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Color Negative Film Process

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Process Times for C-41 Compatible Chemicals

Process Sequence for Tetenal Mono C-41

Process Sequence for JOBO C-41 Press Kit

Process Information for C-41

Push or Pull Processing for C-41

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Process Times for C-41 Compatible Chemicals

Recommended Process for Kodak C-41, Tetenal C-41 13.5 Liter Kit:

  • Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2500 tanks, '4'/50 for 3000 drums
  • Temperature 38.0°C. (100.4°F)
  1. Pre-Warm 5:00
  2. Developer 3:15
  3. Bleach 6:30
  4. Rinse 3:00 (6x 0:30)
  5. Fixer 6:30
  6. Rinse 5:00
  7. Stabilizer 1:00 (Off processor at room temperature.)
  8. Dry As Needed

Recommended Process for Tetenal Mono C-41 (discontinued during 2001):

  • Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2500 tanks, '4'/50 for 3000 drums
  • Temperature 38.0°C (100.4°F)
  1. Pre-Warm 5:00
  2. Developer 3:15
  3. Bleach-Fix 3:30
  4. Rinse 3:00 (6x 0:30)
  5. Stabilizer 1:00 (formaldehyde-free) (Off processor at room temperature.)
  6. Dry As needed

Recommended Process for Tetenal C-41 Press Kit:

  • Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2500 tanks, '4'/50 for 3000 drums
  • Temperature 38.0°C (100.4°F)
  1. Pre-Warm 5:00
  2. Developer 3:15
  3. Bleach-Fix 6:00
  4. Rinse 3:00 (6x 0:30)
  5. Stabilizer 1:00 (Off processor at room temperature.) 
  6. Dry As needed

Recommended Process for Tetenal C-41 Rapid and Tetenal 5 Liter C-41 kits:

  • Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2500 tanks, '4'/50 for 3000 drums
  • Temperature 38.0°C. (100.4°F)
  1. Pre-Warm 5:00
  2. Developer 3:15
  3. Bleach/fix 4:00
  4. Rinse 3:00
  5. Stabilizer 1:00 (formaldehyde-free) (Off processor at room temperature.)
  6. Dry As Needed

 

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Process Sequence for C-41 Compatible Chemicals

Pre-Warm
A dry 'incubation' of the tank and film allows the tank and film to rise to the process temperature. The film is loaded and in the tank. No water or chemicals are put in the tank. It is rotated in the tempered water bath. This step warms up and stabilizes the temperature of the film, reel, and tank. The pre-warm prevents a chilling of the developer and underdevelopment of the film.

Color Developer
Contrast and density are determined by color development.

Bleach
In the bleach, the metallic silver is converted to silver salts to be removed by the fixing bath.

Rinse
The bleach is removed from the film.

Fixer
In the fixer, the silver converted by the bleach, and all remaining silver salts are removed from the film.

Rinse
The rinse washes out the remaining chemicals and should be at least three minutes long. (Use six changes of water.)

Stabilizer
The stabilizer serves as a wetting agent, preserves the dyes, inhibits bacteria, and hardens the film.

Dry
As needed.

With all rinses, the number of changes of water is most important. We suggest that you change the rinse water at 30-second intervals for the full time of the rinse.

The above description of the process is for Kodak Flexicolor and Tetenal C-41 chemicals. However, in the time charts we have included Tetenal Mono C-41 and Tetenal Press C-41. In these products, the bleach and Fix are combined in a single step called 'Bleach-Fix.' All of the rest of the information applies.

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Process Sequence for Tetenal Mono C-41 and JOBO C-41 Press Kit

Pre-Warm
A dry 'incubation' of the tank and film allows the tank and film to rise to the process temperature. The film is loaded and in the tank. No water or chemicals are put in the tank. It is rotated in the tempered water bath. This step warms up and stabilizes the temperature of the film, reel, and tank. The pre-warm prevents a chilling of the developer and underdevelopment of the film.

Color Developer
Contrast and density are determined by color development.

Bleach-Fix
In this step the silver and silver salts are removed from the film.

Rinse
The rinse washes out the remaining chemicals.

Stabilizer
The stabilizer serves as a wetting agent, preserves the dyes, inhibits bacteria, and hardens the film. 

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Process Information for C-41

There are many different brands and types of C-41 compatible chemistries. All of the major brands have been tested with JOBO processing equipment, and found to produce excellent processing. The process procedures listed below are specifically optimized for rotary processing with JOBO equipment. If you are using chemicals in this list, use the times and procedures in the tables. If you are using a different chemical, find the closest equivalent in the list and use its times to test the process.

Tetenal provides four families of C-41 type chemicals. Tetenal C-41 is a clone type chemical that duplicates the Kodak C-41 Flexicolor process quite closely. It is the only version that is designed for replenishment procedures. Tetenal C-41 Press Kit is an all-powder concentrate ideal for travel and field use. Tetenal C-41 Rapid is designed for the shortest process time possible. The instructions packaged with the Tetenal C-41 type chemical kits may include alternate (not listed below) process procedures for faster, or lower temperature processing, or other special considerations. If you decide you want to utilize these techniques, be sure to read the instructions and understand the limitations that may be imposed by these other procedures. Test all alternative processes for the suitability to your specific needs.

WARNING: Many stabilizers contain formaldehyde, a known carcinogen. Use it only with good ventilation. It is suggested that you use rubber or neoprene gloves and apron, and eye goggles. All stabilizers supplied in the Tetenal C-41 kits are formaldehyde-free.
 
Caution: If reels or tanks are immersed in these solutions, they will eventually cause processing contamination effects. The reels will become difficult to load. Rinsing or cleaning the reels or tanks after processing will not eliminate this problem.

Note:

If you are using stabilizer, you do not need an additional wetting agent. Stabilizer contains a wetting agent. Do not rinse the film after treating it with stabilizer or wetting agent, as this would remove the surfactant included for spot free drying.

Color films contain organic dyes to produce the colors recorded in the film image. These dyes are subject to deterioration or fading with the passage of time. In order for these dyes to be as permanent as possible, a stabilizing bath is used to 'fix' or 'tan' the dyes. Modern improvements in color negative film emulsion technology have produced some emulsions that the manufacturers state do not require this stabilizing treatment to achieve maximum stability in the dye structure. Some 'amateur' films fall into this category. If you want to process a specific film without using a stabilizer, check with the film manufacturer to find out if it requires the stabilizing treatment for maximum post-process dye stability. If you are in doubt about this requirement, it is safest to use the stabilizer treatment. Stabilizer will not harm any C-41 process film. The stabilizers supplied in the Tetenal Rapid C-41 and Mono PK C-41 kits are formaldehyde-free. Unless you use one of these specially formulated stabilizers, the stabilizer will contain formaldehyde (see warning above). Substituting a wetting agent for stabilizer will not preserve the dyes in the film.

With all rinses (except the pre-rinse), change the rinse water at 30-second intervals for the duration of the rinse.

Caution: For most reliable results, do not add a stop-bath and/or rinse between the developer and the bleach (or bleach-fix) steps. Doing so may produce significant increases in contrast and density of the image. The film may not print correctly.

Note:

It is good practice to be consistent in processing procedures. However, it may be useful to know that with the exception of the developer, all steps in the C-41 process (both 2 bath and 3 bath) are 'taken to completion.' That is, once the action of the chemical or rinse has done what it is supposed to (had its effect), further time in the bath or rinse will have no additional benefit or harm. If you are to err in the timing of the process steps other than the developer, it is safer to go longer, not shorter. Be aware however, that very long (over one hour) immersion times in any solution or water could cause excessive softening of the emulsion or other problems, and should be avoided.

All modern color process bleach or bleach-fix chemicals (with the exception of Ilfochrome bleach) requires oxygenation (exposure to oxygen) to perform its function properly and completely. Unlike developer or other chemistries, you should intentionally introduce air

(with its oxygen) to the bleach or bleach-fix. Oxygenation is easily accomplished while diluting the stock solution. Place the bleach or bleach-fix in a larger (about twice the volume of the mixed solution) sealable container. Seal the container and shake vigorously for about thirty seconds. For situations where this procedure is not practical, an inexpensive aquarium 'bubbler' may be used to aerate the solution. Leave the bubbler on for about a half hour. If the bleach or bleach-fix has not been aerated for a week or longer, repeat the procedure before using the chemical.

Caution: Alternate process temperature with resulting changed developer and other steps times, may have unpredictable results. Some films may not print correctly if processed at other than 38°C (100°F).

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Push or Pull Processing for C-41

'Push' process is not normally done with process C-41. If it is necessary to correct for underexposure of the film, add 15% to the developer time for each F-stop of push (doubling the ASA). Pushing film not specifically designated by the manufacturer as 'pushable' may produce a negative that cannot be correctly color balanced in printing. In any case, grain size, the color balance and contrast of push processed C-41 film will be adversely affected to some extent. It is not advisable to 'Pull' process C-41 film. It is better to use the normal processing time for film that has been overexposed. An overexposed and normally processed color negative will print better than a color negative with the development time shortened to correct for overexposure.

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