Color
Negative Film Process
Go to:
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
Back to Top
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)
- Pre-Warm 5:00
- Developer 3:15
- Bleach 6:30
- Rinse 3:00 (6x 0:30)
- Fixer 6:30
- Rinse 5:00
- Stabilizer 1:00 (Off processor at room temperature.)
- 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)
- Pre-Warm 5:00
- Developer 3:15
- Bleach-Fix 3:30
- Rinse 3:00 (6x 0:30)
- Stabilizer 1:00 (formaldehyde-free) (Off processor at room
temperature.)
- 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)
- Pre-Warm 5:00
- Developer 3:15
- Bleach-Fix 6:00
- Rinse 3:00 (6x 0:30)
- Stabilizer 1:00 (Off processor at room
temperature.)
- 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)
- Pre-Warm 5:00
- Developer 3:15
- Bleach/fix 4:00
- Rinse 3:00
- Stabilizer 1:00 (formaldehyde-free) (Off processor at room
temperature.)
- Dry As Needed
Back to Top
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.
Back to Top
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.
Back to Top
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).
Back to Top
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.
Back to Top
If you have any questions, contact us utilizing one of the
following methods:
Equipment or Processing Questions:
- Phone: Customer Service Department (734) 205-9421
e-mail: tech@jobo-usa.com
Repair Questions:
- Phone: Repair Department (734) 205-9420
- e-mail: repair@jobo-usa.com
- Telephone (734) 677-6989
- Fax: (734) 677-6963
-
- Postal address
- P.O. Box 3721, Ann Arbor, MI 48106
- Shipping Address
- 4401 Varsity Drive, Suite D, Ann Arbor, MI 48108
- Electronic mail
- Sales: sales@jobo-usa.com
- Equipment & Processing Questions: tech@jobo-usa.com
Repair Information: repair@jobo-usa.com
- Shipping or Billing Questions: help@jobo-usa.com
Webmaster: webmaster@jobo-usa.com
-
Back to Top