Hermann Wilhelm Vogel

Not to be confused with Hermann Carl Vogel.
Hermann Wilhelm Vogel

Hermann Wilhelm Vogel, with signature in partial Kurrent handwriting script
Born March 26, 1834
Dobrilugk, Kingdom of Prussia
Died December 17, 1898(1898-12-17) (aged 64)
Berlin, German Empire
Residence Germany
Nationality German
Fields Photochemistry, photography
Institutions Technical University of Berlin
Alma mater University of Berlin
Doctoral advisor Karl Friedrich August Rammelsberg
Doctoral students Alfred Stieglitz

Hermann Wilhelm Vogel (March 26, 1834 – December 17, 1898) [1] was a German photochemist[2] and photographer who discovered dye sensitization, which is of great importance to photography.

Academic career

After finishing school in Frankfurt (Oder), he studied at the Royal Industrial Institute of Berlin, earning his Ph.D. with Karl Friedrich August Rammelsberg in 1863. Vogel's thesis, which was published in Poggendorffs Annalen (119, pp. 497), had the title: Über das Verhalten des Chlorsilbers, Bromsilbers und Iodsilbers im Licht und die Theorie der Photographie (Reactions of Silver Chloride, Silver Bromide and Silver Iodide with Light and the Theory of Photography). This marked the beginning of his research into the photographic process.

From 1860 until 1865, he was an assistant in the mineralogical museum of the University of Berlin, and from 1884 was director of the photo-technical laboratory of the Technical Institute there. From 1864 he was a professor at Berlin's Technische Hochschule (from 1879, the Technical University of Berlin), where he introduced photography as a field of study.

Dye sensitization

In 1873 Vogel discovered dye sensitization,[3] a pivotal contribution to the progress of photography. The photographic emulsions in use at that time were sensitive to blue, violet and ultraviolet light, but only slightly sensitive to green and practically insensitive to the rest of the spectrum. While trying out some factory-made collodion bromide dry plates from England, Vogel was amazed to find that they were more sensitive to green than to blue. He sought the cause and his experiments indicated that this sensitivity was due to a yellow substance in the emulsion, apparently included as an anti-halation agent. Rinsing it out with alcohol removed the unusual sensitivity to green. He then tried adding small amounts of various aniline dyes to freshly prepared emulsions and found several dyes which added sensitivity to various parts of the spectrum, closely corresponding to wavelengths of light the dyes absorbed. Vogel was able to add sensitivity to green, yellow, orange and even red.[4][5][6]

This made photography much more useful to science, allowed a more satisfactory rendering of colored subjects into black-and-white, and brought actual color photography into the realm of the practical.[7]

In the early 1890s, Vogel's son Ernst assisted German-American photographer William Kurtz in applying dye sensitization and three-color photography to halftone printing, so that full-color prints could be economically mass-produced with a printing press.[8]

Other activities

In addition to his work as a photographic technical innovator, Vogel taught Alfred Stieglitz between 1882 and 1886.[9] He participated in at least two photographic expeditions to Egypt as well as others to Italy and possibly Asia.[10] Vogel founded the periodical Photographische Mittheilungen in 1864 and served as its publisher until his death.

His silver tester, photometer for pigment printing and heliotype printing, and universal spectroscope were introduced into general use. He visited the United States in 1870 and 1883.

Publications

Wikisource has original works written by or about:
Hermann Wilhelm Vogel

Notes

  1. ↑ "Photographische Mitteilungen: 1864-1911: A Lasting Legacy to German photochemist Hermann Wilhelm Vogel".
  2. ↑ "Union List of Artist Names, s.v. "Vogel, Hermann Wilhelm"".
  3. ↑ "Dye Sensitization".
  4. ↑ Vogel, H: "On the sensitiveness of bromide of silver to the so-called chemically inactive colours", Chemical News, December 26, 1873:318-319, copying from The Photographic News, date and page not cited but apparently December 12, 1873, in turn translated from Vogel's own publication Photographische Mittheilungen, December, 1873 10(117):233-237.
  5. ↑ Vogel, H: "Photo-spectroscopic researches", The Photographic News, March 20, 1874:136-137, translated from Photographische Mittheilungen, February, 1874 10(119):279-283.
  6. ↑ Vogel, H: "Rendering actinic non-actinic rays", The Photographic News, July 3, 1874:320-321. In this communication, apparently in the original English, Vogel answers critics who suggest that the sensitivity into red which he reports is an error due to an impure spectrum by noting that the Fraunhofer lines recorded on his test plates are in their correct locations, which would not be the case if the photographic action were due to light of other wavelengths. For further details cf. Klaus Hentschel: Mapping the Spectrum, Oxford: OUP, 2002.
  7. ↑  Meldola, R. (October 1874). "Recent Researches in Photography". Popular Science Monthly. 5: 717–720. ISSN 0161-7370, copying from Nature. After summarizing the discoveries of Vogel and Edmond Becquerel, this article notes some of the prospective benefits to science and to photography in general. Caution: an error found in early English-language reports of Becquerel's results with chlorophyll is repeated here. In his original paper in French (Comptes Rendus (1874) 79:185-190) Becquerel reports strong action between Fraunhofer lines C and B (red), not C and D (orange) as it appears in a widely-copied English translation which is reflected here. Subsequent references to these lines in his paper confirm that "C et B" as it appears on page 188 of the original is correct.
  8. ↑ Hirsch, Robert; Erf, Greg (2010-12-28). Exploring Color Photography: From Film to Pixels. Taylor & Francis US. p. 24. ISBN 9780240813356. Retrieved 28 July 2012.
  9. ↑ "Alfred Stieglitz".
  10. ↑ : Mr. J.R. Gossage, Dr. H.W. Vogel (2000). Empire. Nazraeli Press.

References

External links

Herman Wilhelm Vogel (1875) The chemistry of light and photography - Linda Hall Library

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