Have D-76 and ID-11 given different contrast to you?

cliveh · Nov 2, 2022

DREW WILEY said:
I don't know if anyone mentioned it yet; but you either need to standardize on 76 freshly mixed, or after it's had time to reach pH equilibrium about a week later. And the results will differ. Special buffered versions of 76 also exist, to alleviate that issue. So we're really talking about a category of developers with specific minor but pertinent differences, even in terms of starting usage. This kind of problem has been known for a long long time. When in doubt, test first.

If the developer is kept air tight, why would the pH change over time? Surely whatever it is mixed with, acid or alkali will determine the pH almost immediately?

Lachlan Young · Nov 2, 2022

Juan Valdenebro said:
We're talking about times by Ilford only.

Tri-X and HP5+ run very very close to each other in ID-11/ D-76 in terms of temp/ CI - not a big surprise if you understand the aims/ intentions/ history of HP5. Ilford's published times for D-76 and HP5+ essentially tally with Kodak time/ density/ EI aim rather than Ilford time/ density EI aim. It's likely they are a carry-over from earlier data (quite possibly for getting HP5/ HP5+ into the US market - the UK market was much more aware that D-76/ ID-11 were interchangeable) sheets. So there's no there there, other than that you sometimes need to be slightly wary about the aim CI/ G-bar given by Ilford for their films in non-Ilford chemistry (but not for non-Ilford films in Ilford chemistry).

DREW WILEY said:
I don't know if anyone mentioned it yet; but you either need to standardize on 76 freshly mixed, or after it's had time to reach pH equilibrium about a week later.

Hours, not days.

cliveh · Nov 2, 2022

Lachlan Young said:
Tri-X and HP5+ run very very close to each other in ID-11/ D-76 in terms of temp/ CI - not a big surprise if you understand the aims/ intentions/ history of HP5. Ilford's published times for D-76 and HP5+ essentially tally with Kodak time/ density/ EI aim rather than Ilford time/ density EI aim. It's likely they are a carry-over from earlier data (quite possibly for getting HP5/ HP5+ into the US market - the UK market was much more aware that D-76/ ID-11 were interchangeable) sheets. So there's no there there, other than that you sometimes need to be slightly wary about the aim CI/ G-bar given by Ilford for their films in non-Ilford chemistry (but not for non-Ilford films in Ilford chemistry).

Hours, not days.

No, seconds.

DREW WILEY · Nov 2, 2022

It's a well known factor, otherwise, buffered versions like Formulary offer wouldn't even exist. Rounding it out to a full week might be just for sake of a margin of error; but mere hours it sure ain't! Take your chances, and when in doubt do actual densitomer full-curve plots. Have you done that yet? I doubt it.

As for Tri-X and HP5, you need to be more specific. Tri-X currently exists in two distinct versions.

Lachlan Young · Nov 2, 2022

cliveh said:
No, seconds.

It does take a bit of time for the HQMS to form (because that's what's happening) - but there will be differences across whether you're mixing 1L, 5L or 50L. And there is going to be some difference between research lab and manufactured product in practical use. Nevertheless, most of the 'problems' come from the overwrought and ultra-low throughput types.

Lachlan Young · Nov 2, 2022

DREW WILEY said:
when in doubt do actual densitomer full-curve plots

Don't assume that others haven't, OK? Believe you me, it'd be immediately visually noticeable, never mind sensitometrically detectable. The buffering issue is something different and relates to replenishment capacity/ ability to autoreplenish (hence Xtol, Ilfotech DD etc) - not anything to do with single-shot use.

DREW WILEY · Nov 2, 2022

Replenishment is a different set of variables, though somewhat parallel. And the end result is noticeable. I used 76 for technical lab applications where densitometer set standards were required, as well as specific curve shapes. The distinction between fresh mixed and stabilized later solution was crucial; and everything I did was one-shot. Perhaps the distinction is not so evident in casual use of medium toe films like HP5+ and TriX Whatever; but it's still there, and might cause more serious problems with more linear films.

A general user would be advised to read the information on Formulary's TD16 Improved D76; and they can judge for themselves whether those who formulated that were wrong when accusing regular D76 of pH rise. The full tech sheet spells out more with respect to the replenishment issues, especially when traditiona; 76 is too aggressively mixed, perhaps symptomatic of power mixing which was once commercially common. And TD16 wasn't the only reformulation addressed to this particular issue. But I personally moved on from all fashions of D76 long ago, including that one.

pentaxuser · Nov 3, 2022

I had a look at the instructions for both D76 and ID11. The Kodak Alaris instructions were dated December 2017 and called J-78. The Ilford/Harman instructions were dated June 2010. The Harman one gave mixing instructions and said the mixture could be used immediately while Kodak didn't mention anything on mixing nor as far as I could see anything about when it could be used

So unless someone can point me to other Kodak instructions it would seem a not unreasonable conclusion were you to be the man-in-the-street would be that there is no reason to wait with either developer

I wonder why Kodak does not make it clear that a wait of several hours or days is recommended if doing so avoids the problems mentioned?

pentaxuser

MattKing · Nov 3, 2022

The current packaged products has more buffering than earlier versions, which probably makes a difference.
It is also important to remember that D-76 for most of its life was intended for deep tank production lines and replenishment. A change in activity in that environment is considerably more consequential than for those of us who develop a couple of rolls a week.

pentaxuser · Nov 3, 2022

MattKing said:
The current packaged products has more buffering than earlier versions, which probably makes a difference.
It is also important to remember that D-76 for most of its life was intended for deep tank production lines and replenishment. A change in activity in that environment is considerably more consequential than for those of us who develop a couple of rolls a week.

So, Matt, does that mean that nowadays the difference in activity levels between D76 immediately after mixing and say a day later has for all intents and purposes disappeared for the average home processor and thus both D76 and ID11 have now the same or similar enough activity?

Thanks

pentaxuser

DREW WILEY · Nov 3, 2022

Kodak doesn't even make its own chemistry any more; and I'm not qualified to state how many if any minor changes to D76 transpired over the past couple decades. I'm having enough trouble keeping up with HC-110, but do have enough of the older concentrate on hand that it's not going to be particularly worrisome to me anytime soon. And I do know that some kind of subtle change occurred with HP5-plus itself, which they apparently thought was inconsequential, but did in fact alter one particular odd developer tweak I happened to use.

MattKing · Nov 3, 2022

pentaxuser said:
So, Matt, does that mean that nowadays the difference in activity levels between D76 immediately after mixing and say a day later has for all intents and purposes disappeared for the average home processor and thus both D76 and ID11 have now the same or similar enough activity?

Thanks

pentaxuser

I would ask someone who uses both - I only use one of them if I'm working in a group darkroom where D-76 or ID-11 is "on tap", and haven't done that for years.
At their core, D-76 and ID-11 use the same developing agents, and function very similarly. Mixing the two is slightly different, due to the one package vs. two package differences.
Historically, if you were mixing up a large batch for your deep tank line, it was important to mix your D-76 ahead of time, in order to allow its activity to stabilize. As there is no mention of that need on current packaging, that delay may not be necessary any more.
I've never heard of anyone using ID-11 who incorporated that delay, but I'm not sure I knew anyone who used ID-11 in the era when deep tank lines were common - it may have been a geographic thing.
Anyone who uses either developer with small volume, inversion tanks to develop small volumes of film can expect to have to either:
1) accept small variations between the results obtained when switching from one developer to the other; or
2) fine tune their times and procedures to get the contrasts to match.
If you are seeking to do number 2, you probably need calibrated exposures and a densitometer, unless visual matching is enough for your needs.

pentaxuser · Nov 3, 2022

DREW WILEY said:
And I do know that some kind of subtle change occurred with HP5-plus itself, which they apparently thought was inconsequential, but did in fact alter one particular odd developer tweak I happened to use.

Do you know what kind of subtle change occurred with HP5+ and when this was? Presumably Ilford mentioned this change somewhere as you know about it? Can you point me to that change and what was the odd developer tweak that you happen to use?

Thanks

pentaxuser

DREW WILEY · Nov 3, 2022

It was in relation to a special pyro tweak I developed myself, which worked in a certain predictable way before but not at all afterwards. I do vaguely recall an announcement that a minor modification to HP5-plus was being made, but that was allegedly so inconsequential that nobody would notice. And in fact it didn't have any effect on me either except for that one peculiar developing technique. And I only shot HP5 in 8x10 sheet formats, never in roll films; so I can't remark about those. They're coated differently.

pentaxuser · Nov 4, 2022

Thanks Drew for the reply

pentaxuser

Paul Howell · Nov 4, 2022

When in the AF, in the early 70s, although not an instruction for use in the technical order, we mixed 5 gallon size D76, as soon as we to about the 50% mark we mixed a second tank so it would be "aged" by time we needed it. Some bases did use replenished D76 along with other replenished developers, at the bases I was at we did not. I always mixed D76 a few days before I needed it, did the same with ID 11. No good reason other than I did not know how the 2 were different. I do use PF version of D76 as I can get in liter size, a gallon is just too much for my current work flow. My all time fav Borax near D76 clone is Ansco/Gaf 17. I'm too lazy to mix it myself from chemistry. I don't recall if there was any issues with Ph stability, I mixed and used it as soon as it was cool.

cliveh · Nov 5, 2022

I also use as soon as it has cooled.

aparat · Dec 6, 2022

I hope it's okay to resume this thread. I have been working on a personal project, comparing ID-11 and D-76 for a number of films. I am still not done, but I have some preliminary data that I can share. So far, it looks like the two developers are very similar in how they render film speed and contrast, but their ultimate effect depends on the emulsion, to some extent.

The data I am sharing today comes from a test, in which I exposed three samples of Ilford HP5+ and FP4+ in a sensitometer and developed in ID-11 and D-76 for 7 minutes at 20C in a Jobo 1520 tank in 250 ml of the developer, using rotary agitation (aiming the for "normal" CI of around 0.55-0.58). I then averaged the results to produce a single curve for each film, in each developer. I still don't have enough data to make any kind of conclusive statement, but, nevertheless, I think these results are interesting. I am gong to continue working on this, as time allows, and will share the results once they become available.

First, I want to include a few plots that show how the individual trials differ from one another. As you can see, there's reasonable consistency there.

An here are the comparisons of the developers based on the averages from the individual samples. As you can see, FP4+ is virtually identical in both developers (CI of 0.57 and 0.58), while HP5+ does produce a slight difference in contrast (CI of 0.52 and 0.56).

Paul Howell · Dec 6, 2022

I guess the buffers in the Kodak branded D76 has a slight effect on fast film? Would have not guessed that. Too bad you don't have a microscope and old AF test chart to measure resolution and grain size.

aparat · Dec 7, 2022

Paul Howell said:
I guess the buffers in the Kodak branded D76 has a slight effect on fast film? Would have not guessed that. Too bad you don't have a microscope and old AF test chart to measure resolution and grain size.

That's an interesting thought; you may be on to something here. I am also inclined to believe that the different chemical compositions of the two developers, however minor, are likely to be the cause of some of the results I am seeing. I have an early comparison for 400TX in D-76 and ID-11. It looks like D-76 produces more contrast (CI=0.72), but a fraction less speed. The ID-11 curves resemble those in XTOL-R. Having said that, I need more data to confirm this early result.

Have D-76 and ID-11 given different contrast to you?

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Have D-76 and ID-11 given different contrast to you?

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