The only person who has found vermillion (HgS) and red ochre on the Shroud in sufficient quantities to rise to visibility, even under a microscope, is Dr. Walter C. McCrone, who claims to have seen "large quantities" of both pigments on the shroud image areas, and who refused to submit his work for peer review. No other microscopist, using both visible light and electron microscopy, have found such quantities. While they did find small amounts of both red ochre and vermillion, they were randomly distributed over the Shroud with no concentration in any image areas.
McCrone claimed that the blood was vermillion because of eyeballing it in a visible light microscope... however, much more sophisticated tests done by world renowned specialists in blood chemistries and hemoglobins and porphyrins their decendent compounds, who reported their findings in peer reviewed scientific journals, have found that it is indeed blood remnants... in fact, human blood remnants.
"Dr. Alan Adler, an expert on porphyrins, the types of colored compounds seen in blood, chlorophyll, and many other natural products concluded that the blood is real. In collaboration with Dr. John Heller [an expert on Medical Physics] the conclusions that the blood is real was published in the peer-reviewed scientific journal Applied Optics [19, (16) 1980]. The heme was converted into its parent porphyrin, and this was confirmed with spectral analysis.Heller and Adler concluded that it was actual blood material on the basis of physics and chemistry based testing, including:
Baima Bollone also found both the heme porphyrin ring of blood and the globulin in flakes of blood from Shroud samples, independently confirming the work of Adler and Heller.
In addition, the x-ray-fluorescence spectra showed excess iron in blood areas, as expected for blood. Microchemical tests for proteins were positive in blood areas but not in any other parts of the Shroud.
...but it is very crude, requiring much fudging and a number of blatant, scientifically-impermissible "corrections" to produce anything resembling a human face and body
Actually, you don't. I've done it myself... and it does NOT require fudging. The original VP-8 Image analyzer did not even allow such manipulation.
Joe Nickell was the first person to suggest this method of producing the Shroud. He observed that contact imprints from bodies are invariably grossly distorted, and hypotheses involving a vapor or radiation would cause the image to penetrate the cloth, unlike the superficial Shroud image that is observed. After experimenting with various techniques, the Shroud artist prepared a suitable mixture of pigments and tempera binder, molded a wet linen sheet over the bas-relief he had constructed, and used a dauber (also termed a pounce or tamper) to apply the mixture to the surface of the linen.Again, there are NO pigments or binders on the Shroud creating the image.
As for Joe Nickell being the first to suggest the bas-relief rubbing technique, he isn't. It was suggested and tried before he was born.
But let me assert that ad hoc, overreaching, counter-arguments to McCrone's conclusions--such as (1) some of the iron oxide particles came from blood iron, (2) most of the red particulate matter is from the blood on the Shroud, (3) most of the red particulate matter is "intimately associated with the image areas because shards of this material have broken off the blood areas and, since image area is always folded against image area, there occurred a translocation of the shards from the blood areas to the non-blood image areas," and (4) the presence of pigment particles on the shroud is due to paint chips falling off the frescoed ceiling and walls of the room use for the Shroud examination--are so far beyond the pale that they are a mockery of analytical thinking. Such explanations are pseudoscientific attempts to keep the possibility of authenticity alive in the minds of supporters who lack the ability to think critically. There is no blood on the Shroud: all the forensic tests specific for blood have failed18 (although some investigators19 unrigorously concluded that blood was present after conducting numerous forensic tests for iron, protein, albumin, etc., which came up positive because these materials are indeed on the Shroud in the form of tempera paint). Old blood is not bright red, and no amount of bilirubin20 can explain that away. Real blood mats on hair, and does not form perfect rivulets and spiral flows. Real blood does not contain red ochre, vermilion, and alizarin red pigments. Real blood and its organic derivatives have refractive indices much less than red ochre or vermilion, and they can be easily distinguished using Becke line movement under a light microscope. McCrone's examination of the red particles on the Shroud samples revealed no blood or blood derivatives.
http://www.freeinquiry.com/skeptic/shroud/as/schafersman.html
The STURP scientists find no pigment particles at 20-50x (I used 400-2500x). They find no cementation of the fibers nor evidence of capillary flow. There is no way, at 50x, that anyone could recongnize the red particles as Fe2O3 and as red ochre or the HgS as a ninth century vermilion, and no way anyone could see that the pigment particles are cemented into an organic matrix and to the fibers. The amounts of pigments and medium on the body-image areas and some of the blood-image areas, barely visible microscopically, demonstrate that the absorption spectroscopy on 1-cm2 areas by Pellicori9 and others could not have detected them. Heller and Adler10 acknowledge the existence of Fe2O3 and Hgs in blood image areas
http://www.freeinquiry.com/skeptic/shroud/as/mccrone.html