Just check it out. You’ll be intrigued by it.
Sorry, Jmacusa, I am fully aware of the camera obscura theories and the Lynn Picknett and Clive Prince theory that Leonardo da Vinci created the Shroud. There is NO possibility that I will be "intrigued" by it because it is an impossibility once you understand the science behind the camera obscura and what is known of the image formation chemistry, physics, and history of the Shroud.
As I told you in my previous post the Shroud is NOT a photograph. It only bears a superficial resemblance to a photograph. Nor is it a painting.
Further reasons:
Both photographs and paintings would require a residue of either a optically alterable fixable chemical or an applied pigment of which the image is composed; the Shroud has neither on its surface nor imbued into its threads or fibers. In fact, there is no residue of any every having been applied down to the limits of electron microscopic examination. . . and it has been examined down to the molecular level. Electron-microscopic spectrometry shows no residue of applied chemicals or pigments. THAT is definitive.
In addition, the image DOES NOT exist under the blood stains, indicating the blood stains pre-existed the formation of the image. Since many of the blood stains require registration with body parts, this precludes a camera obscura method of creation where the blood stains would be logically applied post image creation.
We DO now know of what the image is composed. It exists in the exceedingly thin layer of the soapwort starch in which the Flax was fullered (washed and bleached) in before it was even woven into the Shroud form. We know this layer was done before weaving because of pattern in the cloth that shows the use of hank bleaching. This layer is just 70-100Å (Angstroms) thick on just the surface of the fibers, about the thickness of a soap bubble.
The image exists on the ephemeral surface in a sugary caramel like substance formed by a Maillard browning reaction similar to that which causes bread to brown. We do not know why one portion of the starch made this conversion forming the image, while another portion right next to it did not. Heat, electricity, chemical reaction, and/or age, or a combination of any can cause Maillard reactions in any carbohydrate based substance such as this soapwort coating and as time passes the rest will brown and will eventually match the image, causing the image to fade to nothingness. This is why older natural cloth turn brown with age.
Fire can cause a rapid Maillard reaction. . . this can be seen around the scorch marks on the Shroud from the fire of 1535—but leaves a distinctive signature under Ultra-violet light. Chemical Reaction Maillard reactions will leave residues of the chemicals that cause the reaction. These are not present.
The late Raymond N. Rogers, the Pyrolysis Chemist who proposed the Maillard hypothesis in a peer-reviewed and duplicated study, explains the findings". You should find this REAL science far more intriguing than Lynn Picknett's and Clive Prince's fake scholarship about Camera Obscuras and Leonardo da Vinci creating the Shroud.
By the way, the camera obscure was known in antiquity far predating even da Vinci's era. . . with mention in literature as early as 1000 AD, and there is evidence the Roman's had such rooms for tracing art. However, the ability to concentrate light over long periods of time onto a single area necessary to FIX and burn an image into a photograph, that was a technology that was not mentioned in literature anywhere until the 19th century.