ICON Paintings Group conference

ICON Paintings Group Conference

Seeing Further: An Overview of Advances in Digital Imaging and
Investigations.
at the Wallace Collection
Hertford House
Manchester Square
London W1U 3BN
Friday, 24 April 2009

As a fundamental element of technical examination, scientific
imaging has helped conservators to better understand objects for
many years. This conference will explore a number of traditional and
cutting-edge, digital imaging techniques that are currently being
used and developed in the field of imaging science and their
applications in paintings' conservation.

Non-invasive, investigative techniques discussed include: TeraHertz
Time Domain Spectroscopy (THz-TDS) for the imaging of hidden paint
layers; multi-spectral cameras which enable the 'virtual' removal of
discoloured varnishes and overpaint; infrared vidicon technology and
its use in the examination of paintings; and the MultiEncode
instrument, which provides an object's 'defect signature', which can
be used to verify authenticity, and the holograms and/or shearograms
of objects studied to assess the stresses that paintings undergo
during handling and transport.

As well as discussing the techniques and technology employed to
capture images there will also be a number of fascinating case
studies. The conference aims to examine the types and quality of
images produced for specific purposes and how to retrieve, label,
interpret, handle and store single and sets of images correctly for
more meaningful results.

The morning will be devoted to two keynote speakers:

    Dr Haida Liang
    "Imaging Science in Conservation - Current Developments and
    Future Prospects"

        Scientific imaging has been an integral part of 'technical
        examination' ever since the beginning of conservation
        science. Owing to the demands in astronomy, remote sensing
        and medicine, the rapid developments in imaging science in
        the last 30 years have firmly established new disciplines
        such as biomedical imaging. In the last 15 years, research
        in the application of imaging science to art conservation
        has also flourished as a result of the achievements in other
        fields where non-invasive imaging is in high demand. An
        overview of current developments in imaging science
        applications in art conservation will be presented with
        particular emphasis on non-invasive imaging techniques in
        the visible and the infrared. The future of imaging science
        in conservation will be discussed

    Dr Nick Eastaugh
    "After Image: The Practical Utilisation of Digital Imagery for
    Conservation and Scientific Examination of Paintings"

        Taking the picture is only one step in a process that
        extends from identifying why you need to acquire a
        particular kind of image through to its detailed
        interpretation. This talk will therefore focus not on the
        technology of image acquisition, but how we use such images
        to explore commonly faced problems. Questions that will be
        tackled include: what kind of images and image qualities are
        generally needed for different purposes; how we can attach
        useful information to images to help with documentation,
        interpretation and image retrieval; handling large and
        complex (as well as interrelated sets of) images; and using
        image analysis techniques to extract hidden meaning.

The afternoon sessions will be devoted to case studies:

    Presented by Joris Dik
    'TeraHertz Imaging of Hidden Paint Layers on Canvas'

        This paper will focus on the use of TeraHertz Time Domain
        Spectroscopy (THz-TDS) in the imaging of hidden paint
        layers. We prepared a test canvas with several strokes of
        umber covered with lead white such that both colour and
        topography of these strokes was fully covered. With THz-TDS
        we managed to chart all reflections of the interfaces in the
        paint stratigraphy. By carrying out these measurements on a
        pixel-by-pixel basis, we were able to visualise the
        distribution of the hidden umber layers as well as their
        variations in thickness. In the outlook we will compare THz
        with other, existing techniques and sketch the technique's
        potential as well as its limitations.

    Jean Penicaut of Lumiere Technology
    Title to be announced

        Jean Penicaut founded Lumiere Technology, a private, not
        commercially based, French institute together with Pascal
        Cotte. This Institute has developed a multi-spectral camera
        that digitizes at 240 Million pixels across the spectrum
        ranging from UV right through to Infrared, opening up new
        ways of research for the Fine Arts. Beyond making wonderful
        pictures, in both the visible and invisible spectra, this
        camera measures the pigment spectrum used by painters and
        conservators in each pixel, removing the influence of the
        varnish by virtual means.  Jean will show samples of this
        digitization process on some of Leonardo's paintings and on
        two versions of Van Gogh's The Bedroom at Arles from the Van
        Gogh Museum and the Art Institute of Chicago.

    Tager Stonor Richardson
    'Mobile Infrared Reflectography: The Challenges and Rewarding
    Results of Working on Site'

        Following a brief introduction to the infrared vidicon
        technology employed, and its history of use examining art
        objects, this talk will encompass the specific challenges of
        working on site to produce composite infrared reflectogram
        mosaics comprising often hundreds of sub-images. Reflecting
        upon the experience of travelling throughout the UK with
        bulky and delicate equipment and the challenges of
        maintaining parallel alignment whilst scanning amongst soft
        furnishings and historic interiors, TSR will discuss how
        they have developed their approach over the past 7 years.

        This talk will be illustrated with examples of underdrawing
        found on paintings in the Collection of the Society of
        Antiquaries, including Hans Eworth's panel of Mary I and
        early English paintings depicting the Life of St.
        Etheldreda. These findings will be put into context drawing
        upon examples from other collections examined by TSR,
        touching upon issues of authorship and workshop practise.
        Participation in research projects for public collections
        will be discussed alongside the challenges of developing the
        body of knowledge when working for private clients.

    Tim Green
    'The MultiEncode Instrument and its use to Measure Strain in
    Paintings'

    'MultiEncode' is a collaboration between Tate Conservation
    Department, the Centre Spatial de Liege (CSL), the Institute of
    Electronic Structure and Laser (FORTH.IESL) in Crete, the
    Foundation for Research and Technology Hellas, the Institut fur
    Technische Optik (ITO) and Optrion s.a., the National Gallery of
    Athens - Alexandos Soutzos Museum. The MultiEncode instrument
    comprises three complementary detection systems, all of which
    use a common laser source, share optical components, and are
    operated using a single software package.  Taken together, these
    three techniques provide an object's "defect signature", which
    can then be used to verify that object's authenticity in cases
    of fraud or theft.  However, at Tate by monitoring changes in
    the holograms and/or shearograms of objects as a function of
    time, Tate hopes to glean information regarding deterioration as
    a result of handling and transport. Results from the preliminary
    analysis of paintings from the Tate collection will be
    presented.

Members UKP75; non-members UKP95; students UKP45

To encourage forward planning there is an early-bird policy,
bookings after Easter shall be UKP5 more expensive

To pay by cheque, make cheques payable to Institute of Conservation
and send them to

    Rebecca Gregg
    9 Cork Street
    London W1S 3LL

To pay by credit card please contact Dubravka Vukcevic at ICON head
office on +44 20 7785 3807


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                  Conservation DistList Instance 22:51
                 Distributed: Wednesday, March 11, 2009
                       Message Id: cdl-22-51-016
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