Hermann Wilhelm Vogel (26 March 1834 – 17 December 1898) was a German photochemist and

photographer A photographer (the Greek φῶς (''phos''), meaning "light", and γραφή (''graphê''), meaning "drawing, writing", together meaning "drawing with light") is a person who uses a camera to make photographs. Duties and types of photograp ...

who discovered dye sensitization, which is of great importance to

photography Photography is the visual arts, art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is empl ...

Academic career

After finishing school in

Frankfurt (Oder) Frankfurt (Oder), also known as Frankfurt an der Oder (, ; Central Marchian: ''Frankfort an de Oder,'' ) is the fourth-largest city in the German state of Brandenburg after Potsdam, Cottbus and Brandenburg an der Havel. With around 58,000 inh ...

, he studied at the Royal Industrial Institute of

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

, earning his Ph.D. with Karl Friedrich August Rammelsberg in 1863. Vogel's thesis, which was published in ''Poggendorffs Annalen'' , 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 Silver iodide is an inorganic compound with the formula Ag I. The compound is a bright yellow solid, but samples almost always contain impurities of metallic silver that give a grey colouration. The silver contamination arises because some samp ...

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 The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

. From 1864 he was a professor at the

Technische Hochschule A ''Technische Hochschule'' (, plural: ''Technische Hochschulen'', abbreviated ''TH'') is a type of university focusing on engineering sciences in Germany. Previously, it also existed in Austria, Switzerland, the Netherlands (), and Finland (, ) ...

in Charlottenburg (today

Technische Universität Berlin (TU Berlin; also known as Berlin Institute of Technology and Technical University of Berlin, although officially the name should not be translated) is a public university, public research university located in Berlin, Germany. It was the first ...

), where he introduced photography as a field of study.Grove Art Online, Vogel, Hermann Wilhelm
/ref> From 1884, he was director of the photo-technical laboratory of TH Charlottenburg.

Dye sensitization

In 1873 Vogel discovered dye sensitization, a pivotal contribution to the progress of

. The

photographic emulsion Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography, it consists of silver halide crystals dispersed in gelatin. The emulsion is usually coated onto a substrate of gla ...

s 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 A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

. While trying out some factory-made

collodion Collodion is a flammable, syrupy solution of nitrocellulose in Diethyl ether, ether and Alcohol (chemistry), alcohol. There are two basic types: flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings ...

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 Aniline (From , meaning ' indigo shrub', and ''-ine'' indicating a derived substance) is an organic compound with the formula . Consisting of a phenyl group () attached to an amino group (), aniline is the simplest aromatic amine. It is an in ...

dye Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...

s 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. This made photography much more useful to science, allowed a more satisfactory rendering of colored subjects into

black-and-white Black-and-white (B&W or B/W) images combine black and white to produce a range of achromatic brightnesses of grey. It is also known as greyscale in technical settings. Media The history of various visual media began with black and white, ...

, and brought actual

color photography Color photography (also spelled as colour photography in English in the Commonwealth of Nations, Commonwealth English) is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray-monochrome ...

into the realm of the practical. In the early 1890s, Vogel's son Ernst assisted German-American photographer William Kurtz in applying dye sensitization and three-color photography to

halftone Halftone is the reprographic technique that simulates continuous tone, continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect.Campbell, Alastair. ''The Designer's Lexicon''. ...

printing, so that full-color prints could be economically mass-produced with a printing press.

Other activities

In addition to his work as a photographic technical innovator, Vogel taught

Alfred Stieglitz Alfred Stieglitz (; January 1, 1864 – July 13, 1946) was an American photographer and modern art promoter who was instrumental over his 50-year career in making photography an accepted art form. In addition to his photography, Stieglitz was k ...

between 1882 and 1886. He participated in at least two photographic expeditions to

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

as well as others to

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

and possibly

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. Vogel founded the periodical ''Photographische Mittheilungen'' in 1864 and served as its publisher until his death. His silver tester,

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

for pigment printing and heliotype printing, and universal spectroscope were introduced into general use. He visited the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

in 1870 and 1883.

Publications

* ''Lehrbuch der Photographie'' (Third edition, Berlin 1878) * ''Praktische Spektralanalyse irdischer Stoffe'' (Second edition, Berlin 1888) * ''Die chemischen Wirkungen des Lichts und die Photographie'' (Second edition, Leipzig 1883) * ''Die Photographie farbiger Gegenstände in den richtigen Tonverhältnissen'' (Berlin 1885) * ''Vom Indischen Ozean bis zum Goldland'' Reisebeobachtungen (Berlin 1878) * ''Lichtbilder nach der Natur'' (Berlin 1879) * ''The Chemistry of Light and Photography, in Their Application to Art, Science, and Industry'' (New and thoroughly revised edition, D. Appleton, New York 1889) * ''Über das Spiritistentreiben'' (Berlin 1880)

Notes

References

External links

* Herman Wilhelm Vogel (1875
''The chemistry of light and photography''
- Linda Hall Library *
A Simple Test For Carbonic Oxide
,

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...

article on carbon monoxide detection developed by Vogel, 23 June 1877, p. 386 {{DEFAULTSORT:Vogel, Hermann Wilhelm 1834 births 1898 deaths Chemists from the Kingdom of Prussia People from Doberlug-Kirchhain 19th-century German chemists Photographers from Brandenburg People from the Province of Brandenburg Humboldt University of Berlin alumni Academic staff of Technische Universität Berlin