Starting a Minimum ECN-2 DIY Developer kit.

Hi! after a year's adventure using the notorius Cinestill Cs2 ECN-2 kit with DIY Remjet Remover, I decide to start from scratch to build my own ECN-2 kit.
By following https://www.kodak.com/content/produ...ssing-KODAK-Motion-Picture-Films-Module-7.pdf, I have the following items ready:

I removed the need of Kodak Anti-Calcium, because the developer is planned to be one- or few-shot. I know it is https://www.scbt.com/p/sodium-3-nitrobenzenesulfonate-127-68-4 , but it feels hard to buy those as a mere civilian.
I will directly use a neutral B/W rapid fixer and won't bother dealing with DIY fixers or creating from the remaining BLIX constituents.

However I'm a little bit unsure about the longevity of the said bleach to be used.
By following https://www.photrio.com/forum/resources/converting-c-41-e-6-blix-into-separate-bleach-and-fixer.74/, I identified that the Bf6 Part B is Ferric Ammonium EDTA, so by adding Bromides and adjusting to pH 5.5 it will become a usable bleach.
It's promised to be active for a dozen rolls mimimum, and can be used for more rolls if I add extra Bromium to the solution.
However, is the bleach able to be replenished by simply adding some Sodium Bromide, and expose the bleach to open air to oxidize the Ferrous ions to Ferric?
For example, my plan is, each time when I use the bleach, I'll add 5 grams of Sodium Bromide, then give a good shake/air exposure to the solution, finally adjusting to pH 5.5 by adding some white vinegar.
Will the FeNH4EDTA be stable for a long time (for example, a year) so that I don't need to buy another pack of Bf6 to replenish?

Thanks!

Welcome to Photrio!

I think your approach will work.

hamoodhabibi said:

each time when I use the bleach, I'll add 5 grams of Sodium Bromide, then give a good shake/air exposure to the solution, finally adjusting to pH 5.5 by adding some white vinegar.

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Sounds good and I think in fact you need a lot less than 5g NaBr. I suspect that ca. 1g would suffice. You could try to work it out based on an assumed silver load of around 5-10g/m2; keep in mind that the bleach only has to work on the developed silver image, so the amount of silver it actually has to convert is a small part of the total silver load. My gut feeling says that a few hundred mg's of bromide may be consumed.

AFAIK the Ferric Ammonium EDTA should be stable in solution. If you adjust pH from time to time and add some bromide now and then, I would expect your bleach to work indefinitely. It'll be slower than a regular C41 bleach, which is what I use. C41 bleach is more expensive per liter, but a little goes a long way and it's very very robust. I never bothered trying to DIY an EDTA/PDTA bleach.

You could of course use the cheap and effective ferricyanide bleach with your ECN2 film; this is also a no-fuss, stable solution that keeps indefinitely as long as you replenish it once in a blue moon.

As to the fixer, ideally you would adjust its pH to about 6.5 for use in a color process. However, with sufficient washing of the film after fixing, I never observed any ill effect of using an acidic fixer. However, my standard fixer is (again) a C41 fixer because it's no-fuss, keeps well (concentrate), is fast, correct pH right out of the bottle etc.

Wow, that's tempting. The only chemical on the developer part of that list that I don't have already on hand is CD-3, which isn't hard to source (I'd assuming that potassium bromide can substitute for sodium bromide mole for mole). I keep C-41 bleach and fixer on hand anyway, and sodium carbonate and bicarbonate (the latter in the kitchen, but it's super cheap to get a box and dump it into an airtight jar for the darkroom and sodium hydroxide are there for other developers, so the remjet removing is covered. A 400 foot roll of fresh Vision3 is a lot cheaper per frame than single cassettes of even Gold 200... -- and isn't there also a positive process, ECP-2, for the same films? Or is that for the positive print films that actually get projected?

Donald Qualls said:

(I'd assuming that potassium bromide can substitute for sodium bromide mole for mole)

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Yes, works fine. I always do it that way.

Donald Qualls said:

isn't there also a positive process, ECP-2, for the same films? Or is that for the positive print films that actually get projected?

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I think the latter, yeah. Never played with it, but I routinely do ECN2 development at home and shoot a lot of Vision3 250D these days. Works great.

I skip the prebath for remjet removal and instead remove it at the end of processing. I make a lukewarm, weak solution of sodium carbonate (two teaspoons to half a gallon or so), then pour some of that into the development tank. Shake it like a madman, then dump. Repeat once or twice. Then take the reel with film on out of the tank and put it in a tub with the remaining carbonate solution. While removing the film from the reel a couple of frames at a time, I brush off the remaining traces of remjet with a soft pig hair brush. Then inspect the emulsion side one more time to see if no remjet has found its way onto it; it's usually pretty easy to see, and some rubbing between thumb and forefinger gets rid of it (Vision3 film is really robust). Then wash thorough and finish as you normally do with your color film.

We all have our own ways of doing things; the above is what works best for me in terms of effectiveness, low failure rate, convenience etc. YMMV.

Vision3 is great stuff and unless Alaris will start applying a more sensible price policy to Kodak still films, I'm about to use as much of it as I can.

I find it a bit odd that ECN-2 developer, used for commercial film production since, what, the 1980s? is so much simpler to get right than C-41. On one hand, I'm sure it's intentional since most studios used to process their own film and would want to save all the money they could by buying raw chemicals that ship dry vs. buying liquid concentrates -- but on the other hand, if they can make a color film that behaves that well in a nothing-special developer, why wasn't C-41 made the same way? Just because it was aimed at rapid access and needed to develop at 100F in 3:15?

The development of CD-4 and C-41, I believe, is intended for stable automated operation under large batch sizes, a shorter development time, at a more friendly temperature. However using the ECN-2 process to process films intended for C-41 actually renders acceptable results (but given that CD-4 is more active than CD-3, you have to use 1.3x the original development time when using CD-3 to process C-41 film (p.s. that's why Cinestill packs 5219 500T at ISO 800 and 5207 250D at ISO 400 lol))

In the meantime, after some investigation, I can say that the main difference of C-41 and ECN-2 is the developer (CD-4 vs CD-3). Everything else is more or less similar, could be just differences in amounts each chemical is added. Tetenal/Arista(Cinestill) acutally share the blix in their C-41 and ECN-2 kits.

For a DIY color positive kit, there is an open source formula for E-4, and the openly available Kodak E-6 patent as the basis. This forum actually have guides on how to make a DIY kit following the E-6 patent. However, several caveats exist:
1. both E-4 and E-6 have some additives not easily sourced in public (Hydroquionine is even one of the easier chemicals to get);
2. The fogging agent is also not easy to find. If we decide not to use chemical fogging agents, like what we have in E-4, then after the first developer we will want to expose the films in the air to fog the film.
3. Alternatives to the first developer exist, but their effects are questioned. This is important because color slides are intended to be viewed through projector lights to the naked eye. I haven't found good ways to scan slides while preserving their color.

Donald Qualls said:

I find it a bit odd that ECN-2 developer, used for commercial film production since, what, the 1980s? is so much simpler to get right than C-41

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Well, it's really not all that different. pH is different, so the buffer system differs between the two; the difference in activity of cd3 and cd4 comes into play as well as emulsion design.target gamma etc . C41 takes a tiny little amount of iodide; maybe for finetuning of color balance at the extreme of the curves. C41 includes HAS which mostly seems a measure taken to have a stable developer that will survive some exposure to air in a replenished system. I suppose ECN2 is intended to be used with a much higher replenishment rate and a much larger processing volume, so it doesn't get the chance to die.
IDK, this would be my guess as to the differences.

About the bleach - someone had mentioned that you need ammonium bromide, even though the EDTA is ammonium ferric. I haven't tested it, but I plan to for the E-6. Omission of Anti-Calcium will require pH adjustment. It is good to have a stop bath - officially in the process it is quite aggressive, probably there is a reason. Acetic acid will work, for many people sulfuric acid is not an option.
The fix can be used acidic for black and white, but you need to raise its pH to near neutral.
For the exotic chemicals at e4/e6 - forget about the e4 reversal chemical - it's terrible stuff. But the reversal chemical from e6 can be used - it is cheap and easily available. The biggest pain is hydroquinone monosulfate.

Thank you for the shout! I have a CD-3 manufactured Sep 24th , it's fresh!
Have you tried a real world Blix vs separate Bleach vs. Fix test for the ECN-2 process yet? I've hadn't had time to , but it's definitely on my list. I am mainly looking for sharpness and grain size , if any difference there. Then wait a few weeks, and try again to see if the Blix goes south quicker.

For E-6 , try HC-110 , expose to light, then process the rest in ECN-2 chemicals. A user named "B_Huij" had delightful examples and a formula on another forum, I just couldn't find the link at this moment. That's another thing I'm trying very soon - I'll post my results if they are worth sharing.

That may be @BHuij on this forum.

koltin said:

Thank you for the shout! I have a CD-3 manufactured Sep 24th , it's fresh!
Have you tried a real world Blix vs separate Bleach vs. Fix test for the ECN-2 process yet? I've hadn't had time to , but it's definitely on my list. I am mainly looking for sharpness and grain size , if any difference there. Then wait a few weeks, and try again to see if the Blix goes south quicker.

For E-6 , try HC-110 , expose to light, then process the rest in ECN-2 chemicals. A user named "B_Huij" had delightful examples and a formula on another forum, I just couldn't find the link at this moment. That's another thing I'm trying very soon - I'll post my results if they are worth sharing.

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LOL I literally just bought from you yesterday to kick the last bit off in my plan. My original plan was to buy 3kg of CD-3 from Alibaba for like $500 and distribute if anyone wants them, but second thought told me not to be in that of a hurry.

I have to say that using a blix isn't the sharpest way to do.
Also blix has the risk of being depleted without notice. My original idea was to use Cs2 blix at 2:1 to the developer, but after the 25th roll out of a blix, the film wasn't completely bleached, came with remaining silver on the film, and screwed the scanner.

MattKing said:

That may be @BHuij on this forum.

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That's correct!

koltin said:

A user named "B_Huij" had delightful examples and a formula on another forum

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Here, too: https://www.photrio.com/forum/threa...nti-calcium-4-replacement.203626/post-2763771
The post linked to is the 'final report' and the preceding process is also documented in the thread it's part of.

lamerko said:

someone had mentioned that you need ammonium bromide, even though the EDTA is ammonium ferric.

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Excess of sodium or potassium will slow the bleach down dramatically. @Rudeofus may be able to comment on this.
I don't know at what point this will become problematic. It is a concern that I overlooked in my earlier post especially when replenishing the bleach with bromide. Thanks for highlighting it.

hamoodhabibi said:

I have to say that using a blix isn't the sharpest way to do.

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Blix has often argued to be problematic w.r.t. retained silver, which allegedly is why it was never used for large-scale E6 processing in pro labs. Yet, others argue that it works fine for them. I guess YMMV. One way or another, blix is a precarious balance and would be challenging to keep alive in a replenished system. I'd be inclined to use an RA4 paper blix if there was a pressing reason to use a blix in the first place. RA4 blix would stand up to replenishment - but the blix time would have to be extended far beyond normal E6 process parameters.

hamoodhabibi said:

LOL I literally just bought from you yesterday to kick the last bit off in my plan.

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Woah nice ! Thank you for the order- it's in the mail! Be sure to check the surfaces for any vapor after mixing or chemicals after weighing, if you wet a towel and it turns purple then it's on the surface still.

hamoodhabibi said:

I have to say that using a blix isn't the sharpest way to do.

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I haven't used blix in years , I've only seen comparisons online and seen blix enlarges the grain. In my own experienec , I vaguely remember being uninspired using the home developing kits because it could look cloudy/hazy, grey skies - I'm guessing that what retained silver looks like @koraks ? In my darkroom college class we use Blix in the color print machines , so it got into my head again. Thus looking up the formulas. I process many rolls of Vision3 weekly for labs, and have always used the public Kodak formula with separate bleach and fix, and have always had wonderful results. I either add time , or use the replenisher. I also use scientific filters to get the silver out of the fix / remjet out of the developer and bleach, and dust out of the prebath. Lots of results using this method on my site!
I thought to use this . I just have no idea what time / temperature. A lot of the formulas I come across lack those details. If you're already making C-27/C29 , and making your own stop bath / fixer , then all you need is the EDTA.

koraks said:

Here, too: https://www.photrio.com/forum/threa...nti-calcium-4-replacement.203626/post-2763771
The post linked to is the 'final report' and the preceding process is also documented in the thread it's part of.

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I appreciate the help there ! Here's the original post I was thinking of. The E-6 is one I really want to get down , I grabbed a 400' Ektachrome before the.. events , and - I already have HC110, so if I can integrate it into my ECN-2 workflow , I'll be using it a lot more.

koltin said:

Here's the original post I was thinking of.

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Well, technically speaking, the original was the one I linked to, as it precedes the Reddit announcement by several months! However, it's not important and I'd also like to note that @BHuij has been doing great work overall to bring together people from the photographic community across different platforms in his print exchange https://www.photrio.com/forum/threads/fall-2024-print-exchange-via-reddit.208873/

koltin said:

I'm guessing that what retained silver looks like @koraks ?

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Yeah, this all matches retained silver. More grain, more contrast, reduced saturation, some color shifts towards brown/yellow (due to the small silver grain size that remains) especially visible in light-colored areas, etc.

koltin said:

Blix in the color print machines

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For paper it's easier since the silver load is waaaaaay lower than in E6. It's also mostly silver chloride with a little silver bromide, and no silver iodide. The makeup is different in E6 film and I suspect this greatly affects blix speed.

@hamoodhabibi - It's clear that your chemistry knowledge vastly outstrips mine. I have a very layman's understanding of how this all works, but bullishly pressed forward in my experimentation all the same, and evidently lucked into pretty good results with E-6 films and ECN-2 chemistry (well, and HC-110). I am putting far less effort into balancing pH or replenishing bleaches or anything like that. I just make up my developer from powder immediately before heating it up for use, and keep careful track of exhaustion on my stop bath/bleach/fixer (which are all more or less simplified versions of the published ECN-2 chemistry). So far excellent results from Vision3 films (250D is my favorite), great results from C-41 films (using a 5 minute dev time instead of 3), and very good results with Ektachrome. I think my recipes and E6(-) process were outlined pretty specifically in the Reddit thread linked, since a lot of people there asked. Best of luck and please do share your results! I will happily offer to answer any questions or help in any way that I can, but truthfully I doubt I know anything about this that you don't already know

@MattKing - Yep, same BHuij here and on Reddit

@koraks - Thanks for the shoutout and for plugging my print exchange - Something in this thread caught my attention; you mentioned that retained silver (often an unintended effect of using blix instead of separate bleach/fix) can cause a brown or yellow cast in the highlights. In some of my earlier experiments with devloping Ektachrome in HC-110 and ECN-2 soup, I had one frame with a rather noticeable yellow cast to the highlights. IIRC, you pointed it out and I hand-waved it away citing 81A filter, low-CRI light source with blue cast, and AWB on my iPhone emphasizing it. All of which might have been factors, but now I wonder if I actually under-fixed this frame. I've never gotten to the bottom of what caused the yellowish-ness on the corner of that sheet, and it has kind of bothered me. Though I do always use a separate bleach and fixer, I wonder if my fix times are too short. I have been doing 5 minutes at ~100°F in a rotary system for my Ektachrome sheets and rolls. Possible that's not long enough? I can probably rule out exhausted fixer, as I'm fastidious about tracking its exhaustion, and pretty conservative about which point I toss it and mix up fresh. 500ml of ECN-2 fixer is essentially a negligible cost compared to an $8 sheet of Ektachrome 4x5

And, if you think underfixing might actually explain my yellow cast on that frame, is this something where I could just toss it back in a tray of fixer for a few minutes, then re-wash and re-stabilize in formalin?

BHuij said:

And, if you think underfixing might actually explain my yellow cast on that frame, is this something where I could just toss it back in a tray of fixer for a few minutes, then re-wash and re-stabilize in formalin?

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Yes and yes!

I'll give that a shot. Next time I run any color I'll sneak that sheet back into the fixer, wash, and stabilizer and see if it improves things.

Maybe it's worth an extra post about how I discovered that the film is underbleached and has silver retention; but in one sentence, because some scanners conduct ICE probably by scanning in infrared, the existence of silver will screw the scanner and trick the algorithm.
You don't need to feel my frustration when I found my scans coming from Fuji Frontier SP3000 blurred and marred with strange patterns

hamoodhabibi said:

because some scanners conduct ICE probably by scanning in infrared, the existence of silver will screw the scanner and trick the algorithm.

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Yes, this makes good sense. I imagine you got a lot of weird, smeared-out details in those scans.

Early update on the test: Results are magnificent. Colors are nice, and the separation of blix may have improved resolution.
Future tests I think will be more about the longevity of such formulae, e.g. how long can the bleach sustain, whether adding hydrogen peroxide helps restoring ferrous ions, and the capacity of the fixer and developer (I plan on 8 rolls per 1L of developer).

Yeah, that appears to be looking good!

@offtopic

What camera/databack did you use to print info between frames?

lamerko said:

@offtopic

What camera/databack did you use to print info between frames?

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That's a Contax G2 with its data back.

hamoodhabibi said:

That's a Contax G2 with its data back.

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Thanks!

They look great!