In the second period (1969-1988) the tissue and image study through exams and analysis made directly on the Shroud was added to previous methodologies (never abandoned) and different kinds of samples were taken as well. This was possible thank to new knowledge and technologies, mainly in the physics, chemistry, biology and legal medicine fields. In total, there were four analysis and sampling campaigns: in 1969, 1973, 1978 and 1988.
Whereas the 1969 studies and samplings did not provide satisfactory results, in 1973 samplings of a tissue specimen and of flower plants pollen grains enabled to better know the tissue characteristics and, most of all, to consider the Shrouds long lasting presence not only in Europe but also in the palestinian and anatolian regions highly probable due to the discovering on it of pollen grains of species from those areas.
The most important direct Shroud research decidedly was the one that started at the end of the 1978 exposition when, from october 8 to 13, it was examined by an international team of 44 scientists who made a series of examinations and samplings for 120 hours in total. The results of these examinations undoubtedly are the base of modern Shroud research. The study of samples taken from the so called "hematic areas" of the Shroud proved it is human blood of the AB group.
The image examination, through modern equipements, enabled to undeniably prove the lack of pigments and dyes on the cloth and the fact that there is no body image under the bloodstains (and therefore it formed afterwards) and that it is caused by a dehydrating oxidation of the tissue superficial fibres cellulose by a still unknown and certainly not artificial process.
However, the use of photography as a survey tool did not lose importance. An evident proof of this is the new research field rising from the application of computer techniques to the study of the Shroud. From 1977 a processing of all the Shroud images was performed: among other things, it was discovered that it has tridimensional characteristics niether paintings nor normal pictures have and many otherwise invisible details like, for example, some traces on the right eyelid left by an object that could very likely be identified, on the basis of specific characters, as a first half of the I century a.C. Roman coin, brought out.
Moreover, theoretical and experimental research on image formation continued and, repeatedly among others, some theories on the Shroud being an artefact realized through pictorial methods or thermic energy generated by a heated mould took form; these theories, even if interesting, lack on the experimental point of view because either they are not sustained by experiments or these proofs lead to images that have physical-chemical characteristics very different from the Shroud image ones.
The last research campaign was in 1988 when, after a nearly two years elaborate and animated preparation, some tissue samples that were removed from the Shroud for carbon 14 dating indicated an origin date between 1260 and 1390 a.C. These issues were argued out in the following years and still are argued by experts about carbon 14 dating reliability in dating an object with historical and so distinctive chemical-physical characteristics as the Shroud has.
Some experimental studies have further reopened the scientific debate on tissue dating with results that seem to prove a possible and considerable chemical and biological contamination that therefore makes the realization of a wide research and new surveys program indispensable to study the issue of introducing an appropriate correction element to that radiocarbon date.