Scatigno Claudia, Teodonio Lorenzo, Di Rocco Eugenia, Festa Giulia
CREF-Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Via Panisperna 89a c/o P.za del Viminale 1, 00184 Roma, Italy.
Freelance Restorer CRAF-Centro di Ricerca e Archiviazione della Fotografia, Piazza Castello, 33097 Spilimbergo, Italy.
Polymers (Basel). 2024 Jun 28;16(13):1850. doi: 10.3390/polym16131850.
Up to the 1930s, the Italian pictorialism movement dominated photography, and many handcrafted procedures started appearing. Each operator had his own working method and his own secrets to create special effects that moved away from the standard processes. Here, a methodology that combines X-ray fluorescence and infrared analysis spectroscopy with unsupervised learning techniques was developed on an unconventional Italian photographic print collection (the Piero Vanni Collection, 1889-1939) to unveil the artistic technique by the extraction of spectroscopic benchmarks. The methodology allowed the distinction of hidden elements, such as iodine and manganese in silver halide printing, or highlighted slight differences in the same printing technique and unveiled the stylistic practice. Spectroscopic benchmarks were extracted to identify the elemental and molecular fingerprint layers, as the oil-based prints were obscured by the proteinaceous binder. It was identified that the pigments used were silicates or iron oxide introduced into the solution or that they retraced the practice of reusing materials to produce completely different printing techniques. In general, four main groups were extracted, in this way recreating the 'artistic palette' of the unconventional photography of the artist. The four groups were the following: (1) Cr, Fe, K, potassium dichromate, and gum arabic bands characterized the dichromate salts; (2) Ag, Ba, Sr, Mn, Fe, S, Ba, gelatin, and albumen characterized the silver halide emulsions on the baryta layer; (3) the carbon prints were benchmarked by K, Cr, dichromate salts, and pigmented gelatin; and (4) the heterogeneous class of bromoil prints was characterized by Ba, Fe, Cr, Ca, K, Ag, Si, dichromate salts, and iron-based pigments. Some exceptions were found, such as the baryta layer being divided into gum bichromate groups or the use of albumen in silver particles suspended in gelatin, to underline the unconventional photography at the end of the 10th century.
直到20世纪30年代，意大利画意摄影运动主导着摄影领域，许多手工制作程序开始出现。每个操作者都有自己的工作方法和创造特殊效果的秘诀，这些效果偏离了标准流程。在此，针对一批非传统的意大利摄影冲印品收藏（皮耶罗·万尼收藏，1889 - 1939年），开发了一种将X射线荧光和红外分析光谱与无监督学习技术相结合的方法，通过提取光谱基准来揭示其艺术技巧。该方法能够区分隐藏元素，如卤化银冲印中的碘和锰，或突出同一冲印技术中的细微差异，并揭示风格实践。由于油基冲印品被蛋白质粘合剂遮盖，提取了光谱基准以识别元素和分子指纹层。经鉴定，所使用的颜料是引入溶液中的硅酸盐或氧化铁，或者他们追溯了重新利用材料以产生完全不同冲印技术的做法。总体而言，提取了四个主要类别，从而重现了这位艺术家非传统摄影的“艺术调色板”。这四个类别如下：(1) 铬、铁、钾、重铬酸钾和阿拉伯树胶带表征重铬酸盐；(2) 银、钡、锶、锰、铁、硫、钡、明胶和蛋白表征钡层上的卤化银乳剂；(3) 碳冲印品以钾、铬、重铬酸盐和有色明胶为基准；(4) 溴油冲印品的异质类别以钡、铁、铬、钙、钾、银、硅、重铬酸盐和铁基颜料为特征。发现了一些例外情况，例如钡层被分为重铬酸胶类别，或者在悬浮于明胶中的银颗粒中使用蛋白，以突出19世纪末的非传统摄影。
