If you haven’t discovered ShroudScope, now is a good time to check it out.
Despite my three years of professional university training in technical drawing theory and practice back in the early ’60s, I just cannot figure it out at all.
Separately, the frontal and dorsal images in projective geometry jargon are what might be called near-orthogonal projections. If two separate photographs were taken, say on large glass plates, at a scale of one-to-one, the first of the front of the body, and the second of the back of the body, then transferred onto a cloth so that they met at the crown, then the result would be very close to what we see on the Shroud, apart from minor distortions only.
We might be able to account for these minor distortions, because of the way the cloth may have been draped. Close to the edges of the body, the cloth would have fallen away from the horizontal. It could still be sustained at near horizontal, if some of the 100 pound package that Nicodemus brought was packed alongside the body. This could result in a close near-orthogonal image, but only for the two separate aspects.
Because of this near-orthogonality, I have tended to give scant credence to theories involving laminar flow of vapours onto the cloth-surface causing the image. I feel there has to be some kind of significant vertically directed influence in the imaging process. It is one reason why I can be sympathetic to theories such as De Liso’s involving seismic action, variations in the geo-magnetic and electric fields associated with the seismic release of radon gas. These can bring about the necessary vertically directed influence.
However, even this sort of theory breaks down when it comes to the crown of the head, and I cannot resolve it. Essentially there are two distinct ways of bringing the cloth over the head of a body lying on its back.
The first is to maintain the near-horizontal aspect of the cloth over the face and also over the back of the head. There should then be a short section of cloth, clear of the head, on which there is no image, and we would see a gap not less than about 30cm between. There is course no gap seen at all, but the frontal and dorsal images at the crown abut each other.
The second way is to wrap the cloth in near-contact with the hair. However this would cause a major variation in the orthogonality of the image on the cloth, no matter what the imaging process might be, and there would be significant distortion. The only way this can be avoided, is for a spontaneous precise distortion of the cloth at the crown for no explicable reason at the immediate instant of the imaging process, followed by restoration to normality afterwards. This notional distortion of the cloth has to be so precise, that the resulting image retains its orthogonality. I cannot imagine how such a remarkable occurence could possibly come about.
This discontinuity of the image at the crown of the head is an enigma which I suspect has yet to be addressed in a satisfactory way. At present I can see no way of explaining it, apart from my overly imaginative speculation above. I wonder if anyone has looked deeply into this problem before and been able to come up with a better answer.
Can other correspondents see the enigma, or even see a way to a solution?