Tag Archives: art conservation

Damage assessment of heritage objects and methods used in their preventive conservation. A talk by Dr Marianne Odlyha.

This post was contributed by Bryony Stewart-Seume, a Senior Administrator in the School of Science.

Science Week continued with a lecture given by Dr Marianne Odlyha, concerning ways in which heritage objects can be damaged over time, and recent research into the methods which can be employed to minimise risk and decay. The lecture was well attended and well received.

After being introduced by Professor Nick Keep, the Dean of the School of Science, Dr Odlyha gave some background to the project on which she has been working for some time; “Measurement, Effect Assessment and Mitigation of Pollutant Impact on Movable Cultural Assets – Innovative Research for Market Transfer.” Essentially this research looks at the different environments in which moveable cultural objects (paintings, artefacts, tapestries, etc…) are displayed, stored or transported and to what pollutants these conditions may subject the objects.

Dr Odlyha began by explaining that the research is an interdisciplinary area; it encompasses many academic fields ranging from Art History to hardcore Science. The key objective of the work is to retard the degradation and decay of objects as much as possible. A description of the corrosion found in the organ pipes in the St James Church in Lübeck, Germany was given as a case study, and as an example of a situation that could have benefitted greatly from better environmental monitoring systems.  The organ is now sadly in a terrible state, and is unplayable.

It is of course unfortunate that the material of choice for the construction of organs (oak) is a high emitter of damaging gases. This issue is exacerbated by the fact that organs (and other such items of cultural worth) are often located in places with central heating, which is there for the comfort and convenience of the audience.

I was surprised that, despite being a method of display for many years, even something as apparently innocuous as the wood from which a case is built can cause damage over time. Plywood, for example, gives off very strong emissions; of course the cases in which paintings are kept in storage (Dr Odlyha used the example of the Tate’s store to highlight her point) are primarily built from this material. There is a legitimate economic reason for this, but perhaps this is offset against the damage potential?  While showcases will keep out much of the outside pollutants, it seems that it is just as important to be aware that the climate on the inside will also have a noticeable effect on the item on display.

Similarly, the practice of using varnish on a painting is an old one, and was originally thought to do some good. It does have the effect of darkening the image and enhancing colour saturation; however, as Dr Odlyha told us, over time the painting may start to yellow. It is not only the varnish itself that can inflict damage on the painting, but also the method of cleaning employed. It is also important to know that when we find a solution that minimises the damage potential of one polluting factor, we may have merely introduced another. The cycle of material selection/damage dealt is apparently perpetual, and it is only through cutting edge, up to the minute research that we can hope to do what can be considered best for our heritage.

There are options, though, for mitigating the risks to movable objects; one of those being a so-called ‘Micro-Climate Frame’. The conditions on the insides of the frames are measured using custom-made dosimeters and compared with the ambient atmosphere. Fluctuations in the surroundings have proven to be far more severe than within the frames themselves. Of course this is good news, and what is expected, but Dr Odlyha admitted that there is still much research to be done in this area.

You can find out more about Dr Odlyha’s research at http://www.memori-project.eu/memori_project.html

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Eye-tracking technology: Understanding what we really see

This post was contributed by Guy Collender from Birkbeck’s Department of External Relations.

Our eyes are imperfect, but we don’t notice their limitations. This reality and its implications for artists and film-makers were clearly shown during a Science Week lecture at Birkbeck.

There was audience participation too, as the eye movements of volunteers were tracked with high-speed infrared cameras to prove what happens when people look at pictures and films.

Dr Tim Smith, of the Department of Psychological Sciences at Birkbeck, shared his research during the talk, including his work with Tate Britain to help restore a famous painting.

He began his talk on Wednesday 29 March by outlining the theory of vision science – the study of how people view, perceive and remember visual scenes, and how this influences their actions.

In practice, our eyes often fail to detect changes in the background because they can only focus on a small proportion of the visual field and process a limited amount of information. This “phenomenon of change blindness” is significant as it means viewers can be distracted from what is happening. Smith said: “What we think we see is rarely actually what we see.”

A masterpiece restored

Destruction of Pompeii and Herculaneum by John Martin

Destruction of Pompeii and Herculaneum by John Martin

Art and science are often closely linked, and Smith demonstrated how he has applied insights from vision science to inform art conservation.

In 2010, Tate Britain decided to attempt a restoration of the flood-damaged 19th century masterpiece Destruction of Pompeii and Herculaneum by John Martin. A large section of the dramatic painting, which documents the eruption of Mount Vesuvius, was lost, and Smith was asked for his expertise to recommend how to remedy this. He used eye-tracking equipment to assess how viewers would look at four prototypes of restored versions of the painting: fully restored, restored but with less detail in the filled section, muted colour in the filled section, or a neutrally coloured infill.

His findings showed that the eyes of viewers were drawn to the edges of the lost section when it was filled with a muted or neutral colour, and this detracted from the original intention of the artist as this was where the mouth of the volcano was supposed to be.

Informed by Smith’s research, Tate conservator Sarah Maisey embarked on a reversible reconstruction of the lost section. Some detail was omitted in the reconstructed section, allowing viewers to see the entire main content of the painting while spending most of their time viewing the original sections. The painting was exhibited during the recent John Martin Apocalypse exhibition at Tate Britain, and Smith said the reaction to the restoration was “overwhelmingly positive.”

Cinematic continuity
Smith continued by demonstrating how gaze patterns generated by eye-tracking technology also show how people watch films. He outlined the history of film and editing conventions, and explained how film-makers replicate the way people attend to, and perceive, reality. This includes focusing on motion, helps lead to a seamless representation, and means that edits largely go unnoticed in today’s films, where the average duration of a shot is only 2.5 seconds. Smith added: “If we compose edited sequences according to these conventions, we can make viewers blind to a large proportion of the actual cuts.”

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