HOME WEB NEWS IMAGES CLASSIFIEDS YELLOW PAGESPOLLS - SURVEYS WIKI COUNTRIES PHOTOS US UK INDIA
Cities Stocks Weather Movies Coupons Travel Blogs Health Horoscope Maps ASIA EUROPE Classifieds Yellow Pages
 1
|
|
|
This article or section is in need of attention from an expert on the subject. Please help recruit one or improve this article yourself. See the talk page for details. Please consider using {{Expert-subject}} to associate this request with a WikiProject |
The first permanent color photograph, taken by James Clerk Maxwell in 1861.
An 1877 color photo by Louis Ducos du Hauron, a French pioneer of color photography. The overlapping, yellow, cyan and red subtractive color elements can clearly be seen.
Early color photograph from Russia, created by Sergei Mikhailovich Prokudin-Gorskii as part of his work to document the Russian Empire from 1909 to 1915
An undated color photograph between 1905 and 1915 by Sergei Mikhailovich Prokudin-Gorskii
Color photography is photography that uses media capable of representing colors which are produced chemically during the photographic processing phase. It is contrasted with black-and-white photography, which uses media capable only of showing shades of gray, and does not include hand colored photographs. Some examples of color photography include prints, color negatives, transparencies and slides, and roll and sheet films.
Contents |
The experimentation with creating photographs that mirrored the colors of real life began as early as 1861. It is important to be able to identify different photographic processes because each process may require different methods of preservation.
The first modern ("integrated tri-pack") color film, Kodachrome, was introduced by the Eastman Kodak Company in 1935, using three colored emulsions. Most modern color films, except Kodachrome, are based on technology developed for Agfacolor (as "Agfacolor Neue") in 1936. (In this newer technology, chromogenic dye couplers are already within the emulsion layers, rather than having to be carefully diffused in during development.) Instant color film was introduced by Polaroid in 1963.
Several commercial print methods were devised using the subtractive technique during the 1930s (see e.g. Coe, ref 1), for printing from "separation negatives". Kodachrome was the first commercially-available film of this type.
Numerous factors can deteriorate and even destroy photographs. Some examples include:
However, an important property of color photographic materials to understand is that they are not permanent and by nature are instable. Chromogenic color photographs, for example, are composed of yellow, magenta, and cyan organic dyes which fade at different rates. Even when in dark storage and enclosed in the proper archival materials, deterioration is unavoidable, but fading, color shifting, and discoloration can be delayed when given the proper preservation care.
Three signs of age that affect color photography are:
Dark fading occurs regardless of the procedures taken to preserve a photograph and is unavoidable. It is instigated by temperature and RH. Cyan dyes will typically fade more quickly, which will make the image appear too red in color.
Light fading occurs when materials are exposed to light, e.g. while on display. The intensity of the light source and ultraviolet (UV) rays will effect the rate of change and fade. Magenta dyes will typically fade the quickest.
Highlight staining occurs with older color photographic papers, and is a yellowing of the border and highlight areas of a photograph.
In general, the colder the storage, the longer the "life" of color photographs. Frost-free refrigeration, more commonly known as cold storage (below freezing) is one of the most effective ways to bring a halt to developing damage to color photographic materials. However, selecting this type of storage environment is costly and requires special training to remove items and return items. Therefore, cool storage (above freezing) is more common and less costly, which requires that the temperature is consistently between 10°C – 15°C (50°F – 60°F) with 30–40% relative humidity with special attention to dew point to eliminate concerns for condensation. General dark storage in light tight enclosures and storage boxes is always advised for individual items. When materials are exposed to light during handling, usage, or display - light sources should be UV-filtered and intensity kept at minimum. In storage areas, 200–400 lux is recommended.
The usage of enclosures is the easiest method of preserving photographic materials from being damaged through handling and light exposure. All protective materials should pass the Photographic Activity Test (PAT) as described both by the American National Standards Institute (ANSI) in standard IT9.2-1988, and the International Organization for Standardization (ISO) in standard 18916:2007(E), Photography – Processed Photographic Materials – Photographic Activity Test for Enclosure Materials. The PAT is an archival science test that determines what kind of enclosures will preserve, prevent, and/or prolong from further deterioration while in storage.
The recommended use of archival enclosures includes each item having its own enclosure and that each enclosure is of the appropriate size. Archival enclosures may come in two different forms: paper or plastic. Choosing either option has its advantages and disadvantages.
After photographic materials are individually enclosed, housing or storage containers provide another protective barrier such as folders and boxes made from archival paperboard as addressed in ISO Standards 14523 and 10214. Sometimes these containers have to be custom-made in order to properly store odd sizes. In general, flat storage of in boxes is recommended because it provides more stable support, particularly for materials that are in more fragile condition. Still, boxes and folders should never be over-filled with materials.
| This short section requires expansion. |
This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia
