Ambrotype (1855–70): Process
that creates a positive image on glass using collodion.
It was invented in the United States in 1854 by James
Ambrose Cutting and used until 1880.
Analog (image): In photography, a
portrayal of reality obtained by imprinting light on
a sensitive plate, one image at a time. In television
and video, the result of a graphical analysis that is
represented via an electronic beam sweeping a screen,
allowing black-and-white or colour masses to be reproduced
on a cathode-ray screen.
Backlit: Said of
a photograph taken toward the light source, rather away
from it, as is sometimes recommended to beginners.
Autochrome: The first colour process,
invented by the Lumière brothers. It was a great
commercial success between 1907 and 1930. A glass plate
is covered with a layer of potato starch dyed violet
blue, orange-red, and green, and then with a black-and-white
emulsion. With exposure, the silver grains mask some
of the grains of coloured starch to a greater or lesser
degree, and the colours are then restored through an
additive method. Once developed, the image obtained
is a positive visible by transmission.
Calotype (1840–55): Process
patented by William Henry Fox Talbot in 1841 and used
until the mid-1850s. An image is produced by exposure
in a darkroom onto paper sensitized with silver nitrate
and potassium iodide solutions and developing with silver
gallonitrate. The great advantage of this process over
the daguerreotype was the ability to print multiple
positives from a single negative.
Camera obscura: Precursor of the darkroom.
At first, it consisted of a room in which viewers could
see images projected thanks to natural light entering
through a small (pinhole-sized) aperture. Later, this
installation was transformed into a portable box with
an opening, a lens, and a screen. This is the same principle
as that used in a camera.
Chromogenic development print: Process
invented by the Eastman Kodak Company in 1935 to make
colour negatives and slides; it is still in use today.
Positive colour images are composed of organic dyes
in the three primary colours (cyan, magenta, and yellow)
fixed to the paper in layers of binder.
Collage: Image produced by combining
photographs, drawings, and various materials glued onto
Contrast: Relative value of the lightest
and darkest parts of an image.
Copygraphy: Art practice consisting
of diverting photocopiers from their usual purpose to
creative ends. “Copy art” refers to a group
of ways of using photocopiers expressively, whatever
their type (thermographic, chemical, digital, or analog).
Colour photography: In the nineteenth
century, Ducos du Hauron and Gabriel Lippman, taking
completely different paths, produced the first colour
photographs. It was not until the twentieth century
that the first commercial colour processes were invented.
Computer graphics: All computer-generated
graphical representations in point, vectorial, two-dimensional,
or three-dimensional mode.
Contact print: Print obtained by placing
the negative in direct contact with the sensitive surface.
A contact print is the same size as the corresponding
Cyanotype: Invented by Englishman John
Herschel in 1842, the cyanotype made it possible to
produce a positive print directly through the use of
potassium ferricyanide to sensitize the paper. These
permanent, inexpensive prints, also called blueprints,
are still used in architecture today.
Daguerreotype (1839–60): Positive
image obtained on a sheet of silver plated onto copper
in a process invented by Louis-Jacques Mandé
Daguerre and Nicéphore Niepce, and fixed by amalgam.
From 1839 to 1860, it was the most popular form of photograph.
The images obtained with this process showed very fine
detail, but they were also very fragile. As a precaution,
they were displayed under glass, framed, or in a protective
Digital: Said of
any form of electronic recording (image or audio) in
which representation of data or of physical size is
based on binary elements (1 or 0). As opposed to analog.
Environment: In contemporary art,
describes the attitude of artists who want to free themselves
from the limitations of traditional media to extend
the creative act to the surrounding space. These artists
seek to create a relationship between the work of art
and the real world.
Ferrotype: Process invented by Victor
M. Griswold in 1856 and used almost exclusively to produce
inexpensive portraits. The positive image is obtained
by exposing a black-varnished metal plate coated with
a collodion emulsion.
Holography: Method for creating a three-dimensional
image. A laser beam is divided into two parts. One is
reflected by an object and interferes with the other,
which comes directly from the laser. The interference
pattern created when the two beams meet is recorded
on a photographic plate, which, when lit by white light
or laser, gives a three-dimensional image.
Illustrated postcard: Thanks to postal
regulations in the early twentieth century, illustrated
postcards immediately became very popular. These standard
format (8.7 x 13.6 cm) postcards were printed with different
processes, from collotype to half-tone. Postcards remained
one of the richest fields for photography throughout
the twentieth century.
In situ: Latin expression meaning “in
the place.” It is used to designate artworks created
in relation to a specific site.
Installation: In contemporary art,
production that tends to substitute for the notion of
an artwork all of the elements of a work in relation
to the site where it is exhibited or to its environment.
Kirlian: Instrument that makes visible,
through electrical impulses, the energy aura of substances.
It should be noted that this apparatus is not the prerogative
of the occult; it is used mainly for therapeutic purposes.
A careful study of the aura around a body apparently
reveals the presence of disease well before symptoms
Multimedia: This term appeared in the
late 1980s, when CD-ROMs were developed. At the time
it designated applications that, thanks to the storage
capacity of CDs and increased computer memory, could
generate, use, or drive different media simultaneously:
music, audio, images, video, interfaces, human-machine,
interactivity. Today, the word “multimedia”
is used to designate any application using or being
used to operate at least one specific medium.
Negative: Photographic image in which
the values of the subject are inverted; this is the
normal result of development followed by fixing.
Perspective: The concept of perspective
was born during the Renaissance, when natural vision
was for the first time reconstructed by artifices of
representation. Perspective is a geometric method for
representing three-dimensional space in two dimensions.
Photoengraving: Process used since
1852 to produce multiple prints from slides. Today,
photoengraving is still used for high-quality monochrome
Photogenic drawing: William Henry Fox
Talbot was very knowledgeable about silver salts, and
in 1834 he produced the first negatives on paper impregnated
with silver nitrate fixed in a salt solution. These
images were the result of exposure to light of objects
such as leaves and blades of grass placed directly on
Photograph (to): The action of capturing
an image with a camera.
Photomontage: A process of assembling
cut-out photographic elements to obtain a composite
image that is not related to reality.
Positive: Photographic print in which
the light and dark parts correspond to those of the
Print: Image on paper obtained through
Silver gelatin print (1874–....):
Process used since 1880, invented through industrial
research. The negatives are sensitized in the factory
and sold ready to use. At first, glass plates were used,
and then flexible backings (cellulose and, after 1960,
polyester). This process is still used in black-and-white
Stereoscopy: Pair of photographic views
taken beside one another from very slightly different
angles and placed side by side. When they are viewed
separately by each eye through a stereoscopic or binocular
viewer, the two images seem to merge to give the illusion
of three dimensions.
Toning: Chemical processing used to
change the tonality or improve the stability of a photograph.
In the case of silver images, the silver is combined
with another compound, such as gold, platinum, selenium,
Video art: Art form that developed
through the use of electronic media. Its principal tool
is the camcorder, with which moving images and sounds
Glossaire des procédés photographiques.
Ottawa: Musée des beaux-arts du Canada, 1994.
Breuille, J.P., Guillemot, M., and Chiesa, P. Dictionnaire
mondial de la photographie des origines à nos
jours. Paris: Larousse, 2001.
Frizot, Michel, et al. Nouvelle histoire de la photographie.
Paris: Bordas, 1994.
Poissant, Louise, et al. Dictionnaire des arts médiatiques.
Sainte-Foy: Presses de l'Université du Québec,
Rosenblum, Naomi. Une histoire mondiale de la photographie,
New York: Abbeville, 1998.
© 2005 VOX, centre de l’image contemporaine. All rights