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"Ballard, Mary" <[log in to unmask]>
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Textile Conservators <[log in to unmask]>
Date:
Tue, 4 Mar 2008 11:48:15 -0500
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An article sent to us by T. Rose Holdcraft:

Shroud of Turin Gets High-Def Scrutiny
Rossella Lorenzi, Discovery News

Feb. 28, 2008 -- The Turin shroud, the 14- by 4-foot linen long
believed to have been wrapped around Jesus' body after the
crucifixion, has entered the digital age.

A huge 12.8 billion-pixel image was made of the linen, on which the
smudged outline of the body of a man is indelibly impressed. The image
was made following a Vatican request to obtain the most detailed
reproduction of the yellowing ancient cloth. The technology allows a
level of scrutiny of the linen as never achieved before.

"The Shroud has been photographed in high definition for the first
time. We have stitched together 1,600 shots, each the size of a credit
card, to create a huge photo which is almost 1,300 times stronger than
a picture taken with a 10 million pixel digital camera," Mauro
Gavinelli, technical supervisor at HAL9000, a company specializing in
art photography, told Discovery News.

According to Gavinelli, who also created the world's
highest-resolution photo when he digitalized Da Vinci's "Last Supper,"
the technology allows researchers to analyze the shroud in
unprecedented detail.

"It is like looking at the Shroud through a microscope. You can see
the threads, the fibers that make these threads, the damage that the
shroud has suffered over the years," Gavinelli said.

As hundreds of shots were taken using sophisticated equipment, the
process, itself, was recorded by the British Broadcasting Company,
which will be airing a program about the project on the Saturday
before Easter.

"It was fascinating. Seeing the shroud within a few inches is a unique
experience. The image is very visible, it isn't true at all that it is
fading," said David Rolfe, director of the BBC documentary.

Kept rolled up in a silver casket, the shroud has been shown only five
times in the past century. When it last went on public display in
2000, more than three million people saw it. The next public display
will be in 2025.

Scientific interest in the cloth, which has survived several blazes
since its existence, began in 1898, when it was photographed by the
lawyer, Secondo Pia. The negatives revealed the image of a bearded man
with pierced wrists and feet and a bloodstained head.

Venerated by many Catholics as proof that Christ was resurrected from
the grave, the shroud was eventually dismissed as a brilliant,
medieval fake twenty years ago. Carbon-14 tests at three reputable
laboratories in Oxford, Zurich and Tucson, dated it to between 1260
and 1390.

After the tests, the Oxford laboratory's founding director, Edward
Hall, told journalists: "Someone just got a bit of linen, faked it up
and flogged it."

But shroud scholars, known as sindonologists, have always argued that
no medieval forger could either have produced such an accurate fake or
anticipated the invention of photography.

Speculation about the linen cloth continued as well as debates over
the validity of the carbon-14 tests.

"There is the possibility that new carbon-14 tests today will produce
different results. A new hypothesis has been formulated, and it deals
with information that wasn't available twenty years ago," Rolfe said.

The new hypothesis, developed by "another contributor to the film,"
according to a University of Oxford press release, is being tested by
Christopher Ramsey, director of the Oxford Radiocarbon Accelerator
Unit. The results will be revealed in the documentary

Ramsey, a top expert in the use of carbon dating in archeological
research, is skeptical the new theory will prove that the carbon
dating tests were inaccurate.

"I keep an open mind--as I would about any scientific investigation.
However, my strong intuition, based on my experience in this field, is
that the new hypothesis will not challenge the accuracy of the
original radiocarbon dating exercise," Ramsey said in a statement.

The new theory would only require two percent contamination to skew
the results by 1,500 years--not much considering the shroud's long
history, handling and exposure to the elements.

"There is nothing new, as far as I know, which would change the
situation. These ideas have been raised previously and none has been
shown to have any merit. Many hypotheses, such as contamination, fire
changing the results and more dubious assertions have been made, but
none has seriously challenged the 1988 dating," Timothy Jull, a
professor in geosciences at the University of Arizona who specializes
in carbon dating, told Discovery News.

Indeed, numerous theories, such as a plastic coating built up on the
linen by millions of tiny micro-organisms, have been presented to
explain how the radiocarbon tests could have been inaccurate. All have
been rejected by the scientific community.

In 1998, Ramsey himself tested the possibility that carboxylation of
the cellulose in the linen during the 1532 fire could have produced a
younger dating, but concluded that "carboxylation is not a systematic
source of error in the dating of cellulose-containing materials such
as the linen in the Shroud of Turin."

The latest research, by the late Ray Rogers, suggested that the sample
used to test the age of the shroud in 1988 was taken from a medieval
rewoven area of the shroud.

Whatever the outcome of Ramsey's tests, the high definition images are
expected to add new complexity to one of the most controversial relics
in Christendom.

"The Shroud has yielded surprises each time it is subjected to a new
form of reproduction. The first time it was photographed, it revealed
its negative characteristics. Then it was scanned and turned into a
tridimensional image. Now we have filmed it in high definition. We are
already seeing some interesting effects," Rolfe said.






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