Hermann W. Vogel
Encyclopedia
Hermann Wilhelm Vogel was a German
photochemist
and photographer who made a key discovery of great importance to photography
.
, 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 in 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.
In 1873 Vogel discovered dye sensitization, a pivotal contribution to the progress of photography
. The photographic emulsion
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
. While trying out some factory-made collodion
bromide
dry plate
s 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
dye
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
, and brought actual color photography
into the realm of the practical.
between 1882 and 1886. He participated in at least two photographic expeditions to Egypt as well as others to Italy and possibly Asia. 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 twice visited the United States
(1870, 1883).
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
photochemist
Photochemistry
Photochemistry, a sub-discipline of chemistry, is the study of chemical reactions that proceed with the absorption of light by atoms or molecules.. Everyday examples include photosynthesis, the degradation of plastics and the formation of vitamin D with sunlight.-Principles:Light is a type of...
and photographer who made a key discovery of great importance to photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
.
Academic career
After finishing school in Frankfurt (Oder)Frankfurt (Oder)
Frankfurt is a town in Brandenburg, Germany, located on the Oder River, on the German-Polish border directly opposite the town of Słubice which was a part of Frankfurt until 1945. At the end of the 1980s it reached a population peak with more than 87,000 inhabitants...
, he studied at the Royal Industrial Institute of Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
, earning his Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
with Karl Friedrich August Rammelsberg
Karl Friedrich August Rammelsberg
Karl Friedrich August Rammelsberg was a German mineralogist from Berlin, Prussia.He was educated for the medical profession and graduated in 1837 at Berlin University. In 1841 he became privatdozent in the university, and in 1845 professor extraordinary of chemistry...
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 chloride
Silver chloride is a chemical compound with the chemical formula AgCl. This white crystalline solid is well known for its low solubility in water . Upon illumination or heating, silver chloride converts to silver , which is signalled by greyish or purplish coloration to some samples...
, Silver Bromide
Silver bromide
Silver bromide , a soft, pale-yellow, water insoluble salt well known for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials. AgBr is widely used in photographic films and is believed by some to have been used for making...
and Silver Iodide
Silver iodide
Silver iodide is a yellow, inorganic, photosensitive iodide of silver used in photography, in medicine as an antiseptic, and in rainmaking for cloud seeding.-Crystal structure:...
with Light and the Theory of Photography). This marked the beginning of his research in the photographic process.
From 1860 until 1865, he was an assistant in the mineralogical museum of the University of Berlin
Humboldt University of Berlin
The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...
, 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
Technische Hochschule
Technische Hochschule is what an Institute of Technology used to be called in German-speaking countries, as well as in the Netherlands, before most of them changed their name to Technische Universität or Technische Universiteit in the 1970s and in the...
(from 1879, the Technical University of Berlin
Technical University of Berlin
The Technische Universität Berlin is a research university located in Berlin, Germany. Translating the name into English is discouraged by the university, however paraphrasing as Berlin Institute of Technology is recommended by the university if necessary .The TU Berlin was founded...
), where he introduced photography as a field of study.
Dye sensitization
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
. The photographic emulsion
Photographic emulsion
Photographic emulsion is a light-sensitive colloid, such as gelatin, coated onto a substrate. In silver-gelatin photography, the emulsion consists of silver halide crystals suspended in gelatin, and the substrate may be glass, plastic film, paper or fabric....
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
Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...
. While trying out some factory-made collodion
Collodion
Collodion is a flammable, syrupy solution of pyroxylin in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...
bromide
Silver bromide
Silver bromide , a soft, pale-yellow, water insoluble salt well known for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials. AgBr is widely used in photographic films and is believed by some to have been used for making...
dry plate
Dry plate
Dry plate, also known as gelatin process, is an improved type of photographic plate. It was invented by Dr. Richard L. Maddox in 1871, and by 1879 it was so well introduced that the first dry plate factory had been established...
s 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
Anti-halation backing
An anti-halation backing is a layer found in most photographic films. It is usually a coating on the back of the film base, but sometimes it is incorporated between the light-sensitive emulsion and the base. The light that passes through the emulsion is absorbed by the anti-halation layer...
agent. Rinsing it out with alcohol removed the unusual sensitivity to green. He then tried adding small amounts of various aniline
Aniline
Aniline, phenylamine or aminobenzene is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Being a precursor to many industrial chemicals, its main use is in the manufacture of precursors to polyurethane...
dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
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
Black-and-white, often abbreviated B/W or B&W, is a term referring to a number of monochrome forms in visual arts.Black-and-white as a description is also something of a misnomer, for in addition to black and white, most of these media included varying shades of gray...
, and brought actual color photography
Color photography
Color photography is photography that uses media capable of representing colors, which are traditionally produced chemically during the photographic processing phase...
into the realm of the practical.
Other activities
In addition to his work as a photographic technical innovator, Vogel taught Alfred StieglitzAlfred Stieglitz
Alfred Stieglitz was an American photographer and modern art promoter who was instrumental over his fifty-year career in making photography an accepted art form...
between 1882 and 1886. He participated in at least two photographic expeditions to Egypt as well as others to Italy and possibly Asia. Vogel founded the periodical Photographische Mittheilungen in 1864 and served as its publisher until his death.
His silver tester, photometer
Photometer
In its widest sense, a photometer is an instrument for measuring light intensity or optical properties of solutions or surfaces. Photometers are used to measure:*Illuminance*Irradiance*Light absorption*Scattering of light*Reflection of light*Fluorescence...
for pigment printing and heliotype printing, and universal spectroscope were introduced into general use. He twice visited the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
(1870, 1883).
Publications
- Lehrbuch der Photographie (3. Aufl., Berlin 1878);
- Praktische Spektralanalyse irdischer Stoffe (2. Aufl., Berlin 1888 ff.);
- Die chemischen Wirkungen des Lichts und die Photographie (2. Aufl., 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)
- Über das Spiritistentreiben (Berlin 1880)