Darkroom
Encyclopedia
A darkroom is a room that can be made completely dark to allow the processing of light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

 sensitive photographic materials, including photographic film
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...

 and photographic paper
Photographic paper
Photographic paper is paper coated with light-sensitive chemicals, used for making photographic prints.Photographic paper is exposed to light in a controlled manner, either by placing a negative in contact with the paper directly to produce a contact print, by using an enlarger in order to create a...

. Darkrooms have been created and used since the inception of photography in the early 19th century. Darkrooms have many various manifestations, from the elaborate space used by Ansel Adams
Ansel Adams
Ansel Easton Adams was an American photographer and environmentalist, best known for his black-and-white photographs of the American West, especially in Yosemite National Park....

 to a retooled ambulance wagon used by Timothy H. O'Sullivan
Timothy H. O'Sullivan
Timothy H. O'Sullivan was a photographer widely known for his work related to the American Civil War and the Western United States.O'Sullivan was born in New York City. As a teenager, he was employed by Mathew Brady...

. From the initial development to the creation of prints, the darkroom process allows complete control over the medium.

Due to the popularity of color photography and complexity of processing colour film (see C-41 process
C-41 process
C-41 is a chromogenic color print film developing process. C-41, also known as CN-16 by Fuji, CNK-4 by Konica, and AP-70 by AGFA, is the most popular film process in use, with most photofinishing labs devoting at least one machine to this development process....

) and printing color photographs and also to the rise, first of Polaroid
Polaroid Corporation
Polaroid Corporation is an American-based international consumer electronics and eyewear company, originally founded in 1937 by Edwin H. Land. It is most famous for its instant film cameras, which reached the market in 1948, and continued to be the company's flagship product line until the February...

 technology and later digital photography
Digital photography
Digital photography is a form of photography that uses an array of light sensitive sensors to capture the image focused by the lens, as opposed to an exposure on light sensitive film...

, darkrooms are decreasing in popularity, though are still commonplace on college campuses, schools and in the studios of many professional photographers.

Darkroom equipment

In most darkrooms, an enlarger
Enlarger
An enlarger is a specialized transparency projector used to produce photographic prints from film or glass negatives using the gelatin silver process, or from transparencies.-Construction:...

, an optical apparatus similar to a slide projector, that projects the image of a negative
Negative (photography)
In photography, a negative may refer to three different things, although they are all related.-A negative:Film for 35 mm cameras comes in long narrow strips of chemical-coated plastic or cellulose acetate. As each image is captured by the camera onto the film strip, the film strip advances so that...

 onto a base, finely controls the focus, intensity and duration of light, is used for printmaking. A sheet of photographic paper
Photographic paper
Photographic paper is paper coated with light-sensitive chemicals, used for making photographic prints.Photographic paper is exposed to light in a controlled manner, either by placing a negative in contact with the paper directly to produce a contact print, by using an enlarger in order to create a...

 is exposed to the enlarged image from the negative.

When making black-and-white prints, a safelight
Safelight
A safelight is a light source suitable for use in a photographic darkroom. It provides illumination only from parts of the visible spectrum to which the photographic material in use is nearly or completely insensitive.- Design :...

 is commonly used to illuminate the work area. Since the majority of black-and-white papers are sensitive to only blue, or to blue and green light, a red- or amber-coloured light can be safely used without exposing the paper.

Color print paper, being sensitive to all parts of the visible spectrum, must be kept in complete darkness until the prints are properly fixed.

Another use for a darkroom is to load film in and out of cameras, development spools, or film holders, which requires complete darkness. Lacking a darkroom, a photographer can make use of a changing bag
Changing bag
A changing bag is a photographic bag specifically designed to be light-proof while in use. It is required for certain applications involving photosensitive materials when a darkroom is not available, like in the field. Common usages include removing film from its canister to put it into a...

, which is a small bag with sleeved arm holes specially designed to be completely light proof and used to prepare film prior to exposure or developing.

Print processing

During exposure, values in the image can be adjusted, most often by "dodging" (reducing the amount of light to a specific area of an image by selectively blocking light to it for part or all of the exposure time) and/or "burning" (giving additional exposure to specific area of an image by exposing only it while blocking light to the rest). Filters, usually thin pieces of colored plastic, can be used to increase or decrease an image's contrast (the difference between dark tones and light tones). After exposure, the photographic printing paper (which still appears blank) is ready to be processed.

Photographers generally begin printing a roll of film by making a contact print
Contact print
A contact print is a photographic image produced from film; sometimes from a film negative, and sometimes from a film positive. The defining characteristic of a contact print is that the photographic result is made by exposing through the film negative or positive, onto a light sensitive material...

 of their negatives to use as a quick reference to decide which images to enlarge. Some large format
Large format
Large format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage...

 photographers, such as Edward Weston
Edward Weston
Edward Henry Weston was a 20th century American photographer. He has been called "one of the most innovative and influential American photographers…" and "one of the masters of 20th century photography." Over the course of his forty-year career Weston photographed an increasingly expansive set of...

, make only contact prints of their large (4x5", 5x7", 8x10" or larger) negatives.

The paper that has been exposed is processed, first by immersion in a photographic developer
Photographic developer
In the processing of photographic films, plates or papers, the photographic developer is a chemical that makes the latent image on the film or print visible. It does this by reducing the silver halides that have been exposed to light to elemental silver in the gelatine matrix...

, halting development with a stop bath
Stop bath
Stop bath is a chemical bath usually used in processing traditional black-and-white photographic films, plates, and paper used after the material has finished developing. The purpose of the stop bath is to halt the development of the film, plate, or paper by either washing off the developing...

, and fixing in a photographic fixer
Photographic fixer
Photographic fixer is a chemical or a mix of chemicals used in the final step in the photographic processing of film or paper. The fixer stabilises the image, removing the unexposed silver halide remaining on the photographic film or photographic paper, leaving behind the reduced metallic silver...

. The print is then washed
Washing (photography)
In photography, washing is an important part of all film processing and printmaking processes. After materials have been fixed, washing removes unwanted and exhausted processing chemicals which, if left in situ, may cause deterioration and destruction of the image.A disadvantage of the use of...

 to remove the processing chemicals and dried. There are a variety of other, additional steps a photographer may take, such as toning.

See also

  • Photographic plate
    Photographic plate
    Photographic plates preceded photographic film as a means of photography. A light-sensitive emulsion of silver salts was applied to a glass plate. This form of photographic material largely faded from the consumer market in the early years of the 20th century, as more convenient and less fragile...

  • Stop bath
    Stop bath
    Stop bath is a chemical bath usually used in processing traditional black-and-white photographic films, plates, and paper used after the material has finished developing. The purpose of the stop bath is to halt the development of the film, plate, or paper by either washing off the developing...

  • List of photographic processes
  • Photographic studio
    Photographic studio
    A photographic studio is both a workspace and a corporate body. As a workspace it is much like an artist’s studio, but providing space to take, develop, print and duplicate photographs. Photographic training and the display of finished photographs may also be accommodated in a photographic studio...

  • Digital darkroom
    Digital darkroom
    Digital "darkroom" is the hardware, software and techniques used in digital photography that replace the darkroom equivalents, such as enlarging, cropping, dodging and burning, as well as processes that don't have a film equivalent....


External links

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