Harnessing Digital Technology for Conservation Documentation

7/28/2019 Harnessing Digital Technology for Conservation Documentation

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Harnessing Digital Technology forConservation Documentation

By Rand Eppich and Francesca PiquIn a small computer lab at the Getty Conservation Institute,Irene Sen and a fellow conservator are discussing the GCI'swork on The Last Judgment mosaic in Prague. Located on theexterior of St. Vitus Cathedral, the 14th-century glass mosaichas suffered from pollution and the extremes of the climate

in the Czech Republic. Sen, a GCI research fellow, sits downat a computer keyboard and opens an electronic file thatcontains all the graphic information concerning the mosaic.An image of the multicolored mosaic appears on the monitor,followed by an overlay of graphic and written notes on themosaic's condition. The fine details are not apparent at first,so Sen enlarges an area of the mosaic near therepresentation of the central figure of Christ in judgment.The discussion turns to previous conservation interventions.Sen moves the mouse over a button that controls layeredinformation about the mosaic. After a few clicks, most of theinformation disappears, except for red lines that cross themosaic. Sen explains that these lines show where the mosaicwas cut to be detached in the late 19th century. Shehighlights the area and selects "print"; soon she has a color

print of the part of the mosaic under discussion.As in many of the GCI's recent field projects, The Last Judgment mosaic project's graphic documentation is beingcarried out on site in a way that can be easily transferred todigital form. Photographic and computer technology, often inconjunction with traditional methods of documentation, now
http://www.getty.edu/conservation/our_projects/field_projects/vitus/http://www.getty.edu/conservation/our_projects/field_projects/vitus/http://www.getty.edu/conservation/our_projects/field_projects/vitus/http://www.getty.edu/conservation/our_projects/field_projects/vitus/


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provide the basic tools for the recording and manipulation of data concerning the original technique, conservation history,and conservation intervention of an object, mural, mosaic, orsite, as well as its existing state of conservation.

An example of graphic representation of some of the conservation informationrecorded for the central panel of TheLast Judgment mosaic on the GoldenGate of St. Vitus Cathedral in PragueCastle. At the end of the 19th century,the mosaic was cut into 273 sectionsand removed from the cathedral facade.The drawing indicates the edges of thedetached sections, as well as areas of original and new tesserae and traces of the original gold gilding. The mosaic's


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conservation is a collaboration betweenthe Office of the President of the CzechRepublic and the GCI.

The center of the GCI's computer documentation work is thedigital lab, which houses imaging equipment and computersloaded with some of the latest software programs. Createdover three years ago by the Institute's Conservation group topromote digital documentation, the digital lab has threeobjectives: support for documentation in field campaigns,training, and research.When a site which might contain mosaics, murals, and

architectural elements or an art object is selected forconservation, the first task of the conservation team is tocarry out an in-depth examination. This includes the graphicrecording of the site or object's condition. By studying allaspects of a site or object, one acquires an accurateunderstanding of its present state (including the nature andextent of deterioration), previous interventions, the originaltechnique, and the effects of past damage.Condition recording is an essential component of aconservation project. It provides the basis of knowledge forproject management, investigation, and the development of a conservation plan. Information gained from conditionrecording supports condition assessment, enables costanalysis in project management, and guides the use of resources. It also provides information for fund-raising, the

development of partnerships, and publishing.In addition, condition recording helps identify needs andpriorities for investigation and treatment planning.Conservators gain significant understanding of an object orsite while recording its features. The type, extent, andlocation of damage are crucial to understanding the


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processes and causes of deterioration; they also will indicatethe need for additional investigation. Furthermore, in-depthexamination reveals the effectiveness of methods andmaterials used in previous interventions.During treatment, graphic condition recording is used as areference and as a basis for annotation. It remains a keydocument for the future, providing a foundation forevaluating changes in the conserved object or site.In the past, all this information was collected in great detail,in notebooks, on paper, and on acetate. It was, however,tedious and time consuming to modify information in this

form and to duplicate, disseminate, manage, and store thedata. The use of computer technology to record andmanipulate the documentation allows greater ease andflexibility in working with the variety and amount of information required and collected in aconservation project.

The conservationteam at work ondigitaldocumentation of 16th-century wallpaintings by Italian

artist FilippoPaladini, located inthe Paladini Chapelof the Grandmaster'sPalace in Malta.Graphic information


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An example of this was the recentcondition assessment of the 16th-century retablo in Yanhuitln in Oaxaca,Mexico (see The Retablo of Yanhuitln ). Theretablo, a wooden altarpieceapproximately 19 meters in height, islocated in the apse of the Church of Santo Domingo. Considered one of thecountry's most important examples of colonial art, it has suffered damagefrom water, insects, and seismic

activity. In the early stages of theproject, the conservators decided thatas part of the assessment phase, thecondition recording would be done indigital form.During a documentation campaign,Irene Sen installed a desktopcomputer with Spanish versions of AutoCAD and Adobe PhotoShop in the dimly lit church.Balancing on scaffolding, the documentation team firstrecorded the condition information (i.e., cracks, paint loss,flaking, insect damage) in the traditional manner by markingon acetate sheets over photographs of sections of theretablo. Conditions were then redrawn in the computer overonscreen digital photographs of the altarpiece.The electronic files created by Sen consist of images andgraphic notations containing conservation information andtext. These sets of information are overlaid to create acombined visual and written record of the problems of theretablo a record that can guide the development of aconservation strategy.

was collectedtraditionally andtransferred to digitalform directly in frontof the paintings. Thisreduces mistakesthat occur when datatranscription iscarried out awayfrom a site. Thedocumentation ispart of a

collaborationbetween the VallettaRehabilitationProject, theCourtauld Instituteof Art, and the GCI.Photo: Ray Bondin.
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The use of digital technology is not always convenient in thefield. In Yanhuitln, obstacles to the computer's use includedan irregular power supply, copious amounts of dust, and theneed to halt work during church services. But enduring thesedifficulties was worth it. Using the computer in the field as atool in conservation assessment enabled the project team tocreate a detailed and comprehensive digital record of thestate of the retablo, eliminating any possible mistakes thatcould have occurred during transcription of information, hadit been done far away from the altarpiece.As part of the retablo's condition recording, Sen trained

Javier Salazar of Mexico's Instituto Nacional de Antropologae Historia (INAH) in the use of this technology. In two weeks,despite interruptions, Sen and Salazar made a good start oncollecting information in digital form. After Sen's return tothe GCI, Salazar remained on site and completed thecondition recording.Conservators at the GCI who have used computer-aided toolsfind that digital documentation records offer all theadvantages of digital formats, including infinitereproducibility. They can be edited, duplicated, stored,shared, and even e-mailed. This can all be done more easilyand cost-effectively than if the records were in paper form.In addition, data analysis is greatly improved by the use of computer-based technologies, which offer capabilitiesimpossible to achieve in exclusively manual systems.

GCI project


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On the Mediterranean coast of Israel, aspart of a mosaics project undertaken by theGCI and the Israel Antiquities Authority,digital condition recording is being usedat the ancient site of Caesarea to trackchanges in the condition of fivemosaics. The mosaics, which arevulnerable to the damaging effects of rain, wind, salt, and heavy touristtraffic, are being used to test andevaluate four different protective

measures. As part of the test,conservators examine the mosaicsmonthly and update the conditionrecord for each mosaic. This procedureis easily accomplished when the dataare in digital form. Furthermore,because the computerized graphic dataare quantifiable, the digitized conditionrecord will show more precisely thecomparative rates of deterioration andthe efficacy of the protective measures.Because technology is developing sorapidly, the GCI digital lab continues toreview new and existing technologies

and their possible applications to conservation. Determiningthe best possible method for conservators to record ingraphic form is another element of the lab's research. Forexample, the most efficient way to obtain a digital documenton site is to record on the computer directly. However, whenit is not practical for laptop computers to be brought into thefield, the digital lab has developed protocols for traditional

specialist FrancescaPiqu at the site of Horvat Minnim inIsrael graphicallyrecording conditionsonto transparentsheets positionedover photographs of the mosaic. Thesheets were thenscanned to createlayers of

information, indigital form. Therecording, part of the assessment of eighth-centurymosaics in theUmayyad Palace, isa component of a

collaborative projectbetween the IsraelAntiquities Authorityand the GCI.Photo: Frank Long.
http://www.getty.edu/conservation/our_projects/field_projects/mosaics/http://www.getty.edu/conservation/our_projects/field_projects/mosaics/


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recording that allow easy transfer of data and images intoelectronic form.By studying new software, hardware, and techniques, and byconducting experiments, the digital lab seeks to improve theefficiency of conservators by providing information on thebenefits and potential pitfalls of selected tools.Last May, Evin Erder, a GCI research fellow, used a totalstation (a survey instrument that measures distances andangles electronically) to gather data on the Tel Dan gateway,a 1800 B.C.E. mud-brick arch structure in northern Israel. Itis among the earliest known examples of an arched

structure, and although protected by a shelter, it continuesto deteriorate. Using the instrument, Erder was able topainstakingly record cracks and the deformation of thefacade in three dimensions. These data have been combinedwith a photogrammetric computer model to provide acomplete picture of the gate. During future monitoring, theinformation can help determine if the cracks are changingand if material is being lost from the structure. Theinnovative use of this methodology in the Tel Dan gatewayproject is an effort to establish more effective techniques forrecording three-dimensional data on heritage sites. Thesedata provide a complete picture of the structure that wouldotherwise be impossible if only plans, sections, andelevations were used. The data can also be used to helprecreate how the arch might have appeared when firstconstructed.


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Choices about how to apply digitaltechnology to conservationdocumentation should be guided by thespecific needs and purposes of aproject. Depending upon the resourcesavailable and the characteristics of thesite environment, a variety of more orless sophisticated tools ranging fromtraditional pen and paper, throughlaptops in the field, to digitalphotogrammetry can be employed. In

every instance, planning prior to fieldcampaigns is essential to best gatherthe information for effective use.Because the bulk of documentationinformation on GCI projects isultimately transformed into digital data,a close working relationship hasdeveloped between field conservatorsand computer specialists on staff. Thiscollaboration has greatly enhanced thedevelopment and improvement of methods for graphic recording.The integration of digital tools into the conservationdocumentation process is still in its early stages.Nevertheless, it holds the promise of vastly increasing thebody of information easily available to conservation teams inthe field, in the lab, and for coordination and comparisonbetween similar projects, thereby facilitating theeffectiveness of their work.Rand Eppich is a research fellow and Francesca Piquis a project specialist in the GCI's Conservation group.

GCI research fellowEvin Erder using atotal station torecord three-dimensionalinformation on thelocation of cracksand other conditionsof the 18th-centuryB.C.E. mud-brickgateway at the siteof Tel Dan in Israel.

The data collected inthis precise way canbe used to monitorchanges in the gate.The documentationwas part of a projectof the IsraelAntiquities Authority

and the GCI.Photo: Rand Eppich.


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Harnessing Digital Technology for Conservation Documentation