I too have followed the investigation into the Shroud of Turin since the days of the VP8 Image analyzer and the STURP Investigation, There is some information not presented in the videos, or which is inadequately covered, that I'd like to bring forth.
The image is faint. Very faint. The images we usually see are contrast-enhanced to bring out the detail of the image, to a more visibly obvious level. The image is so faint that the cloth must be viewed from a distance for the image to be seen at all. When you get too close to it, the faint differences in the fiber colors just merges together into one color or shade of color.
The image is in the "negative", probably due to the method of production. It was not seen as a positive until the photographs of Secundo Pio in the early 1900's. A positive image was seen to occur on the negative plates of his photography sesstion.
The image is ONLY on the surface. The VERY surface. it only goes one fiber deep into the cloth. Not one thread deep, but on FIBER deep on the very surface threads of the weave.
The image was produced by a process of "dehydrative oxidation" - a fancy way of saying burned or scorched. There is no pigment in the image as would be present in a painting. The color of the very surface fibers was
changed (against the background color) by a process of scorching. This could be produced by an acid burn, or by radiant heat or sufficiently strong radiant light.
The 3D effect is a result of varying distances of the cloth from the radiant energy source. Radiant energy attenuates as the inverse of the square of the distance from the source (1/d^2). At twice the distance, it is 1/4 as intense. at 3 times the distance, it is 1/9 as intense.. at 4 times, 1/16th, and so on. So, more distant areas would be less affected by the radiant energy. That's why I think it's more likely to be caused by some sort of radiant energy than say for instance an acid burn. Acid would have been applied more uniformly, and would not have produced the proper 3D effect.
It's pretty similar in end result to some 3D imaging techniques I've tinkered with over the years. Specifically grayscale bitmaps (or "heightfields"). In grayscale bitmaps, each pixel is represented by a different grayscale level, and each grayscale level represents a different elevation or distance. I've used it to reproduce 3D terrain elevations on maps from grayscale 2D images.
Years ago, there was software available called "basrelief.exe" that claimed to create 3D images from 2D originals, but it had flaws. The 2D image used to create the 3D image had to be directly photographed, and
the flash used. The reason was that the software pulled it's depth information from the intensity of the flash that struck the photographed surface - brighter intensity was interpreted as closer to the camera. Any other lighting, such as ambient light striking the surface from another angle, would distort the 3D result image. About the only way to make it work approximately correctly was to photograph the subject in complete darkness so that only the flash from the camera provided any light for the software to interpret
Grayscale bitmaps are pure height level information presented as an image. White is "higher" or "closer" and black is "lower" or "farther". shades of gray represent varying distances in between - lighter gray closer, darker gray farther. So height levels can be reconstructed and then artificially lit from the side or another angle to bring out the 3D quality of the image. Each pixel has it's own height based upon the intensity of the gray present in it.
I doubt that anyone would have had that experience or information concerning heightfields or grayscale bitmaps in medieval times, and the shroud is at least that old, so how was it produced?
If the shroud were wrapped around an actual body or a statue, the image would have come out distorted as it followed the curves of a body - but it didn't. It came out as if the cloth were held in a flat plane above and below the body (like a film negative in relation to the camera lens), and then "flashed" or "exposed" for lack of a better term.
How on Earth could that happen naturally, or in a process of fakery when such concepts were entirely unknown?
.
The image is faint. Very faint. The images we usually see are contrast-enhanced to bring out the detail of the image, to a more visibly obvious level. The image is so faint that the cloth must be viewed from a distance for the image to be seen at all. When you get too close to it, the faint differences in the fiber colors just merges together into one color or shade of color.
The image is in the "negative", probably due to the method of production. It was not seen as a positive until the photographs of Secundo Pio in the early 1900's. A positive image was seen to occur on the negative plates of his photography sesstion.
The image is ONLY on the surface. The VERY surface. it only goes one fiber deep into the cloth. Not one thread deep, but on FIBER deep on the very surface threads of the weave.
The image was produced by a process of "dehydrative oxidation" - a fancy way of saying burned or scorched. There is no pigment in the image as would be present in a painting. The color of the very surface fibers was
changed (against the background color) by a process of scorching. This could be produced by an acid burn, or by radiant heat or sufficiently strong radiant light.
The 3D effect is a result of varying distances of the cloth from the radiant energy source. Radiant energy attenuates as the inverse of the square of the distance from the source (1/d^2). At twice the distance, it is 1/4 as intense. at 3 times the distance, it is 1/9 as intense.. at 4 times, 1/16th, and so on. So, more distant areas would be less affected by the radiant energy. That's why I think it's more likely to be caused by some sort of radiant energy than say for instance an acid burn. Acid would have been applied more uniformly, and would not have produced the proper 3D effect.
It's pretty similar in end result to some 3D imaging techniques I've tinkered with over the years. Specifically grayscale bitmaps (or "heightfields"). In grayscale bitmaps, each pixel is represented by a different grayscale level, and each grayscale level represents a different elevation or distance. I've used it to reproduce 3D terrain elevations on maps from grayscale 2D images.
Years ago, there was software available called "basrelief.exe" that claimed to create 3D images from 2D originals, but it had flaws. The 2D image used to create the 3D image had to be directly photographed, and
the flash used. The reason was that the software pulled it's depth information from the intensity of the flash that struck the photographed surface - brighter intensity was interpreted as closer to the camera. Any other lighting, such as ambient light striking the surface from another angle, would distort the 3D result image. About the only way to make it work approximately correctly was to photograph the subject in complete darkness so that only the flash from the camera provided any light for the software to interpret
Grayscale bitmaps are pure height level information presented as an image. White is "higher" or "closer" and black is "lower" or "farther". shades of gray represent varying distances in between - lighter gray closer, darker gray farther. So height levels can be reconstructed and then artificially lit from the side or another angle to bring out the 3D quality of the image. Each pixel has it's own height based upon the intensity of the gray present in it.
I doubt that anyone would have had that experience or information concerning heightfields or grayscale bitmaps in medieval times, and the shroud is at least that old, so how was it produced?
If the shroud were wrapped around an actual body or a statue, the image would have come out distorted as it followed the curves of a body - but it didn't. It came out as if the cloth were held in a flat plane above and below the body (like a film negative in relation to the camera lens), and then "flashed" or "exposed" for lack of a better term.
How on Earth could that happen naturally, or in a process of fakery when such concepts were entirely unknown?
.