page_title: Johann Pucher
section_title: Hyalotype process
hierarchical_section_title: Johann Pucher / Hyalotype process
caption_attribution_description: Self-portrait (original) Slovenščina: Avtoportret, fotografija na steklo, 12X10 cm, Narodni muzej Slovenije.
context_page_description: Johann Augustin Pucher was a Slovene priest, scientist, photographer, artist, and poet who invented an unusual process for making photographs on glass.
  Although his were not the first glass photographs, Pucher's process was unique. It was the only 19th-century photography technique that was not based on expensive silver halide chemistry but was still sensitive enough to use in a camera, with exposure times comparable to those of the daguerreotype and calotype. Modern testing of Pucher's photographs has confirmed their chemically unusual nature. However, his process was never commercialized, and attempts to recreate it based on published information have been unsuccessful.
context_section_description: According to Pucher's records of his photographic process, he coated a small glass plate with a layer of light-sensitive sulfur, exposed it to iodine vapors, and inserted the prepared plate into a camera. He then poured mercury into a metal container, placed the mercury at the bottom of the camera, and heated it from below. He exposed the prepared plate to light for 15 seconds, and mercury vapors coated the exposed places on the picture. Pucher strengthened the picture with bromine steam and fixed it by wrapping it with alcohol. Finally, he preserved the photo with varnish.
  The advantages of Pucher's procedure included a shorter exposure time (15 seconds, which allowed him to make portraits), a positive image, and the possibility of reproduction.
  Pucher was not the first to try to create photos on glass: A Frenchman, Abel Niépce de Saint-Victor, reported his own invention to the French Academy of Sciences in 1847. It was not until January 1851 that the Austrian Academy of Sciences published a report on Pucher's method.
caption: Hyalotype with self-portrait by Johann Pucher
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