A photograph (often shortened to photo) is an
imagecreated by lightfalling on a light-sensitive surface, usually photographic filmor an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of what the human eye would see. The process of creating photographs is called photography. The word "photograph" coined 1839 by Sir John Herscheland is based on the Greek "φώς" ("phos"), "light" + "γραφίς" ("graphis"), "stylus", "paintbrush" or "γραφή" ("graphê"), "representation by means of lines" or "drawing", together meaning "drawing with light". [ [http://www.etymonline.com/index.php?search=photography&searchmode=none Online Etymology Dictionary] ]
The first permanent photograph was made in
1826by a French inventor, Joseph Nicéphore Niépce, building on a discovery by Johann Heinrich Schultz(1724): that a silver and chalk mixture darkens under exposure to light. Niépce and Louis Daguerrerefined this process. Daguerre discovered that exposing the silver first to iodine vapor, before exposure to light, and then to mercury fumes after the photograph was taken, could form a latent image; bathing the plate in a salt bath then fixes the image. These ideas led to the famous daguerreotype.
The daguerreotype had its problems, notably the fragility of the resulting picture, and that it was a positive-only process and thus could not be re-printed. Inventors set about looking for improved processes that would be more practical. Several processes were introduced and used for a short time between Niépce's first image and the introduction of the
collodion processin 1848. Collodion-based wet-glass plate negatives with prints made on albumen paper remained the preferred photographic method for some time, even after the introduction of the even more practical gelatin processin 1871. Adaptations of the gelatin process have remained the primary black-and-whitephotographic process to this day, differing primarily in the film material itself, originally glass and then a variety of flexible films.
Color photography is almost as old as black-and-white, with early experiments dating to
John Herschel's experiments with Anthotypefrom 1842, and Lippmann platefrom 1891. Color photography became much more popular with the introduction of Autochrome Lumièrein 1903, which was replaced by Kodachrome, Ilfochromeand similar processes. For many years these processes were used almost exclusively for transparencies (in slide projectors and similar devices), but color prints became popular with the introduction of the Chromogenicnegative, which is the most-used system in the C-41 process. The needs of the movie industry have also introduced a host of special-purpose systems, perhaps the most well known being the now-rare Technicolor.
Types of photographs
Non-digital photographs are produced with a two-step chemical process. In the two-step process the light-sensitive film captures a "negative" image (colors and lights/darks are inverted). To produce a "positive" image, the negative is most commonly transferred ('printed') onto
photographic paper. Printing the negative onto transparent film stock is used to manufacture motion picture films.
Alternatively, the film is processed to invert the "negative" image, yielding positive transparencies. Such positive images are usually mounted in frames, called slides. Before recent advances in digital photography, transparencies were widely used by professionals due to their sharpness and accuracy of color rendition. Most photographs published in magazines were taken on color transparency film.
Originally all photographs were monochromatic, or hand-painted in color. Although methods for developing color photos were available as early as 1861, they did not become widely available until the 1940s or 50s, and even so, until the 1960s most photographs were taken in black and white. Since then,
Color photographyhas dominated popular photography, although black and white is still used, being easier to develop than color. Panoramic formatimages can be taken with cameras like the HasselbladXpan on standard film. Since the 1990s, panoramic photos have been available on the Advanced Photo Systemfilm. APS was developed by several of the major film manufacturers to provide a film with different formats and computerized options available, though APS panoramas were created using a mask in panorama-capable cameras, far less desirable than a true panoramic camera which achieves its effect through wider film format. APS has become less popular and is being discontinued.
The advent of the
microcomputerand digital photography has led to the rise of digital prints. These prints are created from stored graphic formats such as JPEG, TIFF, and RAW. The types of printers used include inkjet printers, dye-sublimation printer, laser printers, and thermal printers. Inkjet prints are sometimes given the coined name " Giclée".
Ideal photograph storage involves placing each photo in an individual folder constructed from buffered, or
acid-free paper. [Albright, Gary. “Storage Enclosures for Photographic Materials.” Northeast Document Conservation Center. 2007. 9 Feb. 2008.http://www.nedcc.org/resources/leaflets/4Storage_and_Handling/11StorageEnclosures.php. ] Buffered paper folders are especially recommended in cases when a photograph was previously mounted onto poor quality material or using an adhesivethat will lead to even more acidcreation. [Norris, Debbie Hess. “Caring for Your Photographic Collections.”Library of Congress. Feb. 9 2008. www.loc.gov/preserv/care/photo.html] Store photographs measuring 8x10 inches or smaller vertically along the longer edge of the photo in the buffered paper folder, within a larger archival box, and label each folder with relevant information in order to identify it. The rigid nature of the folder protects the photo from slumping or creasing, as long as the box is not packed too tightly or under filled. Folder larger photos or brittle photos stacked flat within archival boxes with other materials of comparable size. [ “How Should I Store my Photographic Prints?” Preservation and Archives Professionals. The National Archives and Records Administration. 9 Feb. 2008.www.archives.gov/preservation/family-archives/storing-photos.html]
The most stable of plastics used in photo preservation,
polyester, does not generate any harmful chemical elements, but nor does it have any capability to absorb acidsgenerated by the photograph itself. Polyester sleeves and encapsulation have been praised for their ability to protect the photograph from humidityand environmental pollution, slowing the reaction between the item and the atmosphere. This is true, however the polyester just as frequently traps these elements next to the material it is intended to protect. This is especially risky in a storage environment that experiences drastic fluctuations in humidity or temperature, leading to ferrotyping, or sticking of the photograph to the plastic. [Albright, Gary. “Storage Enclosures for Photographic Materials.” Northeast Document Conservation Center. 2007. 9 Feb. 2008.http://www.nedcc.org/resources/leaflets/4Storage_and_Handling/11StorageEnclosures.php. ] Photographs sleeved or encapsulated in polyester cannot be stored vertically in boxes because they will slide down next to each other within the box, bending and folding, nor can the archivistwrite directly onto the polyester to identify the photograph. Therefore, it is necessary to either stack polyester protected photographs horizontally within a box, or bind them in a three ring binder. Stacking the photos horizontally within a flat box will greatly reduce ease of access, and binders leave three sides of the photo exposed to the effects of light [International Organization for Standardization. ISO 18902:2001(E). Geneva,Switzerland: ISO Office, 2007.] and do not support the photograph evenly on both sides, leading to slumping and bending within the binder. The plastic used for enclosures has been manufactured to be as frictionless as possible in order to prevent abrading and scratching the photos during insertion to the sleeves. Unfortunately, the slippery nature of the enclosure generates a build-up of static electricity, which attracts dustand lint particles. The static can attract the dust to the inside of the sleeve, as well, where it can scratch the photograph. [Albright, Gary. “Storage Enclosures for Photographic Materials.” Northeast Document Conservation Center. 2007. 9 Feb. 2008.http://www.nedcc.org/resources/leaflets/4Storage_and_Handling/11StorageEnclosures.php. ] Likewise, these components that aid in insertion of the photo, referred to as slip agents, can break down and transfer from the plastic to the photograph, where they deposit as an oily film, attracting further lint and dust. At this time, there is no test to evaluate the long-term effects of these components on photographs. In addition, the plastic sleeves can develop kinks or creases in the surface, which will scratch away at the emulsionduring handling. [International Organization for Standardization. ISO 18902:2001(E). Geneva,Switzerland: ISO Office, 2007.]
Handling and care
It is best to leave photographs lying flat on the table when viewing them. Do not pick it up from a corner, or even from two sides and hold it at eye level. Every time the photograph bends, even a little, this can break down the
emulsion. [Baggett, James L. “Handle with Care: Photos.” Alabama Librarian. 54.1 (2004): 5.] The very nature of enclosing a photograph in plastic encourages users to pick it up; users tend to handle plastic enclosed photographs less gently than non-enclosed photographs, simply because they feel the plastic enclosure makes the photo impervious to all mishandling. As long as a photo is in its folder, there is no need to touch it; simply remove the folder from the box, lay it flat on the table, and open the folder. If for some reason the researcher or archivistdoes need to handle the actual photo, perhaps to examine the verso for writing, he or she can use gloves if there appears to be a risk from oils or dirt on the hands.
Myths and beliefs
Photographs capture a life-like view of the subject whereas paintings were subject to the interpretations and level of skill of the painter. Thus, since daguerreotypes were rendered on a mirrored surface, many spiritualists also became practitioners of the new art form. Spiritualists would claim that the human image on the mirrored surface was akin to looking into one's soul. The spiritualists also believed that it would open their souls and let demons in. Aborigines believed that taking one's picture took part of one's soul away.
Largest photographs in the world
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