Monochromatic tube excited microXRF of Daguerreotypes Valentina Ljubić Tobisch(1), Dieter Ingerle(1), Peter Wobrauschek(2), Christina Streli(1,2), Karin Whitmore(3), Klaudia Hradil(1) (1) Technische Universität Wien, X-Ray Center, Getreidemarkt 9, 1060 Vienna, Austria (2) Technische Universität Wien, Atominstitut: Stadionallee 2, 1020 Vienna, Austria (3) Technische Universität Wien, USTEM, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria The publication of the photographic process based on the method of Louis-Jacques-Mandé Daguerre on August 19, 1839 is considered the birth of photography. Initially, the process could only be used to depict landscapes due to the lack of technical equipment and long exposure times. However, a number of technical advances, which were developed in Vienna in the early years in particular, led to serious improvements in the quality of the phototypes but also to a shortening of the exposure time. These improvements also enabled the first portraits to be taken and the development of family photography. The daguerreotype method was based on the photosensitivity of halides Br, Cl and I on a silver-plated copper support plate. In a final finishing step, the plates were often gilded. As part of the Heritage Science project PHELETYPIA [3], the surface morphology and elemental composition of historical daguerreotypes from museum collections are being analyzed. The results should provide information about the manufacturing processes as well as the ageing phenomena in relation to the long-term preservation of these extremely sensitive artefacts. Two daguerreotypes from the collection of the State Museum in Varaždin, Croatia, were analyzed for the spatial distribution of the main elements Au, Ag and Hg using a monochromatic tube excited micro X-ray fluorescence spectrometer (XRF) [1]. Applications of imaging techniques with a microbeam on daguerreotypes have already been tested several times with synchrotron radiation [2]. This work compares two different results, where on the one hand the Hg-L and on the other hand the Au-L serve as the main imaging information source. 1 Ingerle D, Swies J, Iro M, Wobrauschek P, Streli C, Hradil K (2020) A monochromatic confocal micro-x-ray fluorescence (μXRF) spectrometer for the lab. Rev Sci Instrum 91:1–8. doi: doi.org/10.1063/5.0028830 2 Kozachuk MS, Sham T-K, Martin RR, Nelson AJ, Coulthard I, Smieska L, Woll AR (2019) Recovering Past Reflections: X-ray Fluorescence Imaging of Electrocleaned 19th Century Daguerreotypes. Heritage 2:568–586. doi: doi.org/10.3390/heritage2010037 3 Ljubic Tobisch V, Artaker A, Kautek W (2023) PHELETYPIA. Proj. PHELETYPIA “The impact early Photogr. electrotyping media Creat. images Contemp. art" (Heritage 2020-060 PHELETYPIA) by Herit. Sci. Austria grant Progr. Austrian Acad. Sci.