C41 RA in Jobo CP***** processors

[Misko78]

Is it possible? I've read somewhere that C41 RA doesn't have washes between baths. How to deal with rapid 45s bleach, will it kill my dyes if i'm not on time considering pour in-out times. What about 2x45s cascade fix, can i fix for 2minutes instead 2x45s.

 

[Mick Fagan]

That is more or less correct, as the original RA4 process is designed to develop colour paper in 4 minutes, hence the name, Rapid Access 4 minutes (RA4).

This is acheived by each set of roller transport baths having a set of squeegee rollers as the paper leaves the developer bath straight into the bleach/fixer bath. The bleach/fixer bath has the same squeegee type of rollers when the paper emerges into the wash bath.

I have a Durst Printo roller transport desktop processing machine, bought it new some 25 years ago (I think) The squeegee rollers are a soft material that really compresses the paper as it passes through the rollers, effectively making the paper almost dry. It is very effective and very good.

If you are going to do RA4 in a Jobo machine, I would suggest you drop the developer bath when the time is up, then immediately pour in a stop bath of 2% acetic acid (or something similar). This will stop all development within about 15 seconds from the time you start pouring. From then on, you can do the rest of the steps in an unhurried situation.

You can do a wash after the stop bath, I usually did, I think I did two washes of about 30 seconds each, then I put the next bath in a Blix (Bleach Fix combination bath), then when that came out I did the final wash sequence. Which in my case was two loads through the Jobo, then finished in trays using room temperature tap water, then I placed the paper through a paper dryer.

If you can, I would also suggest that you run separate bleach and fix baths, especially for C41. Your bleach, which is usually the most expensive part of the whole process, will last a lot longer. Once you have a bleach/fix bath mixed, that bath will over time slowly degenerate, whether you use it or not. Search this site for bleach and bleach/fix.

The most critical step is the first developer, which is the colour developer. If you are consistent with a Jobo, making the times always the same, you should be fine. Just ensure that once you get going, your first bath is always the same time before you start pouring out, and the same time for when you start pouring the stop bath in. As well as that, maintaining the same temperature on the Jobo. On my own Jobo, I have a tiny piece of tape to indicate where to put the temperature button for both C41 and RA4.

The processes for C41 and RA4 are really straightforward when using a Jobo machine.

Good management.

Mick.

 

[Misko78]

Mike, thanks for the answer, but i asked about C41-RA process chemicals used in minilabs in my Jobo CPE2 with magnet drive to develop film not paper. Bleach is much faster only 45seconds as well as fixer 2x45s, and process is washless.

Color Developing 195 sec.
Bleaching 45 sec.
Fixing 1 45 sec.
Fixing 2 45 sec.
Fixer and Replenisher
Stabilizing 1 20 sec.
Stabilizing 2 20 sec.
Stabilizing 3 20 sec.

That is quite different than Fujihunt C41 xpress chems i've been using.

Color Developing 195 sec.
Stop and Wash 120sec. (according to Fujihunt manual you don't need this step but i added it)
Bleaching 390 sec.
Wash 210 sec.
Fixing 390 sec.
Wash 210 sec.
Stabilizing 60 sec.
Dry

 

[Misko78]

This is what i can obtain really cheap, and i would love to use it if possible.

Tetenal C-41 Colour Developer Replenisher SP45 Low Rate 2 x 5L
Tetenal BL-RA Replenisher 5L
Tetenal C-41 Unicolor Superfix

 

[Mick Fagan]

Misko, oops. Yep, you actually did ask about C41 RA.

I'm only guessing here, but it would seem that the major differences could be the configuration of the machinery; chemicals are probably close to being similar.

Many years ago, something like 27 years ago, I was on-board a cruise ship docked in Melbourne. We were being shown the then new Agfa C41 Process machine that did a process that was wash less. That was pretty much the first time I ever saw a RA C41 process. I believe Kodak then either released, or manufactured their own C41 RA process.

 

[Misko78]

OK epilogue is like this, i've switched to C41RA process completely.
I've bought the following:

Tetenal CD-R SP45 2x5l 102570 + starter 104045
Tetenal Unicolor Superfix FX-VR, 2x3L 102671
Tetenal Bleach BL-RA Ergoline 1x5L 102664 + starter 103333

Mixed the tank chemistry and after i'm finished i replenish the amount needed for films that were developed. I use 150ml of developer per film, so in 1520 tank if i put 2x120 film i use 300ml of developer + 100 more to cover the film completely because i use magnet drive and no lift. In 1520+1530 i use 4 films only with 600ml of developer where i have empty spool so that level of developer tops where there is no film when i pour it in. Results are very good i think noticably better than what i was getting with kit chemistry.

My process goes like this:

2x 0:30 Prewash
3:15 Developer
0:30 Acetic acid stop
1:00 Wash
0:45 Bleash
3:30 Wash
0:45 Fixer
0:45 Fixer
3:30 Wash
1:00 Stabilizer

 

[markbarendt]

OK epilogue is like this, i've switched to C41RA process completely.
I've bought the following:

Tetenal CD-R SP45 2x5l 102570 + starter 104045
Tetenal Unicolor Superfix FX-VR, 2x3L 102671
Tetenal Bleach BL-RA Ergoline 1x5L 102664 + starter 103333

Mixed the tank chemistry and after i'm finished i replenish the amount needed for films that were developed. I use 150ml of developer per film, so in 1520 tank if i put 2x120 film i use 300ml of developer + 100 more to cover the film completely because i use magnet drive and no lift. In 1520+1530 i use 4 films only with 600ml of developer where i have empty spool so that level of developer tops where there is no film when i pour it in. Results are very good i think noticably better than what i was getting with kit chemistry.

My process goes like this:

2x 0:30 Prewash
3:15 Developer
0:30 Acetic acid stop
1:00 Wash
0:45 Bleash
3:30 Wash
0:45 Fixer
0:45 Fixer
3:30 Wash
1:00 Stabilizer

My process with RA chem's:
No prewash (no big deal if you do)
3:15 Developer (this is the only fixed time in the process, the rest are minimums)
1:30 or more Bleach (the C41 process is designed to go straight from developer to bleach, no intermediate steps.)
3:15 or more Wash (typically 2-3 baths, first quick say 0:30ish, then the others for what ever was left to get to 3:15)
3:15 or more Fixer (I used one bath, dual bath is fine)
3:15 or more Wash (typically 2-3 baths, first quick say 0:30ish, then the others for what ever was left to get to 3:15)
1:00 or more Stabilizer

The reason I lean long on time for everything after the developer is to avoid any worry of need to come back. Re-running films is a PITA especially if the films have been cut. There is no downside to the longer times except for the extra time itself. For a commercial lab saving a few seconds here and there is great, for me an extra few minutes in the tank saves me any worry about the bleach, fix, cleanliness, or stabilization.

 

[Misko78]

My process with RA chem's:
No prewash (no big deal if you do)
3:15 Developer (this is the only fixed time in the process, the rest are minimums)
1:30 or more Bleach (the C41 process is designed to go straight from developer to bleach, no intermediate steps.)
3:15 or more Wash (typically 2-3 baths, first quick say 0:30ish, then the others for what ever was left to get to 3:15)
3:15 or more Fixer (I used one bath, dual bath is fine)
3:15 or more Wash (typically 2-3 baths, first quick say 0:30ish, then the others for what ever was left to get to 3:15)
1:00 or more Stabilizer

The reason I lean long on time for everything after the developer is to avoid any worry of need to come back. Re-running films is a PITA especially if the films have been cut. There is no downside to the longer times except for the extra time itself. For a commercial lab saving a few seconds here and there is great, for me an extra few minutes in the tank saves me any worry about the bleach, fix, cleanliness, or stabilization.

So you suggest to skip stop and wash after developer, because obviously bleach is a stop. I've heard that if you stop and wash it won't do any harm and can help save bleach. I also was considering using prolonged bleach and fix times, but, i don't know, I was afraid because these times are so short and using 200-300% more time could harm film. Or i'm totally wrong?

 

[markbarendt]

The most frugal way to use your bleach (and other RA chem's) is replenished.

The working bleach, fix, and stabilizer do not degrade easily. These working solutions can be kept and used indefinitely if replenished to keep the strength normal.

The developer can be replenished too but it only has a shelf life of weeks if not replenished very regularly. If you were running 5-10 rolls a day the replenishment would keep it fresh too for a very long time.

As I said above the developer is the only one that needs an accurate time because devoloping is targeting a certain amount of development, it doesn't go to completion, accurate time and temp ensures proper development. The rest can go considerably longer beacause they "go to completion", when they finish there is nothing more to happen chemically.

 

[Mick Fagan]

Congratulations on what you have achieved so far, it can only get better.

Some thoughts.

By using an acetic acid stop bath directly after the colour developer, you will ensure that your bleach bath will last a lot longer. Bleach is the single most expensive part of the C41 process, anything that preserves this is better for your bank account.

The bleach of C41 processes I have used in the past, had twice the capacity of the fixer bath. By keeping the bleach as clean as possible, one could easily make the bleach bath last the distance.

If you had a fair bit of carry over, which is certainly more possible in a dip-N-dunk system, or small tank processing, then cleanliness of the bleach can possibly be an issue. As most C41 processors in the world were roller transport machines that squeegeed the films between each bath, thereby keeping cross contamination to a minimum, a stop bath was certainly not a requirement. But for home processing of C41, time is not usually an issue. That said, you are using a Rapid Access version.

For some time I monitored a large C41 dip-N-dunk unit, the Kodak technical rep that was often on-site, suggested we change the replenishing to reflect the greater contamination from the colour developer to the bleach bath. Every 3'30" we were usually putting through 6 rolls of film, either 135, 120 or the same area of film in 4x5" or 8x10" sheet film, for about 5 hours a day.

For quite some years in my home darkroom, I pretty much used a single litre of bleach for C41 processing by using a stop bath immediately after the colour developer. This was also helped by re-halogenating the bleach bath by using a simple fish tank aerator for about 15-30 minutes then re-setting the pH using a pH meter.

I must also tell you that Photo Engineer (PE) on this forum suggested that there could be issues with doing this for a long time. Intimating that there are other issues to contend with. Whatever these other issues may be, I myself have had no issues with any of the films that were bleached this way. Some of which I am now re-visiting around 25 years since they were developed.

This does not mean that my films were optimally developed and/or bleached to the Kodak C41 standard, it just means that my films have been developed, bleached and fixed, to a standard that I am extremely satisfied with. Currently, I am getting some very good colour images from these negatives.

A search on this forum should give you more information, there are certainly more than a few threads on re-halogenating C41 bleach.

Mick.

 

[Photo Engineer]

All bleaches are not created equally. An example would be this:

CD, Bleach, wash, etc.. Where bleach is Ferric EDTA or PDTA vs Ferricyanide. In the first hypothetical process, it would work, but in the second, it would give almost total fog. So, it depends on the bleach as to what MUST follow the CD.

PE

 

[Misko78]

Than, should i drop the stop and wash before the bleach?

 

[Photo Engineer]

NO! That helps remove the developing agent.

 

[Misko78]

Thanks PE!!! So no harm to C41RA bleach from acetic acid stop and short 1 min. wash.

 

[Photo Engineer]

No, as long as the wash comes after the stop!

 

[RPC]

1. Standard bleach--stop and wash after CD is optional.

2. Ferricyanide bleach--clearing stop (acetic acid + sulfite) and wash after CD is REQUIRED.