Bitumen of Judea
Encyclopedia
The photographic process
known as Bitumen of Judea is quite possibly the oldest modern photographic
technique. The technique was first used by French lithographer Nicéphore Niépce
in the 1820s. In 1826, using a tarlike material that covered a pewter
plate, he took a picture of the countryside near his home. The process took 42 hours. Normally soluble in oil
s, the bitumen hardened (probably polymerized
) and became insoluble on exposure to light. Coated and exposed copper
plates were thus placed in a solvent
which caused the image to appear, following which the copper was etched
in acid
, forming a printing plate.
Photographic processing
Photographic processing is the chemical means by which photographic film and paper is treated after photographic exposure to produce a negative or positive image...
known as Bitumen of Judea is quite possibly the oldest modern photographic
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...
technique. The technique was first used by French lithographer Nicéphore Niépce
Nicéphore Niépce
Nicéphore Niépce March 7, 1765 – July 5, 1833) was a French inventor, most noted as one of the inventors of photography and a pioneer in the field.He is most noted for producing the world's first known photograph in 1825...
in the 1820s. In 1826, using a tarlike material that covered a pewter
Pewter
Pewter is a malleable metal alloy, traditionally 85–99% tin, with the remainder consisting of copper, antimony, bismuth and lead. Copper and antimony act as hardeners while lead is common in the lower grades of pewter, which have a bluish tint. It has a low melting point, around 170–230 °C ,...
plate, he took a picture of the countryside near his home. The process took 42 hours. Normally soluble in oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
s, the bitumen hardened (probably polymerized
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
) and became insoluble on exposure to light. Coated and exposed copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
plates were thus placed in a solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
which caused the image to appear, following which the copper was etched
Etching
Etching is the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal...
in acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
, forming a printing plate.