of Chemistry, Jagiellonian University in Krakow, PL 2 Faculty of Physics, Jagiellonian University in Krakow, PL Corresponding author: [email protected]

Abstract: Evaluation of changes induced by conservation treatments for paper-based objects encounters difficulties related to the lack of appropriate experimental methods which could be used to track changes in the color of ink lines. Conservators often resort to digital photography or flat-bed scanning to document their work. Quality of data obtained with such equipment, having high special but very low spectral resolution (3 lines – red, green, blue) does not allow to track minute but still visible and thus important changes in the object’s appearance. Hyperspectral imaging offers a quick way to collect spectra with both high special and spectral resolution. Image registration (alignment) for datacubes obtained for a given document before and after the studied treatment may permit for quantitative assessment of changes. The presented work will focus on the use of hyperspectral imaging for quantitative evaluation of documents with modern and historical inks which have been subjected to low-pressure cold-plasma disinfection. Our goal was to obtain results of a single measurement with experimental error well below the value of ∆E= 1 – a threshold color difference for a human eye. Experimental set-up as well as calibration and measurement procedures which allowed achieving the targeted precision will be presented. Plasma disinfection is a new technique that does not require the use of any of biocides, which may endanger the person performing the procedure. Its effects on the paper substrate have been reported in the literature, its effects on dyes present in archival records or works of art - which in a very reactive environment can be adversely changed - was not yet tested. The Project was financed by the National Science Center Poland (decision No. DEC-2011/03/B/HS2/05221). Keywords: Hyperspectral Imaging; Ink

33

Qualitative & Quantitative: The Many Faces of XRF Lee Drake1, 2 1 Bruker, US 2 University of New Mexico, US


Abstract: While the science of X-ray fluorescence (XRF) has been successfully applied in

multiple disciplines for decades, it is only in the past 10-15 years that portable, non-

destructive instruments have become available for use in geology, archaeology, and art

conservation. The use of these instruments, while using the same physical principles of

their laboratory-based predecessors, presents radical changes to the methodology. Often,

in place of prepared and homogenous samples, unprepared samples are measured in a

completely non-destructive way.

While this does not preclude quantitative analysis and sound practice, it does present

unique challenges that must be addressed. In general, three methodologies can be

employed:

1. Quantification: Reference standards can be used to build calibration curves to convert

photon counts to concentrations. While this has been common practice for scientific

instrumentation, nondestructive assays require matrix-specific reference standards

with elemental ranges which capture the expected extremes within the analytes.

2. Qualitative: In many cases, quantification is neither possible nor necessary to answer

research questions. The spectra can be used in these cases, typically with pigment and

mineral identification.

3. Semi-Quantitative: In some cases, quantitative information can be gleamed from heterogeneous samples. These include determining layer thickness, peak ratios, and photon contribution to the spectra. While the units are not presented as concentrations, they can nonetheless by suitable to statistical analysis.

While the methodology employed using non-destructive XRF analysis is determined by the question at hand, it is which always best to begin with qualitative analysis to evaluate the feasibility of preferred methodologies. Keywords: X-Ray Fluorescence; Methodology; Qualitative; Quantitative

34

Non-Invasive Color Restoration of Mark Rothko's Harvard

Murals Using Light from a Digital Projector Jens Stenger1, 2, Narayan Khandekar1, Ramesh Raskar3, Ankit Mohan3, Santiago Cuellar3, Rudolf Gschwind4 1 Straus Center for Conservation, Harvard Art Museums, US 2 now at Institute for the Preservation of Cultural Heritage, Yale University, US 3 MIT Media Lab, Cambridge, US 4 Imaging and Media Lab, University of Basel, CH


Abstract: A group of five paintings on canvas known as Mark Rothko’s Harvard Murals (1962) has changed color due to the presence of a fugitive red pigment (Lithol Red) and excessive exposure to natural light in a room with large windows. This project explores the possibility of recreating the original color appearance by using a digital projector as illumination. Traditional painting restoration would have resulted in a non-reversible treatment due to the matte and unvarnished nature of paint surfaces thus considerably limiting treatment possibilities. Restored Kodak Ektachrome photographs of the paintings in their original state from 1963 served as a reference. With a camera-projector system, a compensation image was calculated – in effect a map of the lost color over several millions of pixels. The compensation image was then aligned and projected onto the original canvas resulting in a restored color appearance. This was repeated for each of the five paintings and the original color appearance was recreated without physically altering the painting and is therefore completely reversible. Overall lighting and architecture play a key role in the treatment of the Mural cycle as an environment. As a result, Mark Rothko’s Harvard Murals, which had lost their unity as one piece of art, can now be viewed and experienced as in 1962. The approach of inpainting with light is compared with considerations of cleaning and inpainting in conventional conservation treatments. Shortcomings and limitations as well as comparisons to other projector based conservation approaches are discussed. In addition, this new tool raises ethical questions about originality and reversibility, about switching the “treatment” on and off in an exhibition, and about the appropriateness in cases when light is part of the subject matter of the art. Keywords: Mark Rothko; Inpainting with Light; Camera Projector System; Augmented Reality

35

SESSION VII - HERITAGE AND LIGHTS. INTERACTIONS FOR DOCUMENTATION AND PERCEPTION

MODERATOR: Jens Stenger

36

INVITED SPEAKER

The Heisenberg Principle of Heritage Matija Strlič1

1Institute for Sustainable Heritage, University College London, UK


Abstract: Light is essentially linked to the heritage experience: humans use sight 60% of the time when communicating with the environment. Unfortunately, in its interaction with matter, light simultaneously transmits and annihilates information – an agonizing Heisenbergian dilemma for any heritage scientist or conservator: it is either possible for an object to exist, or to know everything about it. (One could assume that metadata is the object – but let’s leave metaphysics aside.)

We use the extraordinary power of lasers to intentionally remove unwanted layers of objects, and at the same time we produce art objects using the additive manufacturing method of selective laser sintering. We use light bleaching in conservation and protect objects from light during exhibitions. Light is used to activate self-cleaning coatings for historic surfaces and sometimes it forms the artwork itself. A heritage scientist is required to look beyond the usual science toolkit to examine some of the issues arising from the above apparent dichotomies. To understand the existence value of an object in relation to its instrumental (informational) value, we need to engage the relevant stakeholders who hold these values. Using social science research methods in the context of management of geological collections, metadata about objects has been shown to be potentially more valuable than the object itself [1], sampling is therefore potentially not an issue. With chromogenic prints, the loss of colour was found to be less acceptable if dyes fade selectively [2]. In an examination of the public attitudes towards discolouration of paper-based library and archival objects, it turned out that colour contributes insignificantly to the overall notion of damage [3]. Comments such as “Degradation is a sign of objects having had a good life” were not uncommon.

Heritage science not being quantum physics, it could look to social science methods to shed some light on our predicament.

Keywords: Heritage Science; Decision-Making; Social Science; Public Engagement [1]. J. Robb et al.: Quantitative Assessment of Perceived Value of Geological Collections by ‘Experts’ for Improved Collections Management, Geol. Cur., 9 (2013) 529-543. [2]. A. Fenech et al.: Modelling the Lifetime of Colour Photographs in Arch. Collections, Stud. Conserv., 58 (2013) 107-116. [3]. C. Dillon et al.: Collections demography: stakeholders’ views on the lifetime of collections, Climate for Collections Conference, Munich, 7-9 November 2012, Postprints, J. Ashley-Smith, A. Burmester, M. Eibl (Eds.), Archetype, London, 2013, pp. 45-58.

37

The Combined Use of IR, UV and 3D-Imaging for the

Conservation and Study of Small Decorated and Inscribed

Artefacts Hendrik Hameeuw1, 3, Vanessa Boschloos1, Luc Delvaux1, Marc Proesmans2, Bruno

Vandermeulen³ , Athena Van der Perre1 1 Royal Museums of Art and History, Brussels, BE 2 ESAT, KU Leuven, BE 3 KU Leuven, BE


Abstract: The EES (Egyptian Execration Statuettes) Project aims to create multi-spectral 3D images of a series of fragile Egyptian objects of the Royal Museums of Art and History collection (Brussels) in order to avoid future handling and facilitate their detailed study. The texture/colour values on these 2D+ and 3D models are interactive data based on a recording process with infrared, red, green, blue and ultraviolet light spectra. The main device, a multispectral ‘minidome’ acquisition system, is based on the already existing system of the multi-light Portable Light Dome (PLD). Software tools and enhancement filters have been developed which can deal with the different wavelengths in real-time. They ensure the multi-spectral 3D digitalization and visualization of fragile objects, bearing inscriptions or pigments on ostraca, tablets, papyri, etc.; all preserved on/in clay, wood, stone, parchment, papyrus or paper. This leads to an easy and cost-effective methodology which combines multi-spectral imaging with the actual relief characteristics and properties of the physical object; thanks to the use of the multi-light reflectance approach of the PLD system. In addition, creating a set-up which requires minimal handling but delivers maximal output for research and conservation purposes, must be seen as most welcoming in working with fragile objects. The system presents itself as an easy by scholars to use tool and transportable to any collection or excavation in the field. This project is financed by Belspo Brain-be Pioneer: BR/121/PI/EES. Keywords: Multispectral 3D-imaging; Photometric Stereo; Conservation; Documentation; Ancient Inscriptions

38

Digitizing 3D Historical Scientific Instruments with Laser and

Photographic Technologies Ricardo Marroquim1, Daniel Coutinho1, Marcus Granato2 1 UFRJ – Universidade Federal do Rio de Janeiro, BR 2 MAST – Museu de Astronomia e Ciências Afins, BR


Abstract: The digitization of 3D tangible cultural heritage is becoming a widespread

process. It assists in the creation of physical replicas for preserving the original object, for

conducting studies, precise documentation and enhanced exhibition, among other

purposes. Nevertheless, some objects still present major challenges due to their complex

geometry, difficult access, or materials that are not compliant with most acquisition

technologies.

The Digital Bamberg projected was conducted in collaboration between the Computer

Graphics Lab of UFRJ (Universidade Federal do Rio de Janeiro) and MAST (Museu de Astronomia e Ciências Afins), to digitize a historical meridian circle. One of the main goals was to study how 3D scanning technologies behaved when confronted with important challenges, such as: dark and shiny materials (metallic parts), a mechanical instrument, and of historical value (no physical intervention allowed). The digitization process used a laser scanner for geometry acquisition, and high-resolution photographs for appearance retrieval. Most of the challenges were due to the use of these two light-based technologies. The laser, for example, spreads when hitting a metallic surface introducing a high frequency noise, which results in imprecise geometry. Moreover, removing the light influence when taking photographs to acquire the true surface appearance is another critical issue, mainly due to reflections that are difficult to eliminate completely. In this work we discuss the main light-based challenges confronted during this project, as well as solutions to these issues. In a broader sense, the study of light-material interaction is essential to improve digitization techniques, making them more robust, faster, and accessible. In the more specific scenario, this work sheds light on how to efficiently acquire quality geometric and photographic data of complex metallic mechanical instruments, while at the same time, preserving the integrity of the historical object.

Keywords: Laser Scanners; Digitization; Historical Scientific Instruments

39

Public Perception of the Interaction between Light and Heritage

Objects Natalie Brown1, 2, Carolien Coon2, Nanette Kissi2, Daniel Garside3, Yun Liu1, 2, Lucie

Fusade1, 4, Scott Allan Orr1, 4, E. Keats Webb1, 5, 6 1 EPSRC Centre for Doctoral Training in Science and Engineering in Arts, Heritage and Archaeology, University College London, UK 2 Institute for Sustainable Heritage, University College London, UK 3 Centre for Environmental and Geomatic Engineering, University College London, UK 4 School of Geography and of the Environment, University of Oxford, UK 5 Museum Conservation Institute, Smithsonian Institution, Washington DC, US 6 Cultural Informatics Research Group, School of Computing, Engineering and Mathematics University of Brighton, UK


Abstract: In light, the catch-22 of access and conservation is well embodied: it is essential to appreciate art; however, it also contributes to its degradation. To resolve this, we see public engagement as a key element of research. In this work, the public perception of light and light-induced change was investigated using a participatory approach among stakeholders. A questionnaire survey was carried out to explore how the public perceive change caused by light as damage, the dilemma between appreciation with light and preservation without light, as well as concerns with natural and artificial lighting in museums. The results can provide justification for the thresholds of damage caused by light, which can be further integrated with scientific evidence of light induced degradation of materials to provide a sound basis for collection management. This survey was carried out as part of the celebration of the Year of Light at UCL in collaboration with the Wellcome Trust in London, UK, in May 2015. The staff and students of UCL Institute for Sustainable Heritage (UK) facilitated an innovative public engagement project to investigate the analytical applications of ultraviolet, visible and infrared radiation, to examine art and heritage objects from the viewpoints of science, conservation and art history. As a case study, reflectance transformation imaging and spectral imaging provided accurate documentation of the painting materials and techniques, as well as the preservation state of a Graeco-Roman Hawara portrait (Petrie Museum of Egyptian Archaeology, UCL). The principles of visible and invisible radiation interacting with materials and the potential to use different techniques to reveal hidden information embedded in art works, such as overpainting, restoration interventions, distribution of pigments, were explored through interactive demonstrations, which greatly promoted the awareness of the use of light in heritage science to a broad audience.

Keywords: Heritage Science; Radiations; Public Engagement; Light Induced Damage; Stakeholders’ Perception

40

SESSION VIII - INTEGRATED RISK MANAGEMENT. PREVENTIVE CONSERVATION

MODERATOR: Paula Menino Homem

41

INVITED SPEAKER

Risk Management: Fashion and Uncertainty Jonathan Ashley-Smith1

1Independent consultant, UK


Abstract: Preventive conservation is taught as if it were a systematic and scientific subject. This positive view hides the uncertainties involved and neglects the fact that all fields of management are subject to changing fashion. One sign of being up to date with the latest management fashion is fluent use of appropriate vocabularies. But the introduction of a new phrase does not mean a clearer definition of the appropriate way to think and act. Take ‘integrated risk management’ as an example. The word ‘integrated’, used in museum activities, can mean a variety of things. It can mean that all departments within the organisation are aware and involved. It can mean that all stakeholders are consulted, which for museums means considering the expectations and limitations of the visiting public. Integration can mean accepting that risk management is more than a piecemeal tactical approach to individual threats. The word implies that it is necessary to take a strategic view, maximizing the benefits as well as minimizing the downside. In a specific field such as pest management ‘integrated’ means following all of the necessary steps: setting action thresholds, monitoring and identification of pests, prevention and control. In risk assessment ‘integration’ can mean looking at the interactions between hazards, such as synergies between pollutants. Integration recognises that a solution to one problem may increase risk from other hazards. Lighting in museums and historic houses involves all these meanings of the word ‘integrated’. Although it is easy to teach simple conservation guidelines for lighting it is also easy to overlook the uncertainties in the underlying principles. Moreover, even when all the immediate needs of objects, visitors and budget are taken into account, the lifetime of the solution is limited. No matter how good a gallery display looks now, it will go out of fashion. Keywords: Management; Uncertainty; Integrated Risk Management; Stakeholder; Fashion

42

Using LED Light Source and Microfader: Exploring How it Can

Help Implementing Lighting Policy Christel Pesme 1, Renée Riedler2 1 Independent researcher, Basel, CH 2 Object Conservator at the Weltmuseum, Vienna, AT


Abstract: The museum lighting field has been significantly modified by the recent

introduction of two technologies: LEDs are increasingly used for lighting and microfader allows testing surface light sensitivity. The paper aims to explore to which extent using these new technologies can help improving decision-making methods used to implement a lighting policy for vulnerable collection items. The methodology to set a Preservation Target for lighting policy will be presented: it defines the light exposure conditions, in a given timeframe, under which access to values of the given item is maximized, while value loss induced by its exposure to light is minimized. Access quality to values of the item on display is related to its surface appearance and depends on its lighting conditions. In order to address this aspect, defining a Preferred Surface Rendering(s) of the item on display can be fruitful: it determines the lighting conditions under which item values are considered best presented. Such rendering that could be generated using LED light engine with tunable capacity should be set by curatorial decision and documented. A case-study on two editions of Japanese wood prints from the Weltmuseum Wien collection – one pristine, the other naturally faded due to its past exhibition–will serve to illustrate information obtained with a microfader. Two sensitive aspects of the technique will then be discussed: how to optimize surface sampling of the artwork in order to obtain representative and relevant results? How can data obtained from local testing be interpreted and translated into categories of corresponding value loss? In conclusion, it will be emphasized that Preservation Target provides with the indispensable frame in which using the quantitative data obtained with the microfader. Setting it should result from collaboration between curator, conservator and lighting engineer and allows implementing a budgetable lighting policy, adequate for vulnerable collection items. Keywords: LED; Microfader; Lighting Policy; Light Sensitivity; Surface Rendering

43

Lightening the Levels - Controlling Daylight in Challenging

Spaces Anna Starkey1

1 National Trust for Scotland, UK


Abstract: The National Trust for Scotland (NTS) cares for over fifty properties with historic collections on open display. These properties range from Scottish baronial castles to thatched cottages, but each houses a collection that is susceptible to light damage. For the last forty years the NTS has been investing in light protection measures (roller blinds and ultraviolet absorbing window film). This work has been ad hoc, leaving some properties with little or no protection. To address this problem the NTS has funded ‘Lightening the Levels’: an accelerated project to do in 2 years what would take 20 to improve daylight management across all these properties. This paper will explain the various ways the NTS is managing light across its portfolio, showing the scale and scope of the project. It will focus on the challenges that the more unique properties create such as geographic location, access, Scottish weather and the limitations of working in historic interiors. It will also examine the installation and decision-making behind UV film and blinds in these interesting spaces. It will look at the installation of LED lighting in display areas and the collaborative approach the NTS has taken with other projects. A key aspect of the project is how it plans to engage staff and volunteers with the practical aspects of light management. An important part of this has been the introduction of blind drills, ranging from producing procedures and supporting documentation to the practicalities of getting this used at properties by a mainly volunteer property team. Finding the right combination of protection measures for each property has been very important and there is no ‘one size fits all’ solution. The project is learning as it goes along; increasingly the importance of getting staff and volunteers engaged has been shown to be vital to the success of the project. Keywords: LED; Microfader; Lighting Policy; Light Sensitivity; Surface Rendering

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Managing Natural Light in Historic Properties David Thickett1 1 English Heritage, UK


Abstract: Natural light is an essential feature of many historic interiors and significant views

from rooms often must often be retained. This paper will detail procedures developed to

manage it and also elucidate the negative effect it can have on showcase performance and

solutions.

Light plans have been developed to manage daylight. Monitoring natural daylight is

challenging and blue wool dosimeters have been adopted to monitor light doses in historic

houses. The preparation and measurement of these can significantly affect results and

improved procedures have been developed. Stained glass has some ability to reduce light and UV transmission. Monitoring of three hatchments at Lyddington Bede House indicated that in the position the hatchments, light and UV were sufficiently controlled by the stained glass in the windows. Mesh materials and neutral density films have been used to retain views whilst controlling daylight. Within English Heritage's estate many historic properties now contain showcases. Careful design is required to ensure adequate showcase performance environmentally. In such situations the room environments are frequently far from ideal and showcases are often required to perform significant environmental remediation for safe display of their contents. At St Peters church the surface temperature of archaeological bone displayed in showcases under stained glass windows found to have significant daily increases with predicted damaging decreases in surface RH. Simple geometry can indicate when direct sunlight can fall on showcases, mobile apps can dramatically reduce the time needed for calculations. Daylight even filtered through double blinds can effect some sensitive environmental control equipment. Examples of problems encountered and solutions will be presented. Light can dramatically increase off-gassing from showcase materials. At Apsley House allowing too much daylight onto showcases containing supposedly light insensitive objects chemically degraded the woolen display fabrics dramatically increasing the silver tarnish rate. Keywords: Natural Light; Showcases

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SESSION I - SCIENCE OF VISION. THE PERCEPTION OF COLOUR AS A FUNCTION OF ILLUMINATION

POSTER PRESENTATIONS

46

Ophthalmic Instruments in a Museum of Science Marisa Monteiro1, Maria João Carvalhal1 1 Museu de Ciência da Universidade do Porto, PT


Abstract: Medical studies in Porto began, in an organized fashion, with the creation of the

Medical-Surgical School, in 1836; the attendance of a preparatory course taught at the Polytechnic Academy (1837-1911) was required beforehand, in order to gain access to this school. On February 1911, it was elevated to a Faculty of Medicine. The creation degree listed subjects such as Physics and Chemistry for Biology, each one with a duration of one semester, which were taught in the Physics and Chemistry Laboratories of the Polytechnic Academy (which, in March, would itself become the Faculty of Science of the University of Porto). These subjects would be replaced on July 1914 by the “FQN” course (from Physics, Chemistry, and Natural Sciences), preparatory to the study of Medicine, also to be taught at the Faculty of Science, and contemplating an annual chair of Physics. When the Faculty of Science was established, syllabuses were significantly changed, foreseeing the attendance of free magisterial and demonstration lessons and of mandatory practical lessons. Though there were, in the original building of the Polytechnic Academy, several rooms assigned to the Cabinet – later Laboratory – of Physics, these were devoid of resources for experimental work. This would impose the purchase of instruments for demonstration and practice, particularly for Biological/Medical Physics. In September 1912, the Faculty of Science acquired from the Maison Charrière Collin, based in Paris, a set of instruments for Medical Physics. Among others, they purchased a Landolt’s perimeter (for graphical description of the visual field), a Landolt’s ophthalmoscope (for fundus observation), a Perrin’s artificial eye (for practice with the ophthalmoscope) and a set of ophthalmologic lenses, all of them now in the Museum of Science. We will present some of these instruments, as an initial approach to the study of the physics of vision, and understanding of eye defects and diseases. Keywords: Physics of Vision; Museum; Ophthalmoscope; Landolt’s Perimeter; Artificial Eye

47

SESSION II - BUILT ENVIRONMENT. LIGHTING SYSTEMS. REQUIREMENTS, SOLUTIONS AND

TRADITIONS

48

Electro-Ceramics Candal, V.N. Gaia, the Production of Electrical

Apparatus Graça Silva1 1 Department of Heritage Studies, Faculty of Arts and Humanities, University of Porto, PT


Abstract: The company Electro-Ceramic Candal, founded in 1914 and in operation until the late 1980s, today's business park, Candal Park, SA, was an important ceramic production company of the city of Vila Nova de Gaia (Portugal), either by the diverse number of products it produced, and the electrical apparatus production of high and low voltage, or the role it played nationally, at the height of national electrification, and internationally, with the supply to European cities in the post-World Wars of electric equipment for the reconstruction of their cities. Around 1948, Electro-Ceramics possessed an important laboratory for testing the production of high voltage electrical apparatus and this is well documented. Not so with the production of small electrical porcelain appliance (lamp holders, various switches, ceiling rosettes, junction boxes, components of electrical panels, etc.), which we try to study, as main goal of this research. The lack of written documentation led us to look for other sources of information, including oral information, interviews with a former engineer of the company, and access to non-printed documentation from former directors. We will present some results, although it is a work still in progress, and our goal is to continue this study, deepening better knowledge of this company, yet so little explored. Keywords: Production; Electrical Apparatus; Museology; Industrial Heritage

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SESSION V - LIGHTS AND COMMUNICATION AND MEDIATION

50

Using 3D Models in Museums - The Case of "Castro de Romariz

3D" Project Pedro da Silva1 1 Former Student of Faculty of Arts and Humanities of University of Porto (FLUP), PT


Abstract: The "Castro de Romariz 3D" project was developed during the Master's degree in Archaeology, FLUP, between 2011 and 2013. It includes an architectonic and urbanistic study reconstructing the Romariz Castro through the use of 3D computer generated models. Achieved by means of a computer gaming platform, this technology shows great potential for museums, as the gaming platform can be used by the general public, resulting in a ‘learning by entertainment’ experiment. The Romariz Castro is a proto-historical settlement that was inhabited up until the roman age. Located in Aveiro district, in surroundings of the village of Romariz (Santa Maria da Feira, Portugal) this archaeological site shows the existence of superposition of constructions throughout the ages, demonstrating significant reformulations in local architecture.

Contemporary discussions about the impact of media and technologies in museums tend to take this impact as an opportunity for the museum to reinvent itself and ensure its survival in the twenty-first century. The reconstruction of archaeological sites in 3D and its exhibition in museums fulfils this paradigm that visitors should develop scientific knowledge through interactive experimental activities. Likewise, a gaming platform like the one used in the “Castro de Romariz 3D” project can maximize the physical and real experience of general public by reducing the exceeding amount of the quantitative perception of the historical information and by answering the most common questions in a playful way: how was this site in the past and how did its society organized itself? Is it possible to understand the 'romanization event' by looking at the village's architecture on its final stage? Nevertheless, this gaming technology gives museology a new theoretical light - the impact between the real-world of the present and the virtual-world of the past in museum's visitors. Keywords: Archaeology; Museology; Technologies; 3D Models; Castro de Romariz

51

Michelangelo's David: An Augmented Reality Application on

Real Scale, Using the Technique of Video Mapping Donato Maniello1

1 Academy of Fine Arts, Naples / Studio gloWArp, IT Corresponding author: [email protected]

Abstract: The present work is the result of a research started in the course of “Digital

applications for visual art” coordinated by Donato Maniello teacher in Academy of fine arts

in Naples. To achieve and prove such result, in this project it was used a particular

technique of augmented reality called video mapping with the aim of reevaluating the

replica in scale of the world famous “David” by Michelangelo, sculpture present in the

same building.

The installation (projected the 27th February), entitled “Michelangelo's David”, is the

demonstration of how new technologies can play a fine role for the enhancement of cultural

heritage of a nation it got the patronage of UNESCO that has entitled the 2015, International Year of Light and of the technologies based on light (IYL). Thanks to the art of video mapping the rediscovery of this sculpture has achieved a great result, success based not only on the reevaluation of the work of art but also because such performance touched the soul of the audience leaving them in an ecstatic state. Thanks to the live event a large number of the audience for the first time came to know the existence of this replica work present in the building of the Academy of which they totally ignored the presence. Another aim of the project is that of showing the artistic potentiality of the mix among analogical and digital media and how video mapping could be also considered as an extension of the painting. A reevaluation of cultural heritage through video mapping that is perfect for the standards expected by the law in matter of cultural properties in Italy. The action of reevaluation is not to be considered as an attempt to substitute the peculiar value of the work itself. Part of this project will be show in a website (www.3david.it). Keywords: Cultural Heritage; Augmented Reality; Video Mapping

52

SESSION VI - HERITAGE AND LIGHTS. INTERACTIONS FOR CHARACTERIZATION AND PERCEPTION

53

Lights On – Chromatographic Analysis on Roman Open Lamps Alfredo Araújo1, Simão Morgado2, César Oliveira1 1 Chemistry Centre, Minho University, PT 2 Department of Heritage Studies, Faculty of Arts and Humanities, University of Porto, PT


Abstract: Pottery lamps were frequently used in the antiquity on the illumination. Ancient lamps typically used animal or vegetable fats as fuel, being the type of combustible on use largely depended on the availability. Olive oil was probably the principal fuel employed in the Mediterranean countries, but other oils could also be found, as sesame, nut, fish and castor oils, among several other plant oils. Organic residues are frequently preserved inside the container ceramics structure, providing a means to reach important information on what was the vessels content. The chemical analyses generally proceed by solvent extraction techniques followed by gas chromatography with mass spectrometry to facilitate the identification of individual components. This methodology was applied to the analysis of ceramic fragments from seventeen open lamps from the D. Diogo de Sousa Museum (Braga, Portugal). Being a work in progress, we will present our major conclusions. Keywords: Roman Open Lamps; Illuminants; Chromatography; Organic compounds

54

Research on the Ceramic Lamps of the Natural History Museum

Egyptian Collection, University of Porto Marco Afonso1, César Oliveira2, Paula Menino Homem1, 3, Alfredo Araújo2 1 Department of Heritage Studies, Faculty of Arts and Humanities, University of Porto, PT 2 Chemistry Centre, Minho University, PT 3 CITCEM, PT


Abstract: Ancient oil lamps made of ceramic were used as a means of artificial lighting or

symbolic context, from about 3000 BC until the discovery of electric light in the nineteenth

century. This type of lighting, which used animal or vegetable fats as fuel, accompanied human

civilization for millennia and always had a character of the utmost importance, either by their

utility or its meaning, as a source of an element essential to human life – light.

The 3 ceramic lamps in focus are part of the Egyptian Collection which was donated to the University of Porto in 1927 by the Berlin State Museums, in compensation for the return to Germany of the archaeological collection of artefacts from Mesopotamia that had been seized in Lisbon with the German ship "Cheruskia", at the beginning of the First World War. The site where the lamps were found is unknown. We just know that they were acquired in Fayum oasis, at the end of XIX century, and, later, by the Neues Museum of Berlin. Two lamps fall in the "D-type", with geometric motifs and volutes, and can be dated between centuries I to II AD. The third, included in the "frog-lamp" typology, can be dated between the centuries III to IV AD. When exposed to long wave (380 nm) and short wave (254 nm) UV radiation, one of the "D-type" oil lamps and the "frog-lamp", showed fluorescence and phosphorescence in nozzle and inside. This reaction raised the hypothesis of existence of organic remains. Most probably, of fuel oil. But, what type of oil? What were the eating habits and materials used by people from the context these lamps were found? In order to identify the residues, samples were taken and chromatographic techniques were used. Although still in progress, the main results will be presented. Keywords: Archaeometry; Oil Lamps; Roman Egypt; Chromatography

55

Non-destructive Material Characterisation of Chinese Paper

using Near Infrared Spectroscopy Natalie Brown1, 2, Tom Fearn3, Dirk Lichtblau4, Matija Strlič2 1 EPSRC Centre for Doctoral Training in Science and Engineering in Arts, Heritage and

Archaeology, University College London, UK 2 UCL Institute for Sustainable Heritage, University College London, UK 3 UCL Department of Statistical Science, University College London, UK 4 Lichtblau e.K. Dresden, DE


Abstract: Many institutions across the globe hold large Chinese library and archival collections, however to date there has been no systematic study of the material properties of modern Chinese papers. The material properties of a paper directly affect its permanence, and by understanding the chemical composition, the process of degradation can be significantly slowed down and suitable conservation methods developed. Traditionally, destructive tests have been necessary to establish these properties, however using Near-IR Spectroscopy (NIR), non-destructive characterization is possible.

Building on the body of research where NIR has been used on large collections of Western paper and Islamic paper, material properties such as pH, degree of polymerisation, fibre composition, elemental composition, and mechanical properties, are being determined on a large reference collection of 19th and 20th century (modern) Chinese papers. Using multivariate calibration and classification methods, the analytical data can be compared with the NIR spectral data and quantitative non-destructive methods of material characterization can be developed and applied to unknown Chinese paper collections. It has so far been established that papers from the reference collection do not follow the typical acidity patterns of modern Western paper, which likely leads to higher chemical stability of Chinese paper. Due to the low grammage (mass per unit area) of many Chinese papers, some standard methods of testing require significant adjustments, both in technique and in interpretation. The presentation will discuss the results to date: including pH, degree of polymerization and mechanical testing, as well as the development of NIR applications. Keywords: Heritage Science; Paper Conservation; Chinese Paper; Near-IR Spectroscopy (NIR)

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Dose-response Function for Paper Containing Iron Gall Inks Yun Liu1, Matija Strlič1, Dirk Andreas Lichtblau2, Nancy Bell3, Konstantinos Ntanos3, Robert J. Koestler4, John Mitchell5

1 UCL Institute for Sustainable Heritage, University College London, UK 2 Lichtblau e.K. Dresden, DE 3 The National Archives, UK 4 Museum Conservation Institute, Smithsonian Institution, US 5 Department of Electronic and Electrical Engineering, UCL, London, UK


Abstract: Being the ink of choice for centuries in Western history, the chemical instability of iron gall inks is a major threat to paper-based heritage. Based on extensive studies of accelerated degradation of paper induced by iron gall inks, this research is developing a dose-response function to quantitatively evaluate the synergistic effect of environmental agents of deterioration, such as temperature and relative humidity, and potentially also material properties, such as paper grammage, acidity (pH), iron(II) content and application intensity of ink lines on the degradation rate of paper containing iron gall inks. In the context of the information value of iron-gall ink documents, the modelled dose-response function will be further developed into a damage function. This will support collection management by prioritizing parameters that could be controlled most effectively. As a typical non-destructive technique that has been widely applied to the characterisation of cellulose-based materials, near-infrared spectroscopy (NIR) coupled with multivariate data analysis was used in an epidemiological survey to obtain the values of two of the most important parameters in the modelling process—degree of polymerisation (DP) and pH of ink lines. NIR analysis was performed on a selection of 16th to 20th century iron gall ink documents from the National Archives (UK). This will enable us to explore its suitability for the analysis of ink lines on historical materials by providing precise sampling, typically 2 mm in diameter, fast data acquisition without sample preparation, and good indications of pH and DP with high repeatability and reproducibility. Keywords: NIR Spectroscopy; Multivariate Data Analysis; Dose-Response Function; Iron Gall Ink; Degree of Polymerisation

57

SESSION VII - HERITAGE AND LIGHTS. INTERACTIONS FOR DOCUMENTATION AND PERCEPTION

58

New Techniques for Rock Art Recording: Comparative Analysis

of Radiance Scaling and Virtual RTI Alia Vázquez Martínez1, Benito Vilas Estevez2, Miguel Carrero Pazos1, Eleni Kotoula3

1 University of Santiago de Compostela, ES 2 University of Wales Trinity Saint David, UK 3University of Southampton, UK


Abstract: The aim of this paper is to compare the tracing made at the Bronze Age petroglyph of “Barreira” in Verdoejo (Portugal) (Novoa and Costas 2004) with two different and new methodologies based on photogrammetry. This technique is oriented to reduce the different problems of subjectivity that are present in the old systems of registry, and furthermore it allows studying the rock surface without touching it. These techniques are:

• The Virtual RTI proposed as an alternative to normal RTI method, which is a combination of reflectance transformation techniques with photogrammetry and non-contact digitising. It uses animated virtual domes, leading to a sequence of renderings of the 3D model, processed using the same methods as normal RTIs. The virtual RTI provides an advanced level of interaction with the 3D model and enhanced visualization of the surface topography (Earl, Beale, Martinez and Pagi 2010);

• Radiance Scaling is a shader applied to 3D models, which adjusts reflected light intensities in a way dependent on both surface curvature and material characteristics. As a result, diffuse shading or highlight variations become correlated to surface feature variations, enhancing surface concavities and convexities (Vergne, Pacanowski, Barla, Granier and Schilck 2010).

Keywords: Petroglyphs; Photogrammetry; Virtual RTI; Radiance Scaling

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Three-Dimensional & Infrared Imaging for Object

Documentation Elisabeth Keats Webb1, 2, 3 1 EPSRC Centre for Doctoral Training in Science and Engineering in Arts, Heritage and

Archaeology, University College London, UK 2 Smithsonian’s Museum Conservation Institute, Washington, DC, US 3 Cultural Informatics Research Group, School of Computing, Engineering and Mathematics, University of Brighton, UK

Corresponding author: [email protected]; [email protected]

Abstract: Light and the varying optical properties of materials are important for conservation and research imaging to aid in recording the condition, informing care and treatment, and expanding the understanding of cultural heritage objects. Infrared imaging is one of the routine spectral imaging techniques used for paintings and paper conservation recording the varying reflection, transmission, and absorption of infrared radiation by the materials. However, few studies include infrared imaging for the examination of three-dimensional objects including archaeological, ethnographic, historic, sculptural, decorative, and contemporary arts. Three-dimensional imaging techniques, including photogrammetry and white light scanning, more fully document the surface and shape of three-dimensional objects than a single still image. Building on the ability of infrared radiation to penetrate through some pigment and material layers, the integration of infrared and three-dimensional imaging techniques will offer a new level of documentation of an object’s condition, materials, and manufacture. Infrared imaging of objects increases the visibility of obscured details and inscriptions, aids in differentiating materials, and documents the condition including subsurface cracking. The presentation will include results from an imaging case study at the Freud Museum and methods for combining infrared and three-dimensional image data supporting research and conservation documentation. Keywords: 3D Imaging; Infrared Imaging; Photogrammetry; White Light Scanning

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Automatic Reading of Documents with a New Type of

Multispectral Scanner Tomasz Łojewski1, Łukasz Lasyk2 1 Faculty of Chemistry, Jagiellonian University in Krakow, PL 2 Active Text Ltd, Zamoyskiego 27/5, Kraków, PL


Abstract: Very often paper-based archival records contain several layers of different

writing media. In many cases separation of these layers is critical for the retrieval of the

full content of the document (e.g. to identify the content of notes hidden beneath more

recent layers). A number of techniques have been developed to achieve that goal. One of

those techniques is multispectral imaging, used with a great success in forensic

examination of documents as well as in the cultural heritage examinations (e.g. studies of

palimpsests1).

Using a multispectral scanner developed recently by the Active Text Ltd (device presented

during last CeBIT 2015, Hannover, Germany, currently patent pending phase,

http://www.active-text.pl/en/multi-spectral-document-scanner), a large image database

was created for a very broad range of paper-based documents, differing in type and colour

of the paper substrate, writing media used and type of applied document alterations (e.g.

soiling, staining, overlapping text layers). By using different light sources with different

intensities and wavelength characteristics we succeeded in digital removal of organic dirt

present over the tested documents (e.g. stains from tea, coffee, oil etc.). In addition, we

managed to reconstruct text covered by the superficial hand annotations, and other

additional layers (stamps). We also managed to determine which spectra correspond to

individual pigments and dyes and thereby a database has been created containing that

information. With our approach we were able to improve quality of automatic recognition

of the scanned text. This parameter was calculated using the interpretation of scans by

applications such as ABBYY Professional. In the case of soiled documents we observed an

increase in correct recognition of the text included in documents from 63% to 99%. In our

opinion a successful automatic document reading could bring a big improvement in

digitalizing programs carried out at libraries and archives.

Keywords: Multispectral Scanner; Optical Character Recognition 1. Hyperspectral imaging: potential in non-destructive analysis of palimpsests - Rapantzikos, Balas - Image Processing, 2005. ICIP 2005. IEEE International Conference

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SESSION VIII - INTEGRATED RISK MANAGEMENT. PREVENTIVE CONSERVATION

62

Ultraviolet Irradiation on Coverage Woods for Biodeterioration

Control: Contribution to the Preservation of Historic Buildings Rita de Cássia Doria1, 2 1 Faculdade de Letras da Universidade do Porto, PT 2 Universidade Federal do Recôncavo da Bahia, BR


Abstract: Ultraviolet (UV) radiation has been increasingly used in control of fungi activity in

various substrates. The final goal of this ongoing research is to evaluate the cost-benefits of a

UV illumination system on historic buildings’ coverage structures and how it may contribute to

its preservation by preventing/controlling microbiological activity on woods. In this paper,

only the results of some specific objectives will be presented.

Two historic buildings in context of vulnerability were considered as case studies, both built in

the eighteenth century and with the same characteristics: the church of Nossa Senhora da Conceição da Praia in the city of Salvador, Brazil, and the Church of Saint Ildefonso, in Porto, Portugal. The first specific objective was to identify the species of wood that support the structures of the roofs. At the church of Nossa Senhora da Conceição da Praia, the species is the Manilkara elata (Fr. All.) Monach., known in Brazil as Maçaranduba. Those at Saint Ildefonso are still in the process of identification. To detect the presence and to identify fungi on the surface, samples of Manilkara elata were used and fluorescence spectra were obtained with a Quimis spectrofluorometer, with excitation at 407 nm and emission between 300 and 650 nm. Under microscopy, it was possible to confirm the colonization of wood by fungi. There are indications that the isolated fungi are lignocellulolytic, probably asexual, Deuteromycota or Ascomycota, causing soft rot. To determine the UV application conditions and the quantitative method, known as the Beer-Lambert law, the UV absorption value for the timber, Manilkara elata samples will be subjected to ultraviolet-visible spectroscopy (UV / VIS) spectrometer in a Beckman DU640 UV / Vis. The literature studied identifies the value of 2 mm penetration into the surface of the timber. Results will be presented and discussed. Keywords: Wood; Fungi; Biodeterioration; Ultraviolet Radiation

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WORKSHOPS

64

Multi-light Reflectance Technologies: the RTI and PS Techniques

for Museum Collections and Field Work Hendrik Hameeuw1, 2 1 University of Leuven, BE 2 Royal Museums of Art and History, Brussels, BE


Abstract: To understanding the physical characteristics of an object one can alter several

parameters: what is observed can be moved around; the viewpoint can change its perspective toward the subject or the lighting conditions surrounding the object can be adjusted. The multi-light reflectance approach focusses on the latter method. By illuminating a surface from a number of angels; computer algorithms use this varying data to understand and estimate how every pixel will react in every theoretic lighting condition. It is even able to reconstruct the actual three-dimensional shape of the surface, pixel by pixel. This technique has demonstrated and proven its value in the heritage sector over the last fifteen years for standard imaging; conservation monitoring, decipherment of inscriptions, museum display presentations and many other purposes. In this workshop attendees will be introduced in two of the most commonly applied approaches when it comes to multi-light reflectance techniques: Photometric Stereo (PS) and Reflectance Transformation Imaging (RTI). Benefits and disadvantages will be addressed; practical experiences will be communicated and discussed. In a second part a groups demo and a practical processing session of the acquired data will aim to allow the participants to deliberate this approach for themselves. The multi-light techniques are able to register hard to capture details as pretty much no other technology available for the heritage sector can. They present themselves as cost-effective and executable by non-technically trained people. Thanks to the hardware setup, in which commonly used cameras and light sources plays the central role, future updates with better performing equipment gives this approach a technological durability for many more years to come; this includes ultra-high definition photo cameras as well as multi-spectral imaging. Keywords: Multi-Light Reflection; Photometric Stereo; RTI; Multispectral Imaging; 3D Reconstructions

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Light Microscopy and Art Conservation Giancarlo Parma1 1 Leica Microsystems, D


Abstract: Surface inspection, material identification and documentation are important topics in the Art Restoration/Archaeology laboratory. Digital imaging and specialized software translate what we see through the eyepieces of a microscope into a photograph or a measurement, extracting valuable objective data of our samples. This workshop is intended for the general microscopy user to better understand the techniques and be prepared to get the best of them. For this reason we open the agenda of the workshop with a general presentation about microscopy where all basic optical concepts are introduced. Then the workshop goes into detail of the different technics that can be used in the restoration of paintings and archaeological finds. Starting point is the use of stereomicroscopes and it ability to provide a 3D perception at low magnification. After that fluorescence techniques for microscopy and stereomicroscopy that make use of different wavelengths to excite natural substrates and allow their emission thus providing valuable information about its nature and origin. Finally we will focus the workshop on the new microscopy technologies that allow a very precise imaging of the surface of virtually any material and its characterization: Digital Microscopy to extend the capabilities of traditional stereomicroscopes and high performance techniques like Confocal Microscopy, Interferometry and Focus Variation. In the last part of the workshop, attendees are encouraged to test their samples with the techniques previously explained. Groups of five people maximum, with the support of an experienced user, can freely work in one hour shifts with any of the three instruments available. Keywords: Microscopy; Stereomicroscopy; Confocal; Fluorescence

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On the Application of X-Rays for Research and Characterization

of Cultural Heritage Objects / Materials Carlos Sá1 1 CEMUP, Centro de Materiais da Universidade do Porto, PT


Abstract: The discover of the X-ray radiation by Wilhelm Röntgen in 1895, has enabled new view sights on the material objects - natural and manmade - that surround us, giving a new perception of their macro and micro structure, and it was the source for a deeper knowledge of the intimate nature and structure of the matter. First, with X-rays it became possible to get images - radiography - from inner (or hidden) parts of opaque and thick bodies, taking advantage of the large penetration depth, and from the exponential abortion law (with mass thickness) and from composition differential absorption. X-ray imaging made a long way to modern X-ray tomography and advanced X-ray microscopy, with a broad range of fields of application in science and technology. Second, the short wavelength and large quantum energy of X-rays, imply a complex interaction - absorption, scattering, diffraction, fluorescence - with matter (amorphous or crystalline), generating extended information about the elemental composition and order at the atomic and molecular level. In reason of these properties, X-rays are used in many essential technologies, and modern and advanced instruments, as primary and/or secondary radiation, for imaging, for elemental analysis and for structural characterization. At CEMUP, X-rays find application in Scanning Electron Microscopy with X-ray Microanalysis (SEM/EDS) enabling local elemental composition analysis (X-ray emission at the micron size, nondestructive) of the exposed surfaces of objects in the course of microscopy examination, and in X-ray Photoelectron Spectroscopy, as primary radiation for detailed analysis (elemental composition and chemistry) of the top layer surface (thickness of less than 10 nm) of solid materials. These techniques find extended applications for the identification of composition, manufacture technology, the deterioration process and conservation of cultural heritage objects / materials, as it will be shown in the workshop.

Keywords: X-rays; XRD; XRF; SEM/EDX; XPS

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X-ray Fluorescence: Principles and Practice Lee Drake1, 2 1 Bruker, US 2 University of New Mexico, US


Abstract: With the advent of portable scientific instrumentation, the capabilities have

been brought to the field. However, the use of laboratory-quality equipment requires an

understanding of the principles involved. These principles are important not just for a

general understanding of X-ray fluorescence (XRF) as a technique, but critical for the

application of XRF as a robust method to answer questions in cultural heritage. The

workshop will cover the basics of XRF, along with the mathematical and statistical principles

that underlie analysis. These include:

1. The basics of XRF, including the physics of photon-atom interactions

2. An introduction to qualitative analysis of spectra

3. The critical parameters to select for analysis based on elements of interest and matrix

4. The quantification of data based on empirical reference standards

5. Use of Bayesian deconvolution to identify elements and produce net photon counts

6. Sampling approaches to address the analysis of heterogeneous materials 7. Statistical approaches to analyzing quantitative and semi-quantitative data 8. Examples of successful uses of XRF technology, including geochemical provenance, pigment characterization, and mineral identification/composition 9. An introduction to non-conventional uses, such as layer analysis, plant nutrition, and other uses of the spectra

Emphasis in the workshop will be placed on the analysis of heterogeneous samples, though homogenization techniques will also be highlighted. The workshop will also make use of the lessons learned by Bruker in cultural heritage, including common elemental overlaps, common misperceptions, and techniques to improve analysis of elements which can threaten heritage materials. This includes identification of troublesome elements such as sulfur, chlorine, arsenic, lead, and mercury. Time will also be set aside for questions from participants. Keywords: X-ray Fluorescence; Methodology; Qualitative; Quantitative

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Using Natural Light in Historic Properties David Thickett1, Boris Pretzel2 1 English Heritage, UK 2 Victoria & Albert Museum, UK Corresponding authors: [email protected]; [email protected]

Abstract: Fitting lighting into historic properties can be problematic. It often leads to loss of

fabrics and alters atmospheres. A major proportion of light came from windows and using

daylight offers energy and carbon footprint savings. Many historic properties had gardens or

landscaping and this was designed to be viewed from certain rooms. Using daylight is much

more challenging than artificial lighting, although maintaining bulbs can cause significant

changes if bulb type, dimming and positioning are not controlled.

This workshop will train participants in some tools that can be used to maintain day lighting

levels in historic properties. The sensitivity of the collection is key and can be difficult to

determine with very mixed collections. The CCI Light Calculation Tool was developed to answer

this problem. Micro-fading has been used to check the remaining light sensitivity of objects on

continuous display. Although its use will not be demonstrated (equipment is expensive and

measurements require significant time), using and interpreting results will be discussed.

Light plans are a way to determine blind positions to balance viewing of collections with their

preservation. The information required and approach adopted will be demonstrated. Spot monitoring of levels under changing natural light is very time consuming to collect representative data. Data-loggers and radio telemetry systems automate this process, but are expensive and difficult to place to be representative. Blue wool dosimeters have been used to measure annual light doses inexpensively. A less accurate manual assessment method or a more accurate method with a Chroma meter or colorimeter or spectrometer will be demonstrated. Best practices will be explained. The use of UV, neutral density filters, blinds and screens will be discussed and potential drawbacks explained. The use of Apps to determine sun position throughout the year and its impact on light levels and management will be demonstrated. Keywords: Natural Light; Historic Properties; Atmosphere; Energy Saving; Risk Management

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Microfading Testing: A tool for Informed Policy Development

and Materials Testing Jacob Thomas1, Tomasz Łojewski2 1Department of Conservation, Gothenburg University, SE 2Department of Chemistry, Jagiellonian University in Krakow, PL Corresponding authors: [email protected]; [email protected]

Abstract: Microfading testing (MFT) is a technique to rapidly and directly evaluate the

lightfastness of a heritage object in a particular environment. This information can be used to

develop display and lighting policies tailored for an object.

MFT was developed by Paul Whitmore in the mid-1990s and received immediate interest from

the conservation community with regard to method development. During the last 10 years

emphasis has shifted from method development to development and characterization of the

instrumentation. In the intervening years there has been a proliferation of instrument designs

with the retro-reflective probe head design becoming quite common. Other researchers have

focused on issues of reciprocity and its failure as well as means to ensure light source stability

and thereby more reproducible measurements. After ca 20 years the technique is mature with

methods developed for a broad range of materials, nearly, but not quite, the entire breadth of

museum collections.

Despite the promise of the technique and the widespread interest, it is not widely adopted by

heritage institutions. A possible explanation is that MFT is targeted at experienced users, i.e.

the instruments are not terribly user friendly both in terms of hardware and software.

Converting the MFT from a researcher’s tool into a ‘plug n play’ collection survey tool has been

the focus of several year’s research and development at Jagiellonian University and

collaborating institutions.

This workshop will briefly present the history and technology of MFT to date followed by

demonstrations of instrument characterization, operation and data interpretation. The new

fully automated MFT will also be presented as a possible survey tool. The workshop will use

hands on, guided case study format to present the instrumentation and its application to

attendees with a goal to increase their awareness of MFT and the possibilities of using it in

their decision making process.

Keywords: Microfading Testing (MFT); Photodegradation; Lighting Policy; Preventive Conservation; Automated Testing

71

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