There are a lot of posts and questions on this forum about different bleaches in the C-41 (and ECN2) process.
I think it would be helpful to organize this.
In my post in another thread, I promised to write more about BLEACH baths in both Bellini C-41 and ECN2 kits.
www.photrio.com
Both Bellini kits are available for sale in Europe and the U.S. The advantage of these kits is that they offer separate BLEACH baths, rather than a single BLIX bath.
I've used both kits successfully.
Whenever I develop color films at home, both C-41 and ECN2, I use a STOP bath after developing.
I never use BLIX.
When I used the ADOX C-TEK C-41 kit, I converted the BLIX from that kit to a BLEACH bath, per @Rudeofus's recommendation.
www.photrio.com
Currently, I use professional lab chemicals, FUJI HUNT Environeg AC Developer & Replenisher LV 60, with Fuji starter,
and FUJI HUNT C-41 Negacolor RA Fixer & Replenisher (the fixer does not require a starter)
Wanting to save a bit, I didn't buy standard C-41 bleach, but used a potassium ferricyanide-based bleach bath instead.
Of course, to avoid problems, I used a stop/cleaning bath after the developer, before the bleach bath.
This recipe follows:
www.photrio.com
My C-41 development procedure looked like this:
DEVELOPER -> STOP/CLEAN Bath -> Rinse -> BLEACH -> Rinse -> FIXER -> Rinse -> STAB
My results are very good and repeatable.
You can add 10g of sodium sulfite to the rinse bath after BLEACH – this was recommended by our beloved PE.
After such a cleaning bath, of course rinse the film in water before the fixer.
Link to PE's post on this forum:
www.photrio.com
I forgot about this at some point, but it didn't affect my results. It could possibly affect the archival life of the negatives.
Since I'm running low on potassium ferricyanide, I've decided to switch to the original Kodak-approved BLEACH baths.
Of course, I will still use STOP after the developer, but I will not have to clean with sodium sulfite anymore.
However, before I bought the professional C-41RA AC FUJI Bleach, I noticed that I still had two unopened Bellini kits – a C41 kit and an ECN2 kit.
I decided to use these kits - especially the BLEACH baths included in them.
The assumption is that the chemistry used in the C-41 process is standardized. Therefore, you can easily apply the following principle:
The principle of interchangeability.
You can use developer from a KODAK C-41 set, ADOX C-TEK C-41, Bellini C-41, or other developers based on color developing agent CD-4.
You can then use a BLEACH bath from a completely different C-41 set, and fix the film in a fixer from a different C-41 set, or even use any B&W fixer if necessary.
Ideally, the fixer should have a neutral or slightly alkaline pH, but with modern C-41 films, even an acidic fixer should not damage the colors on the negative.
You can also use C-41 BLEACH in the ECN2 process without any problems (this also applies to the FIXER).
The key issue was the chemical composition of the BLEACH bath in both Bellini kits.
We know that three basic chemical substances are currently used in C-41 kits:
1. Ferric PDTA
2. Ferric EDTA (the weakest whitening agent)
2. Potassium ferricyanide (very rarely, probably only in powder kits)
In the case of Bellini kits, it's impossible to determine the substance used in the bleach.
I thoroughly reviewed the SDS (formerly called MSDS) documents for both kits and found nothing.
So I emailed Bellini directly and received a response from Mr. Filippo, who was very kind, friendly, and helpful.
Below are the questions and answers from the email.
Question:
Is the chemical composition of the bleach bath in your C-41 kit the same as the ENC2 kit?
Answer:
No the solutions are different:
- ECN2 bleach is the SR33 Eastman Kodak bleach formulation, that is public formula from Kodak.
- The C41 is the RA bleach, the rapid one that Kodak used on minilabs
My note: SR33 Eastman Kodak bleach formulation is based on Ammonium Feric PDTA.
KODAK Chelating Agent No. 1 is PDTA.
www.photrio.com
Question:
Why do you recommend discarding the ECN2 kit's bleach bath after two weeks of mixing the chemicals?
My personal experience tells me that PDTA-based or EDTA-based bleach can last almost forever.
Answer:
The ECN2 kit the limiting factor is the developer. The bleach have a bit longer life than the developer but solutions must be replenished.
The kit is used till exhaustion and not replenished so we balanced chemicals for this purpose even if some chemicals keep residual capacity
but not enough to change only the developer and go ahead with all the others chemicals.
Different is the C41 where the bleach is double the endurance of the developer and we sell singular developer bottle to double the capacity of the kit,
in addition the working tank solution and the replenisher on C41 are similar. On ECN2 are different, the working tank solution is more "light"than the replenisher.
PDTA/EDTA based bleach can last almost forever if unused, is does not deteriorate after opening. The bleaches lose functionality after use, not after mixing or if opened.
In opposite the developer lose its functionality after use and after opening.
Question:
I can bleach about 50 films and regenarate bleach by vigorously shaking the bottle of solution to oxygenate it...
Answer:
YES, correct, the oxidation is essential for the bleaches to oxidize Iron from Ferrous (II) to Ferric (III)
About the capacity: The bleach life is longer than developer for sure and requires oxidation.
But when bleaching, films release components that affect badly bleaching action and limit the functions of the bleach.
So 50 films for 1 liter I guess could be overestimate, but is not excluded that you can try lenghtening bleaching times.
Anyway if the film is poorly bleached you can recover the film bleaching again with fresh one solution, so is reversible!
You can try also with C41-RA bleach (still using the ECN2 bleaching times) that is very strong but we didn't tested the endurance.
Anyway Kodak do not consider the ECN2 process something to be run till exhaustion, but must be replenished.
So at Bellini Foto, we tested it to allow users to have a good chance to develop motion picture films at home or in small labs, using the same professional products in small scale
(not strange substitutes or creative alternatives made by others).
Question:
Of course, both in the case of the C-41 and ECN2 processes, I always use a STOP bath and then rinse with water to avoid contamination of the bleach bath with the developer.
Answer:
It has a good effect, but is not so crucial about the bleach life, for sure is a good practice.
Also if you process 120 rollfilm and sheet films on C41 is very important to add a stop bath step to avoid any kind of problem on developing density zone uniformity.
Summary: I have presented here my conversation with a person representing a well-known manufacturer of photographic chemicals.
All of my statements in this thread are based on my personal experience, as well as the opinions of experts on this forum, which I have successfully implemented.
If yours differ, please share them here. Please, no hate.
I think it would be helpful to organize this.
In my post in another thread, I promised to write more about BLEACH baths in both Bellini C-41 and ECN2 kits.
Fuji X Press 5L C41 info sheet
Hi. This looks like the right forum for me. First post here. Ive been looking all over the internet and I can't find a technical info sheet for the Fuji C41 X press 5L kit. Im trying to figure out if the capacity of the developer is the same as the Kodak kit or not. Especially, I'm trying to...
www.photrio.com
Both Bellini kits are available for sale in Europe and the U.S. The advantage of these kits is that they offer separate BLEACH baths, rather than a single BLIX bath.
I've used both kits successfully.
Whenever I develop color films at home, both C-41 and ECN2, I use a STOP bath after developing.
I never use BLIX.
When I used the ADOX C-TEK C-41 kit, I converted the BLIX from that kit to a BLEACH bath, per @Rudeofus's recommendation.
Converting C-41/E-6 BLIX into Separate Bleach and Fixer
1 Introduction Many C-41 and E-6 kits come with BLIXes to remove silver. These BLIXes sometimes don't work all that well, and some of the BLIX concentrates have limited shelf life. The main purpose of this document is to provide a brief...
www.photrio.com
Currently, I use professional lab chemicals, FUJI HUNT Environeg AC Developer & Replenisher LV 60, with Fuji starter,
and FUJI HUNT C-41 Negacolor RA Fixer & Replenisher (the fixer does not require a starter)
Wanting to save a bit, I didn't buy standard C-41 bleach, but used a potassium ferricyanide-based bleach bath instead.
Of course, to avoid problems, I used a stop/cleaning bath after the developer, before the bleach bath.
This recipe follows:
Sodium Sulfite clearing bath in ecn2 process
I have been using vision 3 film for about three years. I mix my own chemistry. Until recently I never used Na Sulfite as a clearing bath after the stop or bleach step. I didn’t see a sulfite clearing step in the protocols published by Kodak. But after reading some old posts that suggested...
www.photrio.com
My C-41 development procedure looked like this:
DEVELOPER -> STOP/CLEAN Bath -> Rinse -> BLEACH -> Rinse -> FIXER -> Rinse -> STAB
My results are very good and repeatable.
You can add 10g of sodium sulfite to the rinse bath after BLEACH – this was recommended by our beloved PE.
After such a cleaning bath, of course rinse the film in water before the fixer.
Link to PE's post on this forum:
C41 Bleach: Pot.Ferricyanide Vs. Ammonium Ferric EDTA
Hallo everybody, there are many advantages by working with c41 chemicals when you not use bleach and fixer as one solution. Also named as "Bix" - just like, for example, the tetenal c41 home-kits contains. This is offen discused here on APUG. One can find so many tread as one would like to...
www.photrio.com
I forgot about this at some point, but it didn't affect my results. It could possibly affect the archival life of the negatives.
Since I'm running low on potassium ferricyanide, I've decided to switch to the original Kodak-approved BLEACH baths.
Of course, I will still use STOP after the developer, but I will not have to clean with sodium sulfite anymore.
However, before I bought the professional C-41RA AC FUJI Bleach, I noticed that I still had two unopened Bellini kits – a C41 kit and an ECN2 kit.
I decided to use these kits - especially the BLEACH baths included in them.
The assumption is that the chemistry used in the C-41 process is standardized. Therefore, you can easily apply the following principle:
The principle of interchangeability.
You can use developer from a KODAK C-41 set, ADOX C-TEK C-41, Bellini C-41, or other developers based on color developing agent CD-4.
You can then use a BLEACH bath from a completely different C-41 set, and fix the film in a fixer from a different C-41 set, or even use any B&W fixer if necessary.
Ideally, the fixer should have a neutral or slightly alkaline pH, but with modern C-41 films, even an acidic fixer should not damage the colors on the negative.
You can also use C-41 BLEACH in the ECN2 process without any problems (this also applies to the FIXER).
The key issue was the chemical composition of the BLEACH bath in both Bellini kits.
We know that three basic chemical substances are currently used in C-41 kits:
1. Ferric PDTA
2. Ferric EDTA (the weakest whitening agent)
2. Potassium ferricyanide (very rarely, probably only in powder kits)
In the case of Bellini kits, it's impossible to determine the substance used in the bleach.
I thoroughly reviewed the SDS (formerly called MSDS) documents for both kits and found nothing.
So I emailed Bellini directly and received a response from Mr. Filippo, who was very kind, friendly, and helpful.
Below are the questions and answers from the email.
Question:
Is the chemical composition of the bleach bath in your C-41 kit the same as the ENC2 kit?
Answer:
No the solutions are different:
- ECN2 bleach is the SR33 Eastman Kodak bleach formulation, that is public formula from Kodak.
- The C41 is the RA bleach, the rapid one that Kodak used on minilabs
My note: SR33 Eastman Kodak bleach formulation is based on Ammonium Feric PDTA.
KODAK Chelating Agent No. 1 is PDTA.
Can EDTA replace PDTA in ECN-2 bleach?
Hello everyone,I recently researched ecn-2 to process movie film.In the official SR-33, SB-34, and SR-35 bleaching formulations, it can be seen that KODAK Chelating Agent No. 1 is actually PDTA.I asked the PDTA price and found it too expensive to bear,About $70 per 100 grams.I want to know if I...
www.photrio.com
Question:
Why do you recommend discarding the ECN2 kit's bleach bath after two weeks of mixing the chemicals?
My personal experience tells me that PDTA-based or EDTA-based bleach can last almost forever.
Answer:
The ECN2 kit the limiting factor is the developer. The bleach have a bit longer life than the developer but solutions must be replenished.
The kit is used till exhaustion and not replenished so we balanced chemicals for this purpose even if some chemicals keep residual capacity
but not enough to change only the developer and go ahead with all the others chemicals.
Different is the C41 where the bleach is double the endurance of the developer and we sell singular developer bottle to double the capacity of the kit,
in addition the working tank solution and the replenisher on C41 are similar. On ECN2 are different, the working tank solution is more "light"than the replenisher.
PDTA/EDTA based bleach can last almost forever if unused, is does not deteriorate after opening. The bleaches lose functionality after use, not after mixing or if opened.
In opposite the developer lose its functionality after use and after opening.
Question:
I can bleach about 50 films and regenarate bleach by vigorously shaking the bottle of solution to oxygenate it...
Answer:
YES, correct, the oxidation is essential for the bleaches to oxidize Iron from Ferrous (II) to Ferric (III)
About the capacity: The bleach life is longer than developer for sure and requires oxidation.
But when bleaching, films release components that affect badly bleaching action and limit the functions of the bleach.
So 50 films for 1 liter I guess could be overestimate, but is not excluded that you can try lenghtening bleaching times.
Anyway if the film is poorly bleached you can recover the film bleaching again with fresh one solution, so is reversible!
You can try also with C41-RA bleach (still using the ECN2 bleaching times) that is very strong but we didn't tested the endurance.
Anyway Kodak do not consider the ECN2 process something to be run till exhaustion, but must be replenished.
So at Bellini Foto, we tested it to allow users to have a good chance to develop motion picture films at home or in small labs, using the same professional products in small scale
(not strange substitutes or creative alternatives made by others).
Question:
Of course, both in the case of the C-41 and ECN2 processes, I always use a STOP bath and then rinse with water to avoid contamination of the bleach bath with the developer.
Answer:
It has a good effect, but is not so crucial about the bleach life, for sure is a good practice.
Also if you process 120 rollfilm and sheet films on C41 is very important to add a stop bath step to avoid any kind of problem on developing density zone uniformity.
Summary: I have presented here my conversation with a person representing a well-known manufacturer of photographic chemicals.
All of my statements in this thread are based on my personal experience, as well as the opinions of experts on this forum, which I have successfully implemented.
If yours differ, please share them here. Please, no hate.
