Barrie Schwortz offers us a final report on the 2015 Shroud of Turin Exposition titled The 2015 Exposition – A Personal Report by Barrie Schwortz. I found this paragraph particularly interesting:
I have noticed that since the 2002 restoration of the Shroud, the Turin authorities have had certain difficulties in adjusting the lighting to portray the Shroud in its natural color when on public display. That may be because a whiter sheet was sewn to the back of the Shroud during the 2002 intervention, thus lowering the apparent contrast of the image itself. I discussed this with Bruno Barberis while in Turin and he explained that this year, to help compensate for this lowered contrast, the organizers tested and calibrated the spectral characteristics of the lighting used to maximize visual contrast in the image. However, this required using a portion of the visible spectrum that in part neutralized the yellow color of the cloth itself, making it appear more grayish in tone. To help restore the warm color appearance of the Shroud, the organizers chose to surround the cloth with a blue frame. Any art or photography student knows that doing so makes the object within the frame appear warmer in tone. There is no doubt that the Turin authorities approached this carefully and thoughtfully and made the best compromise possible between contrast and color, so that viewing the Shroud was a truly positive experience for everyone.
Oh, to be reminded of 2002 again.
I have a hypothesis… that the original Holland backing cloth was also too bright for the Shroud, so it was smeared with madder dye where it was visible – at the cut off corners of the Shroud – some of which also got smeared onto the Shroud itself, which is what Rogers found when he discovered his water soluble gum.
I’m grateful to Barrie for explaining the otherwise rather incongruous blue wooden frame in which the Shroud was exhibited. It may have had some effect in ‘warming up’ the Shroud, but, in view of the blue light which was the only illumination, it also had the effect of glowing somewhat ethereally itself, while the rich red curtains which surrounded the whole arrangement faded into a dull purple.
It would have been easier to use a better color of backing cloth.
In the 16th century, probably. In 2002, I think there was a requirement for undyed, unbleached, un-everything linen, and the colour was incidental. Perhaps it could have been ‘aged’ in an over for a short time though.
Here a question regarding the problem of
possible color transfer : how to test this hypothesis ?
Have you a suggestion?
I think that advanced analyses can be useful
to solve also this problem…