Kodachrome

Before Kodachrome film was marketed in 1935 most color photography had been achieved using films that employed additive color methods and materials, such as Autochrome and Dufaycolor,[9] These first practical color processes had several disadvantages because they used a réseau filter made from discrete color elements that were visible upon enlargement. The finished transparencies absorbed between 70% and 80% of light upon projection, requiring very bright projection lamps, especially for large projections. Subtractive color methods avoided these disadvantages.[10]

Rudolf Fischer was granted a patent in 1913 for a proposed color photography process in which three separate emulsions, each sensitive to a different color, would be exposed simultaneously.[11] However, Fischer was unable to implement the idea.[12]^: 215

The first Kodak product called Kodachrome was invented by John Capstaff in 1913.[13] His Kodachrome was a subtractive process that used only two colours: blue-green and red-orange. It required two glass plate negatives, one made using a panchromatic emulsion and a red filter, the other made using an emulsion insensitive to red light. The two plates could be exposed as a "bipack" (sandwiched emulsion to emulsion, with a very thin red filter layer between), which eliminated the need for multiple exposures or a special color camera. After development, the silver images were bleached out with chemistry that hardened the bleached portions of the gelatin. Using dyes that were absorbed only by the unhardened gelatin, the negative that recorded the blue and green light was dyed red-orange and the red-exposed negative was dyed blue-green. The result was a pair of positive dye images. The plates were then assembled emulsion to emulsion, producing transparency that was capable of surprisingly good (for a two-colour process) colour rendition of skin tones in portraits. Capstaff's Kodachrome was made commercially available in 1915. It was also adapted for use as a 35 mm motion picture film process.[14] Today, this first version of Kodachrome is nearly forgotten, completely overshadowed by the next Kodak product bearing the same name Kodacrome.

In 2012 Capstaff's early film tests were added to the United States Library of Congress National Film Registry under the title Two-Color Kodachrome Test Shots No. III (1922) for being “culturally, historically or aesthetically” significant."[15][16]

The next version of Kodachrome was invented in the early 1930s by two professional musicians, Leopold Godowsky Jr. and Leopold Mannes,[17] who were also university-trained scientists.[18][19]

Mannes and Godowsky first took an interest in color photography in as high school pupils in 1917, when they saw a movie called Our Navy,[20] a movie production using a four-color additive process. Both agreed the color was terrible. After reading up on the subject in the library they started to experiment with additive color processes. Their experiments were continued during their college years, eventually producing a camera having two lenses that projected images side by side on a single strip of film. The color rendition of this additive two-color process was not too bad, but aligning the two lenses of the projector was difficult.

Their experiments, which continued after they finished college, turned from multiple lenses that produced multiple, differently colored images that had to be combined to form the final transparency, to multiple layered film in which the different color images were already combined, perfectly aligned. Such a multi-layered film had already been invented and patented in 1912 by the German inventor Rudolph Fischer. Each of the three layers in the proposed film would be sensitive to one of the three primary colors, and each of the three layers would have substances (called "color couplers") embedded in them that would form a dye of the required color when combined with the by-products of the developing silver image. When the silver images were bleached away, the three-color dye image would remain. Fischer, however, failed to find a way to stop the color couplers and color sensitizing dyes from wandering from one layer into the other, where they would produce unwanted colors.

Mannes and Godowsky followed that route, and started experimenting with color couplers, but their experiments were hindered by a lack of money, supplies and facilities. In 1922 Robert Wood, a friend of Mannes, wrote a letter of introduction for Mannes and Godowsky to Kodak chief scientist Kenneth Mees, referencing their experiments and asking if Mees could let them use the Kodak facilities for a few days. 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 Mees had befriended.

By 1924 they were able to patent a two-color process that employed "controlled diffusion". By timing how long it took for an image to form in the top layer ahead of the lower they began to probe the prospects of timed processing as a means of controlling wandering dyes. Some three years later they were still experimenting with such a method in a multi-layer emulsion, but by then they had decided that instead of incorporating the color couplers into the emulsion layers themselves, they could be added to the developing chemicals.

When their money ran out in 1929 Mees decided to help them once more. He knew that the solution to the problem of the wandering dyes had already been found by one of Kodak's own scientists, Leslie Brooker. So he 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.

Not long before time was to expire at the end of 1933 Mannes and Godowsky still had not managed to come up with anything usable, and thought their experiments would be terminated by Kodak. Instead, Mees granted them a one-year extension and, still having technical challenges they needed to solve, they eventually presented Mees with a mere two-color movie process in 1934, just as the original Kodachrome invented by John Capstaff some 20 years earlier had been.

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. On April 15, 1935, this new film, borrowing the name from Capstaff's process, was formally announced.[14]

Ciné-Kodak Kodachrome 8mm movie film (expired: May 1946)

Kodachrome was first sold in 1935 as 16 mm movie film with an ASA speed of 10[21][22] and the following year it was made available as 8 mm movie film, and in 35mm and 828 formats for still cameras.[23]

In 1961 Kodak released Kodachrome II with sharper images and faster speeds at 25 ASA.[24] In 1962, Kodachrome-X at ASA 64 was introduced. In 1974, with the transition to the K-14 process Kodachrome II and Kodachrome-X were replaced by Kodachrome 25 and Kodachrome 64.[25]

In later years, Kodachrome was produced in a wide variety of film formats including 120 and 4 in × 5 in (100 mm × 130 mm), and in ISO-ASA values ranging from 8 to 200.[26]

Until manufacturing was taken over by rival film manufacturer GAF, View-Master stereo reels used Kodachrome films.

Later color transparency films, such as Agfachrome, Anscochrome, Fujichrome and Kodak's own Ektachrome used simpler, quicker, and more accessible color development processes. Their higher film speeds also eroded Kodachrome's market share, as the quality of competing films improved over time. As digital photography reduced the demand for all film after 2000, Kodachrome sales further declined. 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.[27] On July 14, 2010, it was announced[28] that the last roll of Kodachrome manufactured had been developed by Dwayne's for photographer Steve McCurry, a National Geographic photographer. McCurry had asked Kodak for the last roll in stock, then went out on his own to use that roll.[29] Although McCurry retains ownership of the slides, prints of the 36 exposures are permanently housed at the George Eastman House in Rochester, New York[28] and most of the pictures have been published on the Internet by Vanity Fair magazine.

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.[5]

Kodachrome films are non-substantive. Unlike substantive transparency and negative color films, Kodachrome film does not incorporate dye couplers into the emulsion layers. The dye couplers are added during processing.[30] This means that Kodachrome emulsion layers are thinner and less light is scattered upon exposure, meaning that the film could record an image with more sharpness than substantive films.[31] Transparencies made with non-substantive films have an easily visible relief image on the emulsion side of the film.[32] Kodachrome 64 and 200 can record a dynamic range of about 2.3D or 8 stops, as shown in the characteristic curves.[33] Kodachrome 25 transparencies have a dynamic range of around 12 stops, or 3.6–3.8D.[34]

The color rendering of Kodachrome films was unique in color photography for several decades after its introduction in the 1930s.[35] Even after the introduction of other successful professional color films, such as Fuji Velvia, some professionals continued to prefer Kodachrome, and maintain that it still has certain advantages over digital. Steve McCurry told Vanity Fair magazine:[36]

If you have good light and you're at a fairly high shutter speed, it's going to be a brilliant color photograph. It had a great color palette. It wasn't too garish. Some films are like you're on a drug or something. Velvia made everything so saturated and wildly over-the-top, too electric. Kodachrome had more poetry in it, a softness, an elegance. With digital photography, you gain many benefits [but] you have to put in post-production. [With Kodachrome,] you take it out of the box and the pictures are already brilliant.[36]

Kodachrome is generally used for direct projection using white light. As such, it possesses a relatively high contrast.

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). In both cases, Eastman Kodak performed the processing.

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).

Kodachrome Commercial was available until the mid-1950s, after which Ektachrome Commercial (ECO) replaced it for these specific applications.

After the late 1950s, 16 mm Kodachrome Commercial-originated films (and Ektachrome Commercial-originated films as well) were quite often duplicated onto Eastmancolor internegative film, after which these films were printed on Eastmancolor positive print film, as a cost-reduction measure, thereby yielding relatively low-cost prints for direct projection.

When stored in darkness, Kodachrome's long-term stability under suitable conditions is superior to other types of color film of the same era. While existing Kodachrome materials from before Kodak simplified the development process in 1938[37] are almost always faded, images on Kodachrome slides and motion picture films made after this point retain accurate color and density to this day. It has been calculated that the yellow dye, the least stable, would suffer a 20% loss of dye in 185 years.[38] This is because developed Kodachrome does not retain unused color couplers. Nevertheless, Kodachrome's color stability under bright light, for example during projection, is inferior to substantive slide films. Kodachrome's fade time under projection is about one hour, compared to Fujichrome's two and a half hours.[39]

Unprocessed Kodachrome film may survive long periods between exposure and processing. In one case, several rolls were exposed and then lost in a Canadian forest. Upon discovery 19 years later they were processed and the slides were usable.[40]

A 35mm Kodachrome transparency, like other 35mm transparencies on films of comparable ISO rating, contains an equivalent of approximately 20 megapixels of data in the 24 mm x 36 mm image.[41] Scanning Kodachrome transparencies can be problematic because of the film's tendency to scan with a blue color cast.[34] Some software producers deliver special Kodachrome color profiles with their software to avoid this. An IT8 calibration with a special Kodachrome calibration target is necessary for accurate color reproduction.[42]

Many scanners use an additional infrared channel to detect defects, as the long wave infrared radiation passes through the film but not through dust particles. Dust, scratches, and fingerprints on the slide are typically detected and removed by a scanner's software. Kodachrome interacts with this infrared channel in two ways. The absorption of the cyan dye extends into the near infrared region, making this layer opaque to infrared radiation.[43] Kodachrome also has a pronounced relief image that can affect the infrared channel. 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.[44]

Due to its complex processing requirements, Kodachrome film was initially sold at a price that included processing by Kodak.[48] An envelope was included with the film in which the photographer would send the exposed film to the nearest of several designated Kodak laboratories.[49] The film was processed, mounted in 2 in × 2 in (51 mm × 51 mm) cardboard mounts in the case of 35 mm slides, and returned by mail to the sender. After 1954, as a result of a lawsuit from the federal government, this practice was prohibited in the United States as anticompetitive. Kodak entered into a consent decree that ended this practice in the United States, and allowed independent processing laboratories to acquire the chemicals needed to process Kodachrome films.[50][51] In other countries, the price of Kodachrome film continued to include processing by Kodak.

After its Lausanne processing facility closed, Kodak subcontracted the processing work to Dwayne's Photo, an independent facility in the United States, which became the world's last Kodachrome processing facility.[59] Dwayne's processing of 35 mm films was fully endorsed by Kodak, but its Super-8 process was not endorsed because it required more agitation.[59] Films sent for processing in the USA were mailed directly to Dwayne's, while those in Europe were sent to the Lausanne facility's address and forwarded to Dwayne's.[60]

Dwayne's Photo announced in late 2010 that it would process all Kodachrome rolls received at the lab by December 30, 2010, after which processing would cease.[61][62][63] As Dwayne's final processing deadline approached, thousands of stored rolls of film were sent in for processing.[63][64] Once film received by the deadline had been developed, the world's last K-14 processing machine was taken out of service.[65] The final roll to be processed was exposed by Dwayne Steinle, owner of Dwayne's Photo.[65][66] 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.[67] Kodachrome film can no longer be processed in color, but it can be processed in black and white by some labs that specialize in obsolete processes and old film processing.

Kodachrome 200 – Film for colour slides

The Kodachrome product range diminished progressively through the 1990s and 2000s.

• Kodachrome 64 film in 120 format was discontinued in 1996.[26]
• Kodachrome 25 was discontinued in 2002.
• Kodachrome 40 in the Super 8 movie format was discontinued in June 2005,[68] despite protests from filmmakers.[69] Kodak launched a replacement color reversal film in the Super 8 format, Ektachrome 64T, which uses the common E-6 processing chemistry.[70]
• Kodachrome 200 was discontinued in November 2006.
• Kodachrome 64 and Kodachrome 64 Professional 135 format were discontinued in June 2009.[71][72]