slowing down HC-110 development

I have been trying to figure out how to slow down HC-110 development. (The reason isn't too important, but we can go into that if anyone cares.) Obviously, one approach is to use a more dilute developer, but this would end up forcing me to develop one roll of film in a four-film tank in my Phototherm, so that doesn't seem like an ideal solution.

Recently the thought occurred to me to reduce the pH of the HC-110 solution. To that end I have done some very preliminary experiments... too preliminary to report really, but I am going to do it anyway.

I prepared several HC-110 solutions. One was basically dilution H (approximately 1 in 64 or so). The others were roughly at dilution A (about 1 part in 16). I added various amounts 5% distilled white vinegar to the dilution A solutions. I used various amounts of vinegar, ranging from 1/4 of the amount of HC-110 (by volume) to 4X the amount of HC-110. I tested the speed of development by putting in some pieces of fully exposed film in each solution, and visually compared how fast they developed.

To summarize the results in a nutshell, it looks like the when I used 1.5X of vinegar the development proceeded noticeably faster than in dilution H, and when I used 2X of vinegar relative to HC-110 the development pretty close to as fast (but probably slightly slower) than in dilution H. (By the way, when the vinegar volume was 4x of the HC-110 volume there was no noticeable development at all.) Based on these very preliminary results it looks like using 1.75x or maybe 2X volume of vinegar relative to the volume of HC-110 (at concentrations similar to dilution A) will probably give about the same development speed as dilution H. This is basically finding a likely range around which further (more complete and more rigorous) testing can proceed.

Once this is dialed in, I'm not sure what it will do to the quality of the results. I suspect that at the concentrations of dilution A the solvent action will be pretty strong, especially given the more extended development time implied by the lower pH, so it might result in fine and/or mushy grain, and who knows what it will do to effective film speed and sharpness, but I'm not expecting impressive results for film speed.

Also, it is likely that the added acid will probably push the buffer to somewhere near the edge of the buffering capacity of the developer, so accuracy of measurement of the mix may end up being quite important in order to get a reproducible pH.

This is all very preliminary, and I expect it may be weeks before I get around to completing a more rigorous series of tests, but I thought I would post this in case anyone is interested.

If successful this project could lead to a recipe that will allow me to process four rolls of film using HC-110 in my Phototherm. This would be nice because it would be more convenient than using powder developers and less expensive (and finer grained) than using something like liquid T-MAX developer and hopefully finer grained than using Rodinal.

alanrockwood said:

Also, it is likely that the added acid will probably push the buffer to somewhere near the edge of the buffering capacity of the developer, so accuracy of measurement of the mix may end up being quite important in order to get a reproducible pH.

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Exactly the comment I intended to make when I reached the vinegar part. Plus, your developer would not have much in common with "HC-110" as it was carefully designed and optimized. Have you investigated temperature? According to the Ilford dev datasheet at 13°C dev time is doubled. But then again, that is outside the range for which the developer was designed and tested. And the generic Ilford temp compensation curves are only a first approximation for a specific developer. Only your test can tell.

You may end up with a multitude of problems regarding contrast, speed, fog, grain and sharpness. All of these are optimized for the "original" concentration ranges for the developer.

PE

I'm guessing that you are trying to maintain the Phototherm's standard temperature - otherwise you would be best served using a lower temperature.
You might be able to achieve what you want with partially exhausted developer, but I don't know that you could create and control that process reliably.
How about replacing the water rinse with a second batch of HC-110 "H"?

I think dilution is the safest route really. As you pointed out, by dropping the pH, you go outside the buffering envelope of triethanolamine. If you drop the temperature too far, you get to the point where the hydroquinone drops in activity precipitously.

To elaborate a bit, one of the issues I am trying to solve with these experiments is that I want to develop fomapan 100 in my phototherm. There are a number of reasons why it might not be a good idea to try to develop fomapan 100 in HC-110, starting with the fact that to dilute it enough to get a reasonable development time I would need to go to dilution H (1+63), or at least dilution E (1+47). Considering that there is a 6ml minimum specification of HC-110 concentrate per roll and the fact that the largest tank I have for my phototherm is 420ml, I could only develop one roll at a time, even though the tank can hold four rolls.

I could use a higher amount of concentrate to do more rolls, but the developer would then be at a dilution rate that would develop the film too fast to get reliably reproducible development.

Dropping the temperature to slow things down is not practical because the Phototherm is programmed to process at a temperature 75 F for B&W processing. To process at a lower temperature would require having a new chip burned ($100, assuming it is still possible to have that done), and even then there are limits because it won't go below ambient temperature. (It adjusts the temperature by heating. There is no option for cooling.)

TMAX developer will work, and has the advantage that it gives higher film speed, but it is comparatively expensive and produces grainier negatives.

Rodinal might work, and the cost is favorable, but I suspect it might run into some of the same problems with dilution rates for developing Fomapan 100 that plague HC-110 developer. Plus there are the issues of graininess and lower film speed.

I agree that the scheme I am investigating might un-balance the highly optimized HC-110 formula, but the problem with HC-110 is that it is not optimized for my application, so I would like to tweak it a bit to dial it in to my requirements. It remains to be seen if lowering the pH will put HC-110 so far out of whack as to produce bad results.

As far as graininess is concerned, it is my understanding that all else being equal, lower pH tends to favor finer grain. Also the fact that the sulfite concentration will be much higher than HC-110 dilution H will probably favor fine grain. My wild guess is that HC-110 adjusted to lower pH is likely to give finer grain (probably of the mushy variety) and lower effective film speed.

I am also thinking about adjusting the pH using ascorbic acid, the acid form, not the ascorbate form. There would be competing effects working at somewhat cross purposes with each other. It would lower the pH, which would slow down development, but it would also add a superadditive developer, which would speed up development. My guess is that adding a little ascorbic acid would speed up development due to the superadditive effect, but adding more would slow down development through the pH effect.

Replacing the wash step with a second batch of dilute HC-110 is an interesting possibility. It would produce a little bit of carryover of developer into the fixing solution.

alanrockwood said:

Considering that there is a 6ml minimum specification of HC-110 concentrate per roll

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It's strange, there was a guy, Covington, I think, who had a major webpage on HC110 that when I first encountered it called out 3mL per roll as a minimum. (I downloaded a copy of it for reference.) When I saw some later discussions about 6 mL, I went back and looked and found it was changed. I have typically done single rolls of 35 mm at something like 3.7 mL per roll without noticing unhappiness. Makes me wonder if there's some butt covering involved. I have definitely not done a major scientifically precise test of that capacity, but I suspect it's to cover a worst case situation. So unless you're photographic sparse line drawings on a white background, maybe the 6 mL isn't worth losing sleep over.
Disclaimer: Your Mileage May Vary!

DWThomas said:

It's strange, there was a guy, Covington, I think, who had a major webpage on HC110 that when I first encountered it called out 3mL per roll as a minimum. (I downloaded a copy of it for reference.) When I saw some later discussions about 6 mL, I went back and looked and found it was changed. I have typically done single rolls of 35 mm at something like 3.7 mL per roll without noticing unhappiness. Makes me wonder if there's some butt covering involved. I have definitely not done a major scientifically precise test of that capacity, but I suspect it's to cover a worst case situation. So unless you're photographic sparse line drawings on a white background, maybe the 6 mL isn't worth losing sleep over.
Disclaimer: Your Mileage May Vary!

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Yes, the chances are there is a bit of a safety factor built into the 6ml minimum.

I think that the 6 ml figure takes out the possibility of there being unsatisfactory results with something like a high key subject (scenes of sand or snow).
How about 1+1 X-tol?

MattKing said:

I think that the 6 ml figure takes out the possibility of there being unsatisfactory results with something like a high key subject (scenes of sand or snow).
How about 1+1 X-tol?

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I would like to try X-tol. I even have an unused package of it. However, I like the convenience of liquid developers.

Maybe pyrocat is an option. Development time for foma100 is around 7 minutes at 1+1+100, I always develop 135/36 rolls in 150ml so 420ml should be enough for 2 films and you may even get away with 3. Liquid concentrates and keeps very well if you have the glycol version.

What about using HC-110 as part A of a 2 bath developer?

Since hc110 is a single concentrate with both the developing agents and the activator in the same comcentrate, it can never be a proper two bath system.

Just checked typical pH value (9.1) of HC-110 and compared it to pKa value of Triethanolamine (7.74). You should be well within range of good buffering with your experiments.

One thing which may taint your results is the extra dilution you run into as you add more and more vinegar to HC-110 dilution A. Therefore you have been comparing developers which differ in more than just one property. In fact your 1+4 developer was more dilute than HC-110 dilution H! Therefore I'd recommend you get a different compound for lowering pH (e.g. boric acid, more concentrated white vinegar, pH down from pool supplies, ...) and always maintain HC-110 at dilution A to get a meaningful comparison.

Perhaps sodium metabisulfite would be a good choice as well.

Two way that work well in my darkroom to slow down development.

1) Lower development temp. I was able to get my Jobo down to 18C with crushed ice in the un-used bottles. I did have to keep replacing the crushed ice in the un-used bottles, as 18C is much warmer than 4C icewater.

2) Dilute the developer out into spare bottles. I was able to do 100:1 Rodinal that way using six bottles; dumping and re-filling with fresh developer five times during the development cycle.

Alan,

I haven't read the whole thread, but Bob Carnie's technique springs to mind. Use a higher dilution to give you a longer development time. To deal with the exhaustion due to insufficient capacity, change to fresh developer (at the same dilution) halfway through the development. You'll have to test for times, of course, but it's been my experience that halving the dilution (e.g., from 1+31 to 1+63) doubles the development times with HC-110. You could use this as a starting point.

Hope this helps,

Doremus

Rudeofus said:

... pKa value of Triethanolamine (7.74)... One thing which may taint your results is the extra dilution you run into as you add more and more vinegar to HC-110 dilution A. ... Therefore I'd recommend you get a different compound for lowering pH (e.g. boric acid, more concentrated white vinegar, pH down from pool supplies, ...) and always maintain HC-110 at dilution A to get a meaningful comparison.

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Thanks for the info on pKa of triethanolamine.

Good point about the dilution ratio. Another way to maintain the same dilution would be to keep the water + vinegar volume constant. For example, 26 mL of HC-110 and 393 mL of water would result in the same dilution of HC-110 as would 26mL of HC-110 plus 52 mL of vinegar and 342 mL of Water. For the initial test with clips of film I didn't worry about that because the extra dilution factor is only moderate, but for detailed studies the dilution should be held more rigorously constant.

To make things simple, read this post published by J Brunner a few years ago. It results in reasonable developing times and excellent result ( unless the images are crap already at exposure ).

Karl-Gustaf

https://www.photrio.com/forum/resources/hc110-made-simple.220/

I did a little more work. I used 1 part HC-110 and 15 parts of 0.625% acetic acid. (The acetic acid solution was made by diluting 5% distilled white vinegar into water.) I am posting the characteristic curve I got. The development conditions are listed on the figure.

A couple of observations: HC-110 is often said to produce an upswept curve. However, in this case the curve is distinctly S-shaped. I would describe the curve as having fairly long toes and shoulders. What do you think? The fact that I tortured the HC-110 rather severely by diluting it into 0.625% acetic acid is probably responsible for the change in character of this developer. I might have overdeveloped the film slightly because G-bar is about 0.65. Cutting the development time a bit should bring the slope down... or maybe I will just leave it as is.

The effective film speed worked out to be an e.i. of about 50, which is about half of the nominal film speed for Fomapan 100, but pretty much everyone says that rating Fomapan 100 at an e.i. of 100 is wildly optimistic, plus these film samples are years out of date, so this result is probably not much of a surprise.

I haven't tried evaluating other factors, such as grain or sharpness.

Any thoughts?

It's kind of hard to comment on developer characteristics if you use such old film ...

Also, it would be helpful if you also post a graph made with straight HC-110 1:16. This way you'd also have a proper reference regarding film toe shape and location.

[QUOTE="Rudeofus, post: 2164294, member: 34922"...Also, it would be helpful if you also post a graph made with straight HC-110 1:16. This way you'd also have a proper reference regarding film toe shape and location.[/QUOTE]

Fomapan developed in 1:16 HC-110 would turn out black because that dilution is too active for this film. That's why I reduced the activity by adding acid, and 1:16 was required in order to get the recommended minimum 6 mL of developer per roll of film, given the volume of the tank in my processor.

A curve of Fomapan developed normally for it then would be of use. This curve does not tell me much.

PE

Although I did not try this with HC-110, I have always used baking soda to slow development. It is not drastic like vinegar and seems to allow for great tonality. You will have to experiment, but I would try about 5ml in your 300ml working solution. Try a clip test first: Why waste a full roll?


CORRECTION THE DAY AFTER: use only ONE mL of baking soda to experiment with, as the stuff is quite powerful. After trying that, use either less or more if needed. Do clip tests. - David Lyga

David, baking soda is a solid. So, what is 5 ml???

PE