Separate Bleach and Fix for RA4?

[David Lyga]

One nice thing about separate bleach and fix for C41 is the better keeping properties. You can stretch the bleach quite far by regenerating it, making the most of the expensive ferric sodium EDTA.

Can this be done with RA4?

Only commercial blix I can find here comes in pre-mixed 10L ektacolor bottles. Well above my yearly printing frequency and I'm assuming it doesn't keep for super long after open.

Scratch mixing would be nice but if I have to keep dumping out precious ferric ammonium EDTA the math doesn't work that well.

PS: Could C41 bleach and fix work for RA4? I know that C41 uses a different EDTA salt but PE did once post an old experimental formula for RA4 blix with ferric sodium EDTA. I can live with experimental for paper.

I have always used the pot ferr / fix bleach with RA4 paper, always fixing before and then giving a good rinse before the blix. Again mix just before using as it starts deteriorating 15 minutes after the mixing. The strength of these component can easily be one half those used for film, as the color paper responds much more quickly. - David Lyga

 

[koraks]

That is how it usually goes with marketplace products.

Not sure if I agree. Many instances of backwards compatibility are just a matter of luck. Note that PE never said it doesn't work. He pointed out that it's unverified/uncertain, especially in terms of long term stability.

 

[koraks]

always fixing before and then giving a good rinse before the blix.

Why fix before Blix?

 

[Photo Engineer]

I would guess that David is right about EK anticipating this sort of use.

PE

 

[David Lyga]

You know, I had experienced problems with the black blix that is in use today. But why fix first? Because of this (I am not a chemist but an astute observer of what chemistry does!!!): For some reason if even a molecule of developer is left in the film that pot ferr bliix becomes orange and fogs the film. To be absolutely certain, I fix first, (but even then there is a tiny bit of developer within the emulsion). After fix, full room light can be on and I wash for a couple of good rinses. THEN, and ONLY THEN, can my blix be applied. The film clears rather quickly (unlike my many experiences with that black blix) depending upon how strong the pot ferr blix is. My blix formula (stated by volume in ml, NOT mass) is made up of fixer (Half film strength) and bleach (3 ml potassium ferricyanide makes 200 ml of bleach and lasts indefinitely even in a half filled bottle. (I use PET plastic.). Then, just before use, mix one part of my diluted (fresh only please, not reused) fixer with one part of bleach and you are good to go. I would not use anything else. No more need to 'oxidize' the black bleach. And my way is readily available and cheap (matching David Lyga's inherent frugality!!!)

EVERYTHING I DO IS 'ONE SHOT'. I reuse NOTHING. That prevents problems with contamination. You do not have to use a full tank of fixer" you can simply turn the reel on its side and, like a Ferris wheel, turn it around and around in the dark while you fix the film. In other words, use common sense when applying my principles. PE is great (and needed) for theoretical perfection but David Lyga has his place within the pragmatic realm where deviance is sometimes welcomed and refreshing. - David Lyga

 

[koraks]

Ah I see, that makes sense. Yes, developer + ferricyanide will generate dichroic fog. Thorough rinsing and/or a sulfite bath should do the trick. If the fix-Blix procedure works for you, that's fine of course. It makes sense, even if there are several (not necessarily better) ways to skin that particular cat.

 

[David Lyga]

Ah I see, that makes sense. Yes, developer + ferricyanide will generate dichroic fog. Thorough rinsing and/or a sulfite bath should do the trick. If the fix-Blix procedure works for you, that's fine of course. It makes sense, even if there are several (not necessarily better) ways to skin that particular cat.

I cannot refute you but my method is easy and not cumbersome. That are differences within this broad panoply of chemical answers. That what the forum is all about. My way works and is both easy and inexpensive.

To remove any ambiguities: My FIX is with regular film fixer (although Kodak makes a dedicated Flexicolor fixer which is great). I have not had any problems, however, with using standard fixer for both color and B&W. For film (either B&W or color) I use the fixer at half strength and have had no problems. You have to understand that Kodak assumes that you will be reusing chemicals and gear their 'requirement' to take up the slack due to that and to procedural sloppiness (David Lyga is not 'sloppy'). My blix, although it uses half strength fixer and my pot ferr bleach, can even be diluted AGAIN if you are patient with time (maybe eight to ten minutes. Since I do one shot with everything I dilute heavily. To re-iterate what I have said in the past, I develop C-41 film for 8 minutes (at 100F) diluting Kodak Flexicolor (actually KF 12-1532753) a whopping 1 + 9. That turns a 25 US gallon size into a 250 US gallon size. Of course, I do not mix everything at once, but, instead, measure the chemicals for what is needed. For example, to make one liter (mixed per Kodak) take 80 ml of A, 9.4 ml of B, 10 ml of C and add WTM 1000. This is what I call a stock C41 developer (even though it is precisely what Kodak calls for in the actual development. I then dilute this stock 1 + 9 and I get great negatives. Storage of the stock in PET plastic (filled to the brim by either squeezing certain PET bottles) or adding glass marbles does this well. I can store this for years and years, despite the naysayers out there who 'know' otherwise. - David Lyga

 

[koraks]

Yes, I've read your posts about dilute c41 and to be honest, I've never dared try it. So I certainly cannot argue with your experience. Am I skeptical? Certainly. But I have no facts to back up my skepsis! If it works for you consistently and reliably and has so for years, I couldn't (and wouldn't!) even begin to argue that you're "wrong". The same with your apprach to RA4. It's nothing like mine, but if it works, it works.

 

[Rudeofus]

A while back I suggested using Agfa 304 as stop/fix bath for RA-4, with the aim of not just stopping dev action, but relieving the BLIX of extra silver as well. However, in the meantime I have come to the conclusion, that a stop/fix bath is not such a good idea. If you look at regularly developed&fixed paper after you bleach it, there is a solid brown stain left behind where there should be only AgBr. This brown stain is Silver Sulfide, which is formed when thiosulfate interacts with silver and silver halide. The same kind of Silver Sulfide can be formed, if you fix RA-4 before BLIXing it. Silver Sulfide is long term stable, so it won't hurt stability, but I would assume that colors could be off.

@color developer, ferricyanide and fog: this is most definitely not dichroic fog. It is regular image fog! Ferricyanide will oxidize CD-3/CD-4, and the oxidized color developer molecules will then react with embedded dye couplers.

 

[AgX]

As C41 film isn't rated for Ferricyanide bleach, there's no guarantee that dyes that are exposed to Ferricyanide will remain intact in the long run though immediately after bleaching the film they may look fine.

There should not be a postprocess dye degradation due to the Bleach, assuming the Bleach compound being washed off.

Or am I simplifying things?

 

[Photo Engineer]

Read my post above on this subject.

Also, please note that color products are designed to give the best color with a defined sequence of pH and a final correct or optimum pH.

PE

 

[David Lyga]

Here are a few frames that I took right outside of my apartment and processed a couple of hours ago, using my dilution of 1 + 9. - David Lyga
Film is Fuji Super G + expired 1998 and ISO is 100. Has NOT lost speed (unlike '400' films!!!)

 

[Raghu Kuvempunagar]

Also, please note that color products are designed to give the best color with a defined sequence of pH and a final correct or optimum pH.
PE

For C41 film, is this the right pH sequence?

Pre-soak - ?, developer - 10.4 [1] or 10.00±.05 [4], bleach - 6.5 [2,3,4], wash - ?, fix - 6.5 [4,5], wash - ?, stabiliser - ?

And if one needs to add a stop after the developer, should the pH of the stop also be around 6.5?

[1] Post #7 in the thread https://www.photrio.com/forum/threads/help-needed-with-laut-c-41-developer.38261/
[2] Post #2 in the thread https://www.photrio.com/forum/threads/c41-bleach-formula.12343/
[3] Post #122 in the thread https://www.photrio.com/forum/threads/c41-formulas.142062/page-5
[4] http://www.chemistry.hitechemall.com/support/diagnostics/diagflm.htm
[5] Post #1 in the thread https://www.photrio.com/forum/attachments/c41-original-fix-jpg.167987/

 

[Rudeofus]

AFAIK C-41 bleach is at pH 4 - 5, not at pH 6.5. Stabilizer pH will be all over the place, but with such weak buffering, that it has no effect. Fixer is last well buffered process liquid, its pH at 6.5 is most critical.

 

[koraks]

Well, if we're nitpicking about pH anyway, then let's address the more significant one: C41 developer is generally around (or exactly) 10.00, not 10.50, AFAIK. Ecn2 is a little higher at 10.25 if memory serves.

 

[Mr Bill]

The original C-41 bleach was based on ferric ammonium EDTA (note the 'E'), with pH in the general range of 6 or 6 1/2 as I recall.

A later bleach was based on ferric ammonium PDTA, and ran at a lower pH, somewhere around 4 1/2 I think. The actual pH values can be found in Kodak's CIS-63 (I think).

When looking at pH values one should be aware that the values may be specific to either a "replenisher" or a "seasoned tank solution." The tank solution is what the film is actually processed in; a replenisher is a solution that can be added to the used tank solution to restore it to its original "strength." In the case of C-41 bleach, the normal commercial process configuration is for film to leave the developer and go directly into bleach. Since the developer has a much higher pH it tends to raise the pH of the bleach. Consequently, the bleach replenisher must have a corresponding lower pH in order to counteract the higher-pH developer that is carried in. Anyway, the point is that one should pay attention to what whether the spec is for tank solution or replenisher. If no such statement is made, a "tank solution" is most likely being assumed.

 

[David Lyga]

Yes, I've read your posts about dilute c41 and to be honest, I've never dared try it. So I certainly cannot argue with your experience. Am I skeptical? Certainly. But I have no facts to back up my skepsis! If it works for you consistently and reliably and has so for years, I couldn't (and wouldn't!) even begin to argue that you're "wrong". The same with your apprach to RA4. It's nothing like mine, but if it works, it works.

Maybe it would be easier 'to dare' trying it if you did as I do: Do tests with only one or two frames and about 20ml of solution.

My stop bath (one shot ONLY as are ALL my processes, including B&W) is highly dilute acetic acid: only 2.5ml of glacial to make a whole liter. This is several times more dilute than 'recommendations' direct. It works, but only one-shot please. - David Lyga

 

[koraks]

Yes, that could be done. The problem, however, is not cutting film strips. The problem is time. Too many things to work on and try out, and not enough time to do all of them. Given the fact that I have already figured out a C41 process that works for me (efficiently, quickly, reliably, with excellent longevity of chemistry), further experimentation in this area is not at the top of my list.

 

[David Lyga]

TIME? I always have chemicals ready to pour and it does not take any excess or wasted time. I have little cups I bought from the Dollar store (I think you have Euro stores?) - David Lyga

 

[koraks]

Yes, TIME. Blessed are those who have an ample supply of it. I, unfortunately, haven't. I can't pursue all the things I find interesting. It's not feasible to do all of the following to the extent that I'd like and sometimes have to: do all of the work that enables me to exist both financially and intellectually, visit all the museums that I'd like to see, explore all printing processes that fascinate me, work out all the ideas for electronic devices that I have bookshelved, create all the images that I want to create, see all the friends I haven't seen for too long, chat up with all the former colleagues/co-workers that I am genuinely interested in to hear how their careers have developed, read all the books that I really should read, go to the market every Saturday to stock up on fresh vegetables and turn those into great food during the week, and most importantly spend this precious precious time with my partner (she deserves a lot more of it than I give her, that's for sure). And if that were only all of it, but alas, I'm afraid there's too much more.

So you may understand that it is not about 'having chemicals ready to pour' (check) or 'having a Euro store' (check, just around the corner). There are many things in life I enjoy. Frankly, figuring out how to make a liter of C41 developer last as long as possible is just not much of a priority in the light of the kind of things I listed above.

And I do enjoy reading what I can about the technical aspects of photography and think along with others who enjoy the same. I left that one out of my little list. Even that interests me more than the number of ft/meters of film per liter I can manage here at home.

 

[Photo Engineer]

The final fix and the wash are the most important in terms of pH. Wash water is not pH 7 though due to the CO2 in the air. The final stabilizer has some effect in compensation by removing some offending chemistry due to being a mild chelating / surfactant solution.

PE

 

[kfed1984]

Some of the film stabilizers, added during coating, are phenolic or HQ like with some of the properties of Vitamin E. That means that they absorb the oxygen that can diffuse into your film or paper during ageing and the oxygen can either oxidize the dyes or the stabilizer. Some of these can be sensitive to Ferricyanide. Thus my caution above.

This is my first explanation of my reluctance to support use of Ferricyanide. The products simply were not tested under those conditions when I was running the tests, so I have no idea. All I can do is put up a warning sign. We won't know for sure for half a lifetime from now probably.

PE

What could be the primary reason that my old color photographs from 1980's are fading while the ones from 1990's on fujifilm paper are just as good as back then? The 1980's prints went soft/yellow, and to my surprise the 1990's are super crisp. Just opened up an old photo album. I'm assuming the fading mechanism in RA-4 paper is similar to that of the film.

 

[kfed1984]

PE's comments are not without great merit. All I can say is that I have used this for years with many different types of C41 films. I have NEVER had trouble. Theory is sometimes trumped by every day experiments. I do have a feeling that this (continued) use of potassium ferricyanide was anticipated by the present manufacturers of C41 film and safety was 'built into' these films. That is how it usually goes with marketplace products. - David Lyga

What is the oldest print you made with potassium ferricyanide? Has it changed/faded since then? What chemical is potassium ferricyanide replacing in the regular chemistry?

 

[kfed1984]

One nice thing about separate bleach and fix for C41 is the better keeping properties. You can stretch the bleach quite far by regenerating it, making the most of the expensive ferric sodium EDTA.

How do you regenerate the bleach, using own chemicals or a commercial replenisher?

 

[MattKing]

What could be the primary reason that my old color photographs from 1980's are fading while the ones from 1990's on fujifilm paper are just as good as back then? The 1980's prints went soft/yellow, and to my surprise the 1990's are super crisp. Just opened up an old photo album. I'm assuming the fading mechanism in RA-4 paper is similar to that of the film.

1980s was the height of low cost minilabs - shortcuts may have been taken.
And of course, they are also ten years older.