Is it true that the Shroud image (“unlike a scorch”) ceases to be visible when backlit and viewed with transmitted light? A reader comments…

Here’s a comment I received from Adrie this morning, which I reproduce in full with his permission. It concerns the oft-cited claim that the Shroud image cannot be seen in transmitted light, i.e. with the light source behind, as  discovered and reported by STURP’s Official Reporting Photographer (Barrie Schwortz). Adrie has provided two links to that finding. Both show on my screen as tiny pictures in the centre of the screen.

Er, yes, well….

However, that has not deterred your intrepid seeker after truth from enlarging, and adjusting contrast and brightness.

I’ll show Adrie’ s comment first, then my editing of the Schwortz photographs (copyright acknowledged, shown here for research purposes, fair use etc). I’ll save my own interpretation for later.

Adrie says:

Yes, I agree with you that the stars may be just an artefact of the decorator’s cloth. And you’re right about the difficulty in discerning the image in low magnification as well.
These are the backlit photos of the Shroud (by “macroscopic scale” I meant ‘visible to the naked eye’). They show that some parts of the image are a bit darker than the background, for instance the abdomen and ventral thighs, but nowhere in the body image the net effect of oxidation+stars is a lighter image than the background, except perhaps at the four areas at the forehead, beneath a ventral knee, at the back of the head and next to a dorsal foot. But these lighter areas don’t constitute an image and seem to be artefacts of the light sources or wear. The book “The Orphaned Manuscript” has the backlit photo of the ventral side. It shows white borders around the burn patches and some white lines along the scorched longitudinal folds that are not visible in the online photo.

I wonder if the back of the cloth was lighted uniformly. If the middle strip of the cloth received more backlight than the sides (and if the top and bottom parts of the image received more than the middle part of it), this might explain (at least partly) why the image is less visible than the light scorches and why only the middle part of the ventral image is visible.
Adler said “In reflectance photographs the images of the waterstains, scorches, blood, and body images are all approximately of about the same intensity.” The text then has the two sentences about disappearance of the body image and the presence of the other marks in transmitted light (already quoted), and then follows a cryptic sentence: “In the reflectance mode the colored body image fibers produce 100% of the reflected radiation recorded, but in the transmitted mode they only contribute about 1% of the radiation recorded, thus demonstrating their superficial one-fiber-deep nature.” (Adler, Chemical and Physical aspects, p. 17). Pellicori wrote: “Figure 2 presents reflectances relative to background and normalized to ~1.0 at 700 nm for body image areas, scorches from the year 1532 fire, and bloodstained areas. […] A representative light scorch and a body stain have nearly the same color” (Spectral properties, p. 1915). Pellicori doesn’t discuss transmitted mode recordings of the Shroud, so perhaps the details, especially the (backlight-corrected) percentages for the light scorches, are in another STURP article, which I haven’t got…
John Jackson recently said “the STURP examination clearly showed that the body image is only on the surface of the cloth, whereas the 1532 scorch mark discolorations at the same intensity of the body image discolor the cloth throughout its bulk.” link

Antonacci Rogers probed the Shroud with a dissecting needle under a microscope and testified to “the discontinuous nature of the color and the extremely shallow penetration of the color into the cloth” ( p. 12). I don’t know if anyone ever did this with a representative light scorch. BTW, in 1982 Rogers and Schwalbe wrote “With properly controlled heat and timing, superficial scorches can be produced on cloth without affecting the gross mechanical properties of the fabric” (Physics and Chemistry, p. 25).

Thanks Adrie. There’s a lot of interesting detail there. Forgive me if I think for a day or two before commenting directly. Now for those pictures:

Schwortz image from first link above, after enlargement, and then adjustment of brightness and contrast. (MS Picture Manager: Brightness/Contrast/Midrange value: 34,67,43 respectively)

Questions: Firstly: Is it just the bloodstains on the forearms that make them visible, or is there body image there too. Are the thighs not visible too (see Adrie’s reference to thighs above) ?

Here’s a close up of those forearms. with the corresponding region from the Shroud Scope image (without further photo-editing on my part) for comparison.

Shroud Scope left, cropped forearms from previous picture right. Note the way that banding and its associated colour has become  accentuated on the right hand image, possibly at the expense of body image.

New addition: 14:20:

Now for a similar comparison involving the upper dorsal region, chosen because it has many prominent scourge marks, which are of course blood (not body image):

The ‘blood belt’ at bottom of picture shows in both, but for some reason the scourge marks which are so apparent on the Shroud Scope image (left) do not appear to be present on the right,. Instead one has a series of horizontal marks (banding?).

If the backlighting fails to show the scourge marks,  appearing instead to emphasise banding in the linen, then notwithstanding that it shows the major 1532 burn holes and their borders,  it is perhaps hardly surprising that the faint body image is scarcely to be seen. Well, that’s my preliminary view, but I shall go on comparing images from the two sources to see if the above discrepancy is a general one or not.

Update: 14:40

Should anyone be wondering why the visibility of the Shroud by transmitted light is so crucial a question, see the first comment below that appeared recently on the site:

As for that second comment, I am now able to oblige, with this link to yesterday’s post, with further links to a 3  instalment response  to Thibault Heimburger’s critique of the scorching hypothesis.  There – two birds with one stone…

New addition: 15:45:

Yup, the legs seem to be there,especially the one on the viewer’s right, (just)  even in the watermark region…


The Shroud graphics displayed here are hopelessly inadequate, needless to say, and I would be the first to acknowledge that. They are enlargements of thumbnail pictures in a gallery that was clearly not intended for cut-and-paste merchants like myself.  😉

But if I do not get to see the full-size picture, or more importantly, permission to publish it, then how likely is it that others have seen it  – like that commentator above who believes that Barrie Schwortz’s picture “proves” the Shroud image is not a scorch. Might I suggest a moratorium on such comments unless-  or until -the full-size pictures are available for us all to see and interpret? Having said that, and trying  very hard to keep an open mind, I very much doubt, from looking at the comparisons with Shroud Scope above, that Barrie Schwortz has/had an open-and-shut case on the Shroud image being something other than a scorch, based purely on his back-lighting evidence. To make a comparison with the 1532 scorch marks as if the latter were typical scorches (if indeed there is such a thing)  without knowing the precise conditions under which they were formed in that sealed silver reliquary  (aerobic? partially aerobic? anaerobic etc? full width? partial width? superficial only?) is of questionable legitimacy anyway. There should arguably have been some tests done with modern experimental scorches – faint and superficial ones especially – under the same lighting conditions.


Late addition – prompted by Hugh’s comment (just in) re the method of back-lighting:

Comparison of Shroud Scope and B.Schwortz image, dorsal side, head region. Is that a single spot we see on the right?



Comments welcome.


About Colin Berry

Retired science bod, previous research interests: phototherapy of neonatal jaundice, membrane influences on microsomal UDP-glucuronyltransferase, defective bilirubin and xenobiotic conjugation and hepatic excretion, dietary fibre and resistant starch.
This entry was posted in Shroud of Turin and tagged , , , . Bookmark the permalink.

3 Responses to Is it true that the Shroud image (“unlike a scorch”) ceases to be visible when backlit and viewed with transmitted light? A reader comments…

  1. Hugh Farey says:

    Are we looking at much more than noise, I wonder? The method of backlighting the shroud was almost certainly extremely crude. Is it not the case that only a very small section of the seam connecting the backing cloth to the shroud was unpicked, in which case it would have been difficult to insert anything like a uniform lighting unit between shroud and backing, or was the light behind both shroud and backing cloth together? Do we know? If the latter, and some kind of light-box was used, how uniform was the light? Without this information I’m not sure the appearance/non-appearance of the image is in any way significant; it doesn’t even indicate or contra-indicate any method of achieving it, let alone prove anything.

  2. colinsberry says:

    Hello Hugh

    Prompted by your comment, I’ve just added another picture on the end of my posting. One gets the impression that there is a single bright spot that is illuminating the dorsal side from behind. That may be OK for illustrative photography, but can hardly be a basis on which to base a major claim re one kind of image being different from another.

    Even if the lighting had been ideal, I would still have grave reservations about the kind of argument/logic that says: the 1532 scorch marks do this, the body image does that, therefore the body image cannot be a scorch. The body image might not be scorch (if not then what?) but one needs more robust evidence than the above upon which to dismiss it.

    The key feature of the body image has surely to be that is is a light/dark reversed image. That unusual and crucial characteristic is explained as a thermal imprint from a hot template. Until Barrie Schwortz and others can provide an alternative explanation for that negative image with robust evidence, then I for one am sticking with the scorch hypothesis …

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