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Organic means they are made from the chemicals of life. Now the dyes have blossomed and the film is long-lasting. The fixer removes most all traces of silver from the film. The fixer is a solvent for silver halogens. This act sets up the film for fixing (to render permanent). This solution seeks metallic silver and changes it back to a silver halide. This makes of total of 5 colored images.Īs the C-41 film emerges from the color developer, the colors are veiled by the metallic silver images, and the film has residual unexposed and thus undeveloped silver crystals.Ī bleach to the rescue! The word bleach is deceiving. The mask forms two positive colored images superimposed on the three negative colored images. The mask is not uniform as to its density. Its purpose is to bolster the magenta and yellow dye image. This forms the orange mask of the C-41 film. To correct these deficiencies, the leuco magenta and the leuco cyan are tinted. The yellow image is fine-looking, the magenta image is fair, and the cyan image is actually substandard. The film also contains a cyan image, a magenta image and a yellow image. The film also contains tufts of metallic silver forming a black & white image in each emulsion. They now blossom into cyan, magenta and yellow dyes based upon their emulsion layer.Īt this stage the film contains unexposed and thus undeveloped silver salts. Those dye globules adjacent to tarnished tuffs of metallic silver are caused to unite with the missing dye ingredient. All three are missing the same ingredient which is present in the color developer. Being incomplete, they are said to be in a leuco state, (Greek for white). The tufts of silver are caused to tarnish.ĭispersed in each emulsion are incomplete oily globules of dye - cyan dye in the red sensitive emulsion, magenta in the green emulsion, and yellow in the blue emulsion. As the tufts of silver materialize, they will be acted upon by oxygen dissolved in the waters of the developer. This silver creates the black and white image. Remaining is a tuft of opaque metallic silver. The halogen is dissolved away in the waters of the developer. This latent image is proportional to scene brightness and coloration.Īs the film develops, developing agents seek out exposed crystals and reduce them to metallic silver and a halogen. The C-41 film, when exposed in the camera, receives a latent (Latin for hidden) image. Color films consist of multiple emulsion coats, each doctored so they become light-sensitive to one of the three light primary colors, which are red, green, and blue. They are imbedded in gelatin to form an emulsion.
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These halogens are iodine, chlorine, and bromine. These are compounds of silver combined with a halogen (Swedish for salt maker). Modern color films contain miniature light-sensitive crystals. Separating bleach and fix is not a requirement is a home darkroom setting. This is true because paper prints can be reprinted if something goes wrong, film if ruined is usually not salvageable.
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This works out OK but separate would be better. The color paper developing process did combine the bleach and the fix. It is not economically feasible to mass process without keeping the bleach and fix as separate chemical baths. In other words, fluids are treated, re-used and then finally discarded safely. This is accomplished by on-line electrolytic devices.īesides all the problems of keeping the solutions at specification, the lab must sewer or haul-away to an licensed waste facility. As this fluid works to remove silver salts and metallic silver, it’s silver level must be controlled. The EDTA (red) bleach is iron based and its operation depends on the level of iron oxidation. The bleach must not only be replenished, it must be aeriated. Test strips are measured and graphed with high precision.Ĭhemical tanks are filled with a tank formula and replenished, based on the graphs with a specialized replenished formula. Test films are run interlaced with customer film. Now we are talking, automatic temperature control, both heating and refrigeration. That being said, when you process at this volume, the chemistry must have an indefinite life. Additionally, the color balance of outputted prints was topnotch. Regardless of what you think, the vast majority outputted a top quality product, The standards were plus/minus 1/6 of an f-stop. Such labs as these were duplicated in countless locals worldwide. Each was sized to handle 20,000 rolls of color film a day. I was technical manager for 7 such labs in the Southeast United States. The C-41 and E-6 processes and their cine counterparts evolved in an era where giant regional processing labs were the norm.