K-14 process

{{multiple image |align=right |direction=horizontal |title=Kodachrome film schematic and exposure

|image1=K-14M step 00.svg |caption1=Unexposed film cross-section

|image2=K-14M step 01.svg |caption2=Exposure, showing sensitization of different layers according to red, green, and blue components of visible light}}

The cross-section of Kodachrome film consists of layers which are, from top-to-bottom: blue sensitive (of which the non-sensitized portions will be dyed yellow), yellow filter, blue-green sensitive (dyed magenta), blue-red sensitive (dyed cyan), acetate base, rem-jet anti-halation backing.{{cite journal |url=https://archive.org/details/journalofsociety25socirich/page/64/mode/2up |title=The Kodachrome process for amateur cinematography in natural colors |date=July 1935 |author1=Mannes, L.D. |author2=Godowsky Jr, L. |author1-link=Leopold Mannes |author2-link=Leopold Godowsky Jr. |journal=Journal of the Society of Motion Picture Engineers |volume=25 |number=1 |access-date=24 August 2023 |pages=65–68|doi=10.5594/J05399 }}

The blue-green and blue-red sensitive layers are primarily sensitive to green and red light, respectively, but are sensitive to blue light as well. The yellow filter layer is added to prevent blue light from penetrating to these layers during exposure.

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class="wikitable" style="font-size:100%;text-align:left;" |+K-14 processing cycle ! Step !! Action !! Schematic !! Description
1	Backing removal | rowspan=3 | File:K-14M step 02.svg | An alkaline bath softens the cellulose acetate phthalate binder. A spray wash and buffer removes the rem-jet anti-halation backing.
2	First Developer | All exposed silver halide crystals are developed to metallic silver via a PQ (phenidone/hydroquinone) developer. The yellow filter layer becomes opaque because it has a combination of Lippmann emulsion (very tiny grains) and Carey Lea silver (metallic silver particles that are small enough that they are yellow rather than gray.)
3	Wash | Stops development and removes the PQ developer.
4	Red light re-exposure through the base | rowspan=1 | File:K-14M step 03.svg | This makes the remaining undeveloped silver halide in the cyan layer developable.
5	Cyan developer | rowspan=2 | File:K-14M step 04.svg | The solution contains a color developer and a cyan coupler. These are colorless in solution. After the color developer develops the silver, the oxidized developer reacts with the cyan coupler to form cyan dye. The dye is much less soluble than either the developer or the coupler so it stays in the blue-red sensitive layer of the film.
6	Wash |
7	Blue light re-exposure from the top | rowspan=1 | File:K-14M step 05.svg | This makes the remaining undeveloped silver halide grains in the blue sensitive layer (the yellow layer) developable. The now opaque yellow filter layers prevents the blue light from exposing the magenta layer (the green sensitive layer, which is also sensitive to blue light). It is important to avoid stray printing light exposing the film base of film.
8	Yellow developer | rowspan=2 | File:K-14M step 06.svg | Analogous to the cyan developer.
9	Wash |
10	Magenta developer | rowspan=2 | File:K-14M step 07.svg | This contains a chemical fogging agent that makes all of the remaining undeveloped silver halide developable. If everything has worked correctly, nearly all of this silver halide is in the magenta layers. The developer and magenta coupler work just like the cyan and yellow developers to produce magenta dye that is insoluble and stays in the film.
11	Wash |
12	Conditioner | rowspan=2 | File:K-14M step 08.svg | Prepares the metallic silver for the bleach step.
13	Bleach | Oxidises the metallic silver to silver halide. The bleach (ferric EDTA) must be aerated. The former ferricyanide bleach did not require aeration and did not require a conditioner.
14	Fix | rowspan=4 | File:K-14M step 09.svg | Converts the silver halide to soluble silver compounds which are then dissolved and washed from the film.
15	Wash | Washes the fixer out of the film.
16	Rinse | Contains a wetting agent to reduce water spots.
17	Dry |

The result is three different color records each with the appropriate dye, just like other color films. The original Kodachrome process in 1935 used dye bleaches and was a far more complex process; the dyes themselves were unstable and faded at high temperature. Although the formulae have changed over the years, the basic process steps have followed a similar pattern since the introduction of "selective re-exposure" Kodachrome in 1938.{{cite book |url=https://archive.org/details/twentiethcentury0000peni |title=Twentieth Century Colour Photographs: The complete guide to processes, identification & preservation |author=Pénichon, Sylvie |chapter=5: Dye Coupling (or Chromogenic) Processes |publisher=Thames & Hudson |date=2013 |location=London |isbn=978-0-500-51719-2 |url-access=registration}}{{rp|163;189}}

{{Reflist|refs=

{{cite web

|title = Processing Steps – Processing Kodachrome Film (PDF)

|publisher = Eastman Kodak Company

|date = 2000

|access-date = 1 March 2009

|url = http://www.kodak.com/global/plugins/acrobat/en/service/Zmanuals/z50_03.pdf|archive-url = https://web.archive.org/web/20030420202317/http://www.kodak.com/global/plugins/acrobat/en/service/Zmanuals/z50_03.pdf|url-status = dead|archive-date = 2003-04-20}}

{{cite book|title=Catalog of Copyright Entries. Third Series: 1971: July-December|quote=[reference to another publication] "Manual for procesing Kodachrome II film and Kodachrome-X film (process K-12)}}

{{cite web|title=Process K-14 sequence with cross-sections|url=http://www.randrews4.com/ProcessK-14.pps|format=pps|access-date=8 October 2016}}

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• [https://web.archive.org/web/20030420202317/http://www.kodak.com/global/plugins/acrobat/en/service/Zmanuals/z50_03.pdf Kodak: Processing Kodachrome film]
• [http://www.randrews4.com/ProcessK-14.pps K-14 Process Demonstration]

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Category:Photographic film processes