Postscript (correction: ‘prescript‘) added July 2019:
You have arrived at a 2014 posting. That was the year in which this investigator finally abandoned the notion of the body image being made by direct scorch off a heated metal template (despite many attractions, like negative image, 3D response etc. But hear later: orchestral DA DA! Yup, still there with the revised technology! DA DA! ).
In its place came two stage image production.
Stage 1: sprinkle white wheaten flour or suchlike vertically onto human subject from head to foot, front and rear (ideally with initial smear of oil to act as weak adhesive). Shake off excess flour, then cover the lightly coated subject with wet linen. Press down VERTICALLY and firmly (thus avoiding sides of subject). Then (and here’s the key step):
Stage 2: suspend the linen horizontally over glowing charcoal embers and roast gently until the desired degree of coloration, thus ‘developing’ the flour imprint, so as to simulate a sweat-generated body image that has become yellowed with centuries of ageing.
The novel two-stage “flour-imprinting’ technology was unveiled initially on my generalist “sciencebuzz” site. (Warning: one has to search assiduously to find it, and it still uses a metal template, albeit unheated, as distinct from human anatomy):
So it’s still thermal development of sorts, but with a key difference. One can take imprints off human anatomy (dead or alive!).
A final wash of the roasted flour imprint with soap and water yields a straw-coloured nebulous image, i.e. with fuzzy, poorly defined edges. It’s still a negative (tone-reversed) image that responds to 3D-rendering software, notably the splendid freely-downloadable ImageJ. (Ring any bells? Better still, orchestral accompaniment – see , correction HEAR earlier – DA DA!))
This 2014 “prescript” replaces the one used for my earlier 2012/2013 postings, deploying abandoned ‘direct scorch’ technology.
Thank you for your patience and forbearance. Here’s where the original posting started:
Original posting starts here:
This posting is prompted by a discussion on Dan Porter’s shroudstory.com site initiated by veteran commentator daveB of Wellington New Zealand.
It began with him claiming that the frontal and dorsal images of the head abutted directly on each other with no gap. He was curious to know how that could have happened.
Well, I did not agree with his observation anyway, and was tempted to provide a link to this graphic below, extracted from the indispensable Shroud Scope.
Note that the discoloured region between the frontal and dorsal heads (central yellow tick) is a water stain, as is clear from the symmetry. Mentally subtract the water stain, and what are you left with? Answer: probably an image free area, ie. gap in common parlance, which rather restricts debate as to the nature of the imaging process, notably imaging of frontal and dorsal surfaces but not sides, and NOT (arguably) the flat of the head either (which is a kind of side).
But I decided against that, wishing to see what other contributors had to say, and loath anyway (for reasons discussed previously) to use that site to voice my opinions and risk attracting the usual snidery, insults and putdowns. This is where I share my ideas – not there.
So I simply asked DaveB to clarify his ideas, and he duly obliged, with useful input from others.
But no one mentioned the symmetry case you see above. Another, more subtle argument was invoked involving the reverse side of the frontal sheet (the one that was concealed from the world’s view by backing Holland cloth until the ‘restoration’ in 2001. Thanks Hugh Farey for tracking down a photograph.
(scroll down to lower of two graphics)
Anyway, everyone now seems agreed that that the two heads are not in direct contact, that there is a space or gap separating the two, and interest is now centred on the length of that gap, relative to the circumference of a human head to see what clues it might offer to body-shroud relationship at the instant of imaging.
Here’s a close up of the area in question:
Already there are hints appearing on the other site that the distance between the frontal and dorsal heads is “just right” in order to correspond with a corpse placed in a shroud that is wrapped up and over the head maintaining close cloth/body contact. There’s a hint too that the evidence for close-wrapping in the authenticity narrative must somehow weaken the anti-authenticity case. Er, not so. If someone set out to simulate the “thought experiment” of a corpse leaving an imprint on an up-and over shroud, he would have taken care to get the distance right (or rather CREDIBLE) in the gap between the two heads. If the gap were too small, observers would have declared it physically impossible for there to be so short a distance of separation. If the gap were made too large, then quite apart from economic considerations (linen is pricey) or practical considerations (a corpse should be a snug fit in its shroud so as not to slide around if moved) there are artistic/aesthetic considerations too: one wants to see a distance of separation that looks “right” and looks “neat” – a kind of Goldilocks zone of visual comfort if you like.
Finally. Hugh Farey mentioned the use that can be made of 3D image-enhancement programs for assisting with image interpretation, with specific mention of ImageJ (used extensively on this site).
So I took the enlared image above of the abutment region of the two heads, and entered into that same ImageJ. Here’s the result. There seems little doubt that there is no image density worth speaking of in the region between frontal and dorsal heads.
Interestingly there may be a hint of ‘wrap-around’ imaging of the otherwise non-imaged top of the head on that right hand dorsal side of the head. That’s a provisional opinion until a wider area has been examined.
Postscript: I have said nothing above as to my preferred mechanism by which the head images were produced (thermal imprinting from a heated bas relief using a particular procedure (“LOTTO”) that results in a faint fuzzy image). But I see from my stats counter that there was a visitor this morning who had clicked on the link to my “scorch” ideas in the wiki entry to the Shroud of Turin (see section headed Image Analysis)
“Shroud researcher Colin Berry has observed that the scorch marks and holes in the shroud also produced clear 3D images under the VP8 analysis. He deduced from this that the shroud image was produced by light scorching, and has produced 3D images from scorches using appropriate software.“
Below that, under the subheading “bas relief” is this passage:
Instead of painting, it has been suggested that the bas-relief could also be heated and used to scorch an image onto the cloth. However researcher Thibault Heimburger performed some experiments with the scorching of linen, and found that a scorch mark is only produced by direct contact with the hot object – thus producing an all-or-nothing discoloration with no graduation of color as is found in the shroud.
I have previously written extended critiques of the Heimburger studies, which incidentally were never ‘covered’ on the Porter site, despite the permanent adverts there on the Home Page to that and another Heimburger paper (commenter-unfriendly pdf formats). The chief criticism was the use of a template with flat planes only, ie. no smooth rounded contours that present to linen at different angles to the normal and thus different impact force per unit area (i.e. fabric-impacting pressure).
Be that as it may, I strongly urge folk to look at the new banner on the top of my Home Page, and note especially the prominence of the nose relative to other features. What price the idea that there is an “all-or-nothing” discoloration with no graduation of colour? What’s more, it’s commonplace to see references in the Shroud literature to the nose especially being more strongly imprinted, which is entirely consistent with (and required of) a bas-relief model, and with fundamental physics too (requiring no recourse to dubious, nay, credulity-stretching radiation models that ask us to accept “orthogonal projection” of unspecified high energy electromagnetic or other radiation.
Postscript: This comment has just appeared from ChrisB: