Editing Photography (section)

=== Film ===
{{Main|Photographic film}}
[[File:undeveloped film.png|thumb|upright=1.6|right|Undeveloped Arista black-and-white film, [[Film speed|ISO]] 125/22°]]

[[Hurter and Driffield]] began pioneering work on the [[sensitometry|light sensitivity]] of photographic emulsions in 1876. Their work enabled the first quantitative measure of film speed to be devised.

The first flexible photographic roll film was marketed by [[George Eastman]], founder of [[Kodak]] in 1885, but this original "film" was actually a coating on a paper base. As part of the processing, the image-bearing layer was stripped from the paper and transferred to a hardened gelatin support. The first transparent plastic roll film followed in 1889.<!--am leaving this date untouched, but it is a matter of some controversy--> It was made from highly flammable [[nitrocellulose#Film|nitrocellulose]] known as nitrate film.

Although [[cellulose acetate]] or "[[safety film]]" had been introduced by Kodak in 1908,<ref>[http://www.kodak.com/global/en/corp/historyOfKodak/1878.jhtml History of Kodak, Milestones-chronology: 1878–1929] {{Webarchive|url=https://web.archive.org/web/20120210123011/http://www.kodak.com/global/en/corp/historyOfKodak/1878.jhtml |date=10 February 2012}}. kodak.com</ref> at first it found only a few special applications as an alternative to the hazardous nitrate film, which had the advantages of being considerably tougher, slightly more transparent, and cheaper. The changeover was not completed for [[X-ray]] films until 1933, and although safety film was always used for 16&nbsp;mm and 8&nbsp;mm home movies, nitrate film remained standard for theatrical 35&nbsp;mm motion pictures until it was finally discontinued in 1951.

Films remained the dominant form of photography until the early 21st century when advances in digital photography drew consumers to digital formats.<ref>{{cite book
| last      = Peres
| first     = Michael R.
| title     = The Concise Focal Encyclopedia of Photography: from the first photo on paper to the digital revolution
| date      = 2008
| publisher = Focal Press/Elsevier
| location  = Burlington, MA
| isbn      = 978-0-240-80998-4
| page      = 75
}}</ref> Although modern photography is dominated by digital users, film continues to be used by enthusiasts and professional photographers. The distinctive "look" of film based photographs compared to digital images is likely due to a combination of factors, including (1) differences in spectral and tonal sensitivity (S-shaped density-to-exposure (H&D curve) with film vs. linear response curve for digital CCD sensors),<ref>{{cite web
| url          = http://www.dpreview.com/forums/post/8473695
| title        = H&D curve of film vs digital
| date         = 19 April 2004
| website      = Digital Photography Review
| format       = Forum Discussion
| archive-url  = https://web.archive.org/web/20150923223829/http://www.dpreview.com/forums/post/8473695
| archive-date = 23 September 2015
| url-status   = live
}}</ref> (2) resolution, and (3) continuity of tone.<ref>{{cite book
| last1      = Jacobson
| first1     = Ralph E.
| title      = The Focal Manual of Photography: photographic and digital imaging
| date       = 2000
| publisher  = Focal Press
| location   = Boston, MA
| isbn       = 978-0-240-51574-8
| edition    = 9th
| url-access = registration
| url        = https://archive.org/details/digitalvideocame00pete
}}</ref>