Another self-replenishing developer?

[Donald Qualls]

Most of us are probably aware that classical replenishment has limits -- the rule of thumb for, say, D-23 with DK-25R or HC-110 and HC-110R is to discard the tank solution when you've added an equal volume of replenisher. This is not the case, however, with self-replenishing developers (in part because they use higher replenishment rate, as I understand it -- that is, they replace exhaustion by also limit the level of developing byproduct buildup by replacing the entire solution more rapidly than in traditional replenishment).

That said, there are few choices for self-replenishing developers -- Xtol is the best known, and it appears that its clone, Legacy EcoPro, works the same and the new Adox XT-3 can also be self-replenished (though the manufacturer hasn't tested it for that and the user is on their own to find a correct replenishment rate). Champion used to make a self-replenishing developer, but it doesn't appear to be available to consumers any longer, and Ilford's DD (not DD-X) is self-replenishing but only avilable in "makes 25 L" size. And that's is.

Except it may not be. I just learned that the first developer for Fuji-Hunt E-6 lab chemistry is apparently self-replenishing, and first developer for E-6 is essentially a B&W developer -- its job is to develop the halide that would be a negative, so fogging (chemically or with light) and redevlopment with a color developer can form a dye image before bleach and fixer remove all the silver from both developments (and the colloidal silver filter layer).

Key here is that this Fuji-Hunt E-6 First Developer seems to be a self-replenishing solution, and keeps a long time if stored in oxygen-impermeable containers.

So, has anyone tried this for B&W development, and where might one obtain a couple 5L packs of the stuff?

 

[Paul Howell]

Good idea, but I've seen on other threads that Fuji is no longer making E 6 kits, not listed at Freestyle. Would another E6 first developer work as well and all I see are kits.

 

[Auer]

And here I am, clicking on the thread, fully expecting Donald to have a formula for a DIY self replenishing dev....

 

[Donald Qualls]

Good idea, but I've seen on other threads that Fuji is no longer making E 6 kits, not listed at Freestyle. Would another E6 first developer work as well and all I see are kits.

Given the six baths and replenishment capability (in the original thread on the Color section, it seems like that applies to all six baths), I don't think this is kit, I think this is lab chemistry in the same class with the Flexicolor LORR chemicals I buy for my C-41.

 

[Donald Qualls]

And here I am, clicking on the thread, fully expecting Donald to have a formula for a DIY self replenishing dev....

Not today -- I'll need more free time for that level of experimentation.

 

[Raghu Kuvempunagar]

Fuji-Hunt E-6 First Developer seems to be a self-replenishing solution, and keeps a long time if stored in oxygen-impermeable containers.

So, has anyone tried this for B&W development, and where might one obtain a couple 5L packs of the stuff?

You mean for making B&W negatives? Being a reversal first developer, wouldn't it be too active for negative developing if used without dilution? Replenishing the diluted developer might not be as easy as replenishing the stock solution.

 

[Donald Qualls]

@Raghu Kuvempunagar This is part of why I'm asking. Some first developers are more like Dektol stock, and others are less, um, vigorous than that. It might well be that by the time you have the time shortened enough to give a good contrast range, it'll be too short for consistent processing (like HC-110 Dilution A with most camera films). Then again, a lot of us do okay with consistency running 3:15 for C-41, so "under 5 minutes" isn't the bugbear that Kodak's documentation used to make it out to be. Alternatively, it might well be that even at, say, 1+2, the working solution can keep well enough to replenish (you'd obviously dilute your replenisher to the same rate, in this case). I was actually hoping to find someone in this highly experimental crowd who'd done it -- after all, we've got people here to process B&W in coffee, beer, tea, wine, various spices, etc. as well as those who make their own clones of commercial developers for almost every purpose.

Gainer and PhotoEngineer are gone, but there are still a goodly number of folks here who know more about this stuff than I do.

 

[Andrew O'Neill]

I'm a bit confused with the term "self-replenishing". I'm using Xtol-R, but I'm the doing the replenishing by adding back a few mils of stock after each development, not the developer itself...no?

 

[Donald Qualls]

Self-replenishing refers to a system that uses the stock strength developer to start the working solution, and the same stock solution as replenisher. Xtol is the prime example in today's market. In the end, the tank solution will be a little slower working, a little "different" in terms of curve, compared to fresh stock solution, but you don't use a differently formulated replenisher.

I seem to recall the old 777 developer was self-replenishing, but it's been out of production for a long time, and might not work as well with modern films as it did with those available back in the 1950s.

 

[Sirius Glass]

While you are at it, how about self cleaning glass.

 

[Mr Bill]

Most of us are probably aware that classical replenishment has limits -- the rule of thumb for, say, D-23 with DK-25R or HC-110 and HC-110R is to discard the tank solution when you've added an equal volume of replenisher.

I should make a disclaimer that I haven't specifically used those chems in replenished systems. Having said that, I personally don't recognize such limits, nor the need to periodically dump such a system.

There really is no fundamental reason, that I can see, why periodic dumping would be necessary. A proper replenished system should approach an equilibrium condition, and once there, extended use really makes no difference. It seems mainly in the amateur/hobbyist world that the so-called limitations on usage exist. So my best guess is that these recs are to limit the amount of trouble one can get into. It's hard for a replenished process to get into really bad condition if it is dumped every tank-volume of replenisher used. Another possibility is minimize sludge buildup. Commercial machines generally use filtered recirculation systems that pretty much prevent this.

Fwiw I spent a good number of years overseeing the chemical and process control aspects of more than a handful of processes. This included a couple of b&w processes, just not the ones mentioned.

Fwiw, user Laser currently has a book up for sale, the first version of the SPSE Handbook of Photographic Science and Engineering. It has a couple pages on the theory of replenished systems for any who are interested. (Pretty stiff price on the book, though; but I guess it's the going rate now.) But there's no real magic to how such a system works - just a handful of details that are maybe not immediately obvious. (I'll elaborate a little if there's any interest.)

Regarding self-replenished systems, I don't really see them as "proper" replenished systems. Rather they seem to be a somewhat weakened version of the original, operating with a (necessarily) lower concentration of developing agent, along with a higher concentration of development byproducts. So although they can be successful, they are not the same animal as the original. My guess, and it is just a guess, is that the developing agent is just not that sensitive to the byproducts. If it IS strongly restrained by development byproducts then it will be difficult to maintain enough "activity."

Ps, looks like the book sold pretty quick...
https://www.photrio.com/forum/threa...nce-and-engineering-105-w-us-shipping.187414/

 

[Andrew O'Neill]

I see... I guess to me, self-replenishing just means that I replenish it... my self...

 

[Donald Qualls]

There really is no fundamental reason, that I can see, why periodic dumping would be necessary.

The way I've understood it, the issue is that certain development by-products can build up more or less without limit, due to the comparatively low amount of solution discarded or carried over to the next bath from each cycle, and most of these older developers have some level of either inhibition or acceleration due to these by-products (mostly oxidation products of the developing agents, but also wash-out chemicals from the emulsion), leading over time to a changes that may or may not be compensated by adjusting time/temperature or agitation regimen or adjusting replenishment rate. Commercial, high-volume replenishment systems were probably engineered around this condition, and HC-110 may not actually require replacement in such a system with filtering and such (and finer control over replenishment rate than we can usually exercise on 1-4 rolls at a time).

D-23 is an odd case, in that the replenisher contains accelerator that is not present (separate from the already alkaline preservative) in the original stock solution -- but I've used D-23 with DK-25R and found the results consistent within my tolerance, at least (this being a 90 year old system, near enough, I'm sure someone would have noticed by now if it weren't). HC-110 and its replenisher don't, as far as I can tell, materially change the working solution, other than compensating for exhaustion (but that replenisher is no longer available, so it doesn't matter much).

As far as I'm concerned, self-replenishment like what we do with Xtol is the truer sort -- one stock solution, and after initial "seasoning" to bring the tank solution to equilibrium, can without doubt be carried forward indefinitely.

 

[Sirius Glass]

I use my replenished XTOL for years and only dump it when a film test strip does not turn black.

 

[Mr Bill]

I see... I guess to me, self-replenishing just means that I replenish it... my self...

Nah. A "proper" developer replenisher would have a higher concentration of developing agent than the original "tank solution." You see, some of the developing agent is consumed when you develop film; it now has a reduced concentration. So the only way to restore it back to the original concentration, short of replacing the entire tank, is to add an over-concentrated solution, aka replenisher.

If it is a self-replenished developer, like Xtol, where the original developing solution and the replenisher are the same, it is not possible to maintain the original developing agent concentration. So the replenished system will have a different makeup - it is no longer the same.

 

[George Mann]

While you are at it, how about self cleaning glass.

Self cleaning lenses would be nice.

 

[Donald Qualls]

If it is a self-replenished developer, like Xtol, where the original developing solution and the replenisher are the same, it is not possible to maintain the original developing agent concentration. So the replenished system will have a different makeup - it is no longer the same.

Which is why we have the recommendation to "season" a new tank solution of Xtol before expecting a constant condition. After some cycles of development and replenishment, the level of exhaustion and buildup of byproducts will balance against the amount of fresh developer being added. Admittedly, it's something like reusing stock solution, in that you'll need to add a little time to get the same result as fresh stock, but with the correct replenishment rate, you'll get consistent development over an extended (indefinite) period of time -- as long as you can keep getting reliable developer from the manufacturer...

My original post in this thread was partly from excitement thinking there might be another alternative that isn't just another Xtol work-alike. I think I've seen a tentative formula for 777 somewhere (fifteen years ago or more), but we can't depend on Mytol to last unless we have access to the sequestrants Kodak and others use (danged Fenton reaction!). What I'm ultimately after is what one poster hoped for near the top of the thread: a home brewed, self-replenishing developer with maximum film speed, maximum sharpness, and minimum grain (like Xtol); ideally one that doesn't depend on chemicals that are banned for environmental reasons and unavailable to Europeans, such as borax (and we probably won't know what Adox uses in XT-3 in its place for a while).

 

[Mr Bill]

The way I've understood it, the issue is that certain development by-products can build up more or less without limit, due to the comparatively low amount of solution discarded or carried over to the next bath from each cycle..

This seems to be commonly thought, but it's not true.

Fwiw, if you think this through a bit, I think you'll come to the conclusion that neither carryout nor discarding solution can reduce the concentration of byproducts. They are only reduced by adding replenisher. Now, if you don't discard developing solution somehow, then the VOLUME will increase, and this is why you must eventually discard some. But the byproduct concentration will only be reduced by dilution.

Ps, I'm pecking this out on a phone, so can't keep up with you very well.

 

[mshchem]

https://www.uniquephoto.com/fujie61stdeveloperreplenishertm4x10l600005444

 

[juan]

Agfa/Ansco 130.

 

[Donald Qualls]

Wait... From the page linked above: "The Fuji E-6 1st developer or replenisher has a processing time of 6 hours (5 to 7 hours spread)." -- did someone mistake hours for minutes, or is E-6 a LOT slower than I thought? Or is that "processing time" how long it takes them to pick it from their warehouse and ship it (compared to multiple weeks for Flexicolor LORR C-41 Devloper and Replenisher)?

 

[Donald Qualls]

Agfa/Ansco 130.

I don't get it, Juan. For film, you'd dilute that 1+9 (same as Dektol/D-72) and you wouldn't normally attempt to store a solution at that dilution, never mind replenish it. It certainly doesn't seem it would be useful for film in stock strength where self-replenishment might be attempted.

 

[MattKing]

Actua

Fwiw, if you think this through a bit, I think you'll come to the conclusion that neither carryout nor discarding solution can reduce the concentration of byproducts.

Actually not true. And particularly not true if you aren't working with deep tanks.
You just need to discard before you replenish.
And you need a developer like X-Tol that has the capacity to develop a large number of rolls with a small volume of developer, because that ensures that the replenishment process is keyed more to the removal of excess byproducts than it is to the replacement of chemical activity.

 

[Mr Bill]

Which is why we have the recommendation to "season" a new tank solution of Xtol before expecting a constant condition. After some cycles of development and replenishment, the level of exhaustion and buildup of byproducts will balance against the amount of fresh developer being added.

I understand. And this is ALMOST how a proper replenished system should work. The seasoning brings byproducts to the aim concentration. But prior to that it would also be necessary to dilute the developer slightly, to lower the developing agent concentration to what will become the equilibrium concentration. Then it could immediately be brought into a stable condition, with developing agent and byproducts at some nominal equilibrium concentration. But the downside is that it is not the same as single-use Xtol. A different animal, so to speak.

In my view a self-replenished system is really something of an uphill battle. I think a better design goal would be to select some sort of developing solution to start with, and the design should include some concentration of development byproducts. The point of having them in there is so that you could control them via dilution with replenisher. This would determine the required rate for the replenisher. Then it would be a matter of finding what concentration of developing agent is needed, at that replenishment rate, to balance out the avarage amount of developing agent consumed. I'm not saying that this is easy to do, just that this is probably a better-controlled approach. Of course there are other things going on, such as some amount of evaporation as well as developing agent being oxidized by the air. Plus the need to keep preservatives at a steady level, and a controlled pH level.

 

[juan]

I don't get it, Juan. For film, you'd dilute that 1+9 (same as Dektol/D-72) and you wouldn't normally attempt to store a solution at that dilution, never mind replenish it. It certainly doesn't seem it would be useful for film in stock strength where self-replenishment might be attempted.

Yeah. Forgot about that dilution. For paper, I dilute one liter to two liters, use one bottle as developer and the other to replenish.