Kodachrome is the brand name for a color reversal film introduced by Eastman Kodak in 1935.

For many years, Kodachrome was widely used for professional color photography, especially for images intended for publication in print media.

Eventually, the growth and popularity of alternative photographic materials, and, much later, the widespread transition to digital photography, led to Kodachrome’s loss of market share.

In early 2017, Kodak announced it was investigating the possibility of re-introducing Kodachrome,[4] but later conceded that this was unlikely to happen.

It was manufactured for 74 years in various formats to suit still and motion picture cameras, including 8mm, Super 8, 16mm for movies (exclusively through Eastman Kodak), 35mm for movies (exclusively available through Technicolor Corp as "Technicolor Monopack") and 135, 120, 110, 126, 828 and large format for still photography.

Kodachrome is appreciated in the archival and professional market for its accurate color reproduction and dark-storage longevity.

It was used by McCurry for his iconic 1984 portrait of Sharbat Gula, Afghan Girl, for the National Geographic magazine.

The color rendition of this additive two-color process was of fair quality, but aligning the two lenses of the projector was difficult.

Mees offered to help, and after meeting with Mannes and Godowsky, agreed to supply them with multi-layer emulsions made to their specifications.

The pair then secured a $20,000 loan from the New York investment firm Kuhn, Loeb and Company, instigated by a secretary there that Mees had befriended.

He knew that the solution to the problem of the wandering dyes had already been found by one of Kodak's scientists, Leslie Brooker, and so fronted Mannes and Godowsky the money to pay off their loan with Kuhn Loeb and offered them a yearly salary, coupled to a three-year deadline to come up with a finished and commercially viable product.

Shortly before their deadline at the end of 1933, Mannes and Godowsky had not produced anything usable, and thought their experiments would be terminated by Kodak.

Mees immediately set things in motion to produce and market this film, but just before Kodak was about to do so in 1935, Mannes and Godowsky completed work on the long-awaited but no longer expected, much better, three-color version.

[22] In 1961, Kodak released Kodachrome II with sharper images and faster speeds at 25 ASA.

On June 22, 2009, Kodak announced it would no longer manufacture Kodachrome film, citing declining demand.

[7] During its heyday, many Kodak and independent laboratories processed Kodachrome, but by 2010, only one Kodak-certified facility remained: Dwayne's Photo in Parsons, Kansas.

After announcing the return of Ektachrome at the beginning of 2017, Eastman Kodak CMO Steven Overman told The Kodakery podcast, "we are investigating Kodachrome, looking at what it would take to bring that back".

[4] Although the statement generated widespread media interest, it was subsequently conceded by an official at Kodak Alaris (which would be responsible for its production and sale) that the return of Kodachrome was probably impractical (due to the difficulty in restoring the now-dismantled infrastructure needed to support it) and therefore unlikely.

For professional uses, where duplication is expected and required, a special version, Kodachrome Commercial (KCO), was available in a 35 mm BH-perforated base (exclusively through Technicolor) and in a 16 mm base (exclusively through Eastman Kodak's professional products division).

Kodachrome Commercial has a low-contrast characteristic that complements the various duplication films with which it is intended to be used: silver separation negatives for 35 mm (controlled exclusively by Technicolor) and reversal duplicating and printing stocks for 16 mm (controlled exclusively by Eastman Kodak).

When stored in darkness, Kodachrome's long-term stability under suitable conditions is superior to other types of color film of the same era.

Nevertheless, Kodachrome's color stability under bright light, for example during projection, is inferior to substantive slide films.

These effects can sometimes cause a slight loss of sharpness in the scanned image when Digital ICE or a similar infrared channel dust removal function is used.

The red-sensitive layer was re-exposed through the base of the film with red light, then redeveloped forming cyan dye.

The blue-sensitive layer was re-exposed through the emulsion side of the film with blue light, then redeveloped forming yellow dye.

The film was then fixed, making these silver halides soluble and leaving only the final dye image.

The Parliamentary committees for Culture and Education[56] and for Internal Market and Consumer Protection[57] studied the matter.

[60][64] The cessation of processing by Dwayne's Photo is commemorated in the book Kodachrome – End of the Run: Photographs from the Final Batches, edited by photographers Bill Barrett and Susan Hacker Stang with introductory essays by Time magazine worldwide pictures editor Arnold Drapkin and Dwayne's Photo vice president Grant Steinle.

The book presents a year of pictures shot by Webster University photography students on more than 100 rolls of by-then rare Kodachrome film and processed by Dwayne's on the last day (extended to January 18, 2011) before processing chemicals officially ceased production.

[71] Anticipating the approval of their merger, in 1985, the Southern Pacific and Santa Fe railroad companies repainted hundreds of locomotives into a unified red and yellow livery, which railfans nicknamed "Kodachrome".