K-14

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Kodachrome II - slide reversal film
Mailing pouch containing Kodachrome films for submission to a Kodak laboratory for K-14 processing. By cutting off the marked corner, you informed that the slide film should not be framed.

The process K-14 is a photographic development process of Kodak for development of Kodachrome -Umkehrfilme. The name stands for the development of K odachrome in 14 chemical baths.

In contrast to other color films, Kodachrome films did not contain any color couplers (dyes); Instead, these were contained in three individual developer solutions, with which the three basic colors were built up one after the other in three individual reverse development steps. The film itself therefore - in contrast to the other color films - was more like three black and white films with color filters placed one on top of the other.

Due to its complexity, the K-14 process could not be carried out alternatively in the home laboratory or in any specialist shop, but required the submission to a large Kodak laboratory. The film development was included in the purchase price.

procedure

The process flow has been optimized several times over the decades.

The variant K-14M ​​("Minilab") had been developed by Kodak in the 1990s for the K-Lab development machine, which was intended for decentralized, computer-controlled development, for example in a photo shop, but was unable to establish itself due to the poor quality of the results .

The work steps are as follows:

  1. Remove the antihalation layer on the back of the film with an alkaline solution, wipe with water
  2. First development of three black and white negative images, one on top of the other, one for each basic color, whereby silver halide exposed in the camera is converted to silver
  3. Wash to rinse out the developer
  4. Post-exposure of the cyan layer with red light through the rear side in order to expose remaining light-sensitive silver halide in the layer
  5. Development of the cyan layer with a developer which also contains the color coupler for cyan and which combines with the silver halide which has developed into silver
  6. Wash to stop and rinse out the developer
  7. Post-exposure of the yellow layer to blue light through the emulsion side to expose remaining photosensitive silver halide in the layer
  8. Development of the yellow layer with a developer which also contains the color coupler for yellow and which combines with the silver halide developed to silver to form a yellow positive image
  9. Wash to stop and rinse out the developer
  10. Development of the magenta layer with a developer which also contains the color coupler for magenta and which develops the remaining light-sensitive silver halide in the film to silver, which is all in this layer and has not yet been developed
  11. Wash to stop and rinse out the developer
  12. Conditioner to prepare for the bleach bath
  13. Bleaching oxidizes the silver back to silver halide
  14. Fixing to remove the silver halide that is undesirable after color formation
  15. Washing to remove the fuser
  16. Rinse with anti-water stain agent
  17. dry

The result is three main layers of color that together create a positive color image.

use

In addition to its photographic use, Kodachrome K40 reversal film was for decades the standard film material for working with Super 8 film cameras. In this role, it was later replaced by Kodak's Ektachrome-64T material, which can be developed in the less complex E-6 process.

The last K-14 development laboratory in Europe in Lausanne , Switzerland, was shut down in autumn 2006. Since then, worldwide development has only been possible in the Dwayne's Photo laboratory in the USA, and Kodak even had the films sent in developed there on order. On December 30, 2010, this last K-14 machine at Dwayne's was also taken out of service, as Kodak had not been producing the chemicals required for the process in reasonable quantities since 2009 due to a lack of demand. More information can be found in the article Kodak Kodachrome .

Web links

Individual evidence

  1. ↑ K-Lab Processors Improve Kodachrome Film Processing , Kodak press release, accessed June 28, 2014