This work compares the luminance level of photographs of the face on the Turin Shroud with other experiments. Luminance levels are analyzed in order to extract 3D information. Comparisons may aid in better understanding of how the image formed. Four significant photographs of faces are analyzed by a new technique to correlate the black-and-white luminance of various photographic images with the image on the Shroud. Three photographs of the facial image were used to verify the stability of the results, according to variations in the photographic characteristics of the same subject. After normalization of each digitized image, areas corresponding to various classes of gray were highlighted, in correlate them with 3D information on the distance between face and Shroud. All the photographs except that of the “Edessa Mandylion” show some 3D characteristics and the Shroud photographs, although disturbed by many defects, seem to correlate well with the sheet-face distance. Perhaps the best 3D results are those yielded by the carbon dust technique proposed by E. A. Craig, although it presents many open questions regarding formation mechanisms. With respect to the photographs of the Shroud, the experiments of V. Pesce Delfino and J. Nickell show a much higher percentage of saturated pixels correlated with areas of non-contact between face and Shroud. This fact is in contrast with the hypothesis that the body image of the Shroud formed according to the technique proposed by the above researchers.