First, the description of my using “tin man” statues by Mr. Berry is highly misleading. What I did, as discussed in detail in the Journal of Applied Optics 1984, was to first intentionally encode three-dimensional geometric information into a bas relief model. This was accomplished by first mathematically re-scaling the z-coordinate of a given full three-dimensional face so as to suppress its relief. The reason was to try to avoid image blurring that results from a full relief caused by thermal radiation, which is Lambertian in nature. The bas-relief was constructed from a solid bronze casting made from a mold that contained the suppressed relief geometry. This bas-relief was heated uniformly in an oven to a temperature that could scorch linen. As expected, the scorch intensities on the cloth transferred the three-dimensional geometry of the original statue (which had been intentionally transferred to the bas-relief) with seemingly acceptable image blurring (because the cloth-body distances had been significantly suppressed).
The problems with this technique, as explained in detail in my 1984 paper, is that thermal discoloration propagates through the thickness of the cloth on a time scale between 1/100 to 1/10 second. This could be mitigated to some extent by pre-soaking the cloth, but this moved the resulting image to appear more like one of direct contact, owing to the need to vaporize the moisture in the linen which requires time that competes with the thermal penetration time into the cloth. On the Shroud we see a full-sized image of a human form. It seemed to me then — and it still does now — that the concept of placing a linen cloth on a full-sized bas-relief on the extremely short time scales noted above was practically unfeasible and seemingly impossible to a medieval craftsman. The reason for insisting on this requirement is because 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.
There is, however, another problem against using a hot statue or hot bas relief to create a Shroud-like image. The STURP examination showed in several ways that the blood stains occurred physically on the Shroud BEFORE the body image. Blood is considerably more thermally sensitive than cloth. My experiments many years ago showed that whenever one creates a scorch discoloration on cloth, the blood material on that cloth would be unavoidably charred and obliterated by the heat. Since such effects are not at all seen in the blood stains, I have concluded that the hot bas-relief hypothesis is unacceptable.
We must require that ALL characteristics of the Shroud image be explained by any successful image formation hypothesis.