Progress on XTOL-concentrate

john_s said:

I wonder if that reported effect was due to Dimezone-S or whether it would have occurred with phenidone also.

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Alan and John: That's an interesting question. XTOL does fine, and it uses Dimezone-S. But its pH is 8.20. The pH of DS-10 is 8.00, which those slow films might not have appreciated. Based on your postings, I'll start with slow films when I do roll-tests again. The concentrate I'm experimenting with below has a pH of 8.08:

I’ll call this “212D”. 212 is the mixing-date and the “D” means Dimezone. The amount Dimezone-S will change a little to adjust dev-times to be close to D316. My first test-strip (Tri-X) had higher than expected density. There's always a surprise in this business. The SM/AA ratio is 0.429, the same as Trial-130119, so it’s the same concentrate with less Dimezone; you simply use more of it. The composition of this is similar to D316 and its pH is the same, so the testing and times for D316 should also apply to 212D.

Mark Overton

I think too muuch is being made of the fact that DS-10 is not suitable for slow films. It was optimized for medium and fast speed films and therefore one should not expect the best results with slow films. Like most things in photography there are always tradeoffs to be made.

D-316 1 year keeping test results

I have now completed this 12 month keeping test in which ~20ml D-316 concentrate in a 200ml bottle was exposed to air for ~30 min about once a month (1 year sample).
(1) HP5+ was developed in different quite fresh 2 months old D-316 for 2 x Xtol 1+0 time.
(2) HP5+ was developed in the above mentioned 1 year sample of D-316 for 2 x Xtol 1+0 time.

There is little difference between the negatives from (1) and (2) except there is a slight loss of density in the negs from (2), the 1 year sample.

Considering that this is a rather extreme test using only a small quantity of D-316 in relation to the size of the bottle, which was opened many times, and it is unlikely anyone would repeat these extremes in practice, IMO this is a satisfactory result.I believe Mark is running a keeping test which I hope would more closely represent conditions of practical use,and there may be results to come from this later.

Regarding the chemistry of deterioration of D-316,
Ascorbate oxidation is probably the cause of the slight loss in density.
Ascorbate hydrolysis is in my experience negligible, I once had a 50g/L solution of sodium ascorbate in a full sealed glass bottle that was still active after 5 years.
Phenidone oxidation probably only occurs after all the ascorbate is oxidized.
Phenidone hydrolysis is pretty slow, I once had a full sealed bottle of Mytol that took over 3 years to lose activity.

It can be seen that in the 1 year sample the concentrate has gone orange, I suspect this comes from ascorbate oxidation and will run a test using sodium ascorbate solution with nothing else to see if this can be reproduced.

Alan, thanks again for doing this 1-year test. Frankly, I'm surprised it did that well considering how orange it's become. I guess it's more robust than I thought. Even yellowing was making me concerned, but orange? My current formula is similar to D-316, so your results should apply to it. If a bottle were half-full on average, and opened for only 5 minutes when used, and kept refrigerated or frozen, I'd say it would last a few years.

Also, unlike XTOL which dies clear, the concentrate's colour tells us its state. Clear or yellow is okay. Orange means develop a little longer. Red probably means it's too far gone. Nice to know *before* developing film...

Mark Overton

I've been pondering recent results:

* Concentrate 119P (aka Trial 20130119) (uses Phenidone) gives a hint worse grain with Tri-X than XTOL. With Delta-400, 119P is a hint better than XTOL.

* Concentrate D316 (also uses Phenidone) gives the same or a hint better grain with Tri-X than XTOL. This tells me that the higher level of ascorbate (or lower pH) improves grain with Phenidone.

* Concentrate 119D (same as 119P, but uses Dimezone S) gives slightly better grain with Tri-X than XTOL. That tells me that in this dev, Dimezone S is superior to Phenidone.

* Concentrate 214D (uses Dimezone S) gives significantly better grain with Delta-400 than 119P, and somewhat better than 119D. This tells me that the higher level of ascorbate (or lower pH) also improves grain with Dimezone S, and Dimezone S is already better than Phenidone. Here's a comparison of 214D and 119P with Delta-400:

119P: 214D:

214D is my best developer so far. Its formula is:

The only difference between 214D and 212D that I posted a few days ago is that the Dimezone S in 214D was reduced to .08 g (instead of .09 g). This change makes the ascorbate/Dimezone ratio match XTOL. At this point, I plan try tweaking the amounts of metaborate and/or ascorbic acid to drop pH a little, and see what that does. Then I'll decide on a formula and run a bunch of tests on it. BTW, I found it wasn't necessary to resort to hydroquinone, because all the ascorbic acid still dissolves in this concentrate despite the lower level of metaborate. But I still want to try TEA instead of metaborate -- if the ascorbic acid will dissolve, it'll provide an interesting alternate to metaborate.

Actually, my tests show that the amount of Dimezone S makes little difference. 0.07 and 0.09 gave the same curve and grain as 0.08. I figured this meant the dev is regeneration-limited instead of dev-limited, so I reduced the ascorbic acid while keeping pH the same and surprise: It made no difference in dev-speed. I know sulfite also helps with regeneration, so perhaps it's the limiter? But I'm keeping sulfite at 45 g, which is half of what XTOL has, and doubling dev-time (by reducing pH) to get the same solvent-effect.
Good news: This insensitivity to Dimezone-quantity means that you can be sloppy about measuring Dimezone S. Sub-tenth-gram quantities are difficult to measure accurately without a milligram scale, so it's good to know that you can be 10% off and still be fine.

I was reminded that the supply of Dimezone S for us home-brewers might be unreliable. Alfa Aesar synthesized a batch, which Photographer's Formulary sells, but when that batch runs out, it's anyone's guess if they'll synthesize a new batch. Therefore, I suggest that you buy 100 g of Dimezone S from the Formulary. The price is reasonable, and that will give you a lifetime supply.

Mark Overton

Mark;

The synthesis of all of the Phenidone family of developers is rather straightforward. So, if there is a market, it might still be made. It depends on the size of the market.

As for the attached images, do my eyes deceive me or is the Dimezone S example less sharp? That would explain the apparent lower grain.

PE

Michael R and PE: The patches were not in perfect focus, so sharpness is impossible to gauge. I switched to another lens which eliminated the problem of corner-falloff. But the sharpness of that lens isn't the best. As was pointed out before, contacting is the best way to do this, and I need to build a fixture that will let me contact wedges onto 35mm film.

BTW, these developers have similar chemistry to D316, so I figured sharpness will be similar to D316, so I didn't worry about it. But it would be good to be able to check sharpness anyway...

The fine grain of 214D surprised me. At first, I thought the scanner must have been misfocussed, so I re-scanned the neg -- with identical results.

Mark

albada said:

.......Good news: This insensitivity to Dimezone-quantity means that you can be sloppy about measuring Dimezone S. Sub-tenth-gram quantities are difficult to measure accurately without a milligram scale, so it's good to know that you can be 10% off and still be fine...................

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There was a post some time ago by Sandy King, the inventor of Pyrocat-HD, in which he said something similar. I think I remember him saying that if you went over a certain range you got excessive fog, and if under, weak development. But within a range, there was no difference.

Dimezone-S can also be obtained from www.techcheminc.com. This is where I purchase my developing agents. They sell 100 gms for $25.00.

John:
Good to know that I'm not the only one who has seen that odd insensitivity-to-quantity phenomenon. I was trying to change density by varying amount of Dimezone, and density wasn't changing. That took me by surprise.

Jerry:
That makes it three sources of Dimezone S. I looked at the price-list of TechChemInc: They're competitive. Thanks for mentioning them.

Ron:
I scanned Tri-X strips, shown below. Same result: Grain is finer with 214D than with XTOL. But I included the bottom edge of the wedges so the Mackie lines would show. They're about the same. Also, I looked at edge-markings in loupes, and both XTOL and 214D are neatly outlined with black (Mackie) lines of similar density. So it appears that sharpening is comparable. Below, the 214D scan is on the right. The left scan is XTOL with slightly higher contrast than 214D, and the middle is XTOL with slightly lower contrast than 214D. Grain in 214D is a bit finer than both. To make the comparison fair, all three scans have been digitally adjusted to have equal contrast.

XTOL1: XTOL2: 214D:

Here are the graphs of these three strips:



214D shoulders off later (black line), as usual for these D316-like developers. That should help folks who shoot in contrasty lighting, such as mixed sun and shade.

Mark Overton

Great results Mark.

Thanks.

PE

Alan Johnson was kind enough to mail me the negatives from his D316 longevity tests. He used D316 that was 2 months old and 12 months old. As he said, he was rough on the developer, storing it in a 90%-empty bottle at room-temperature, and opening it for a half-hour each month. So that was a worst-case test, resulting in dark orange concentrate. I measured the neg's on the densitometer, and I calculate that 30% more dev-time was needed. From this, you can estimate how much to increase time for various shades of colouration. Here are the time-increases that I would estimate:


I suspect these numbers are good for 214D and similar, not just D316. Also, I suggest freezing the concentrate in storage: Hopefully it will stay clear for a year, and you'll never need to increase the dev-time.

Mark Overton

As well as that test for oxidation I hope to do a test to find if phenidone/dimezone-s will hydrolze by reaction with the water of crystallization in one of these developers.
To speed up the reaction it is intended to place full sealed bottles of concentrate on top of a hot water tank ~40C.
Hydrolysis of phenidone produces phenylhydrazinopropionic acid: C6H5.N.CH2.CH2.CO.NH +H2O -> C6H5.N(NH2).CH2.CH2.CO.OH
Not a lot of people know that.

Alan Johnson said:

As well as that test for oxidation I hope to do a test to find if phenidone/dimezone-s will hydrolze by reaction with the water of crystallization in one of these developers.
To speed up the reaction it is intended to place full sealed bottles of concentrate on top of a hot water tank ~40C.
Hydrolysis of phenidone produces phenylhydrazinopropionic acid: C6H5.N.CH2.CH2.CO.NH +H2O -> C6H5.N(NH2).CH2.CH2.CO.OH
Not a lot of people know that.

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I want to publicly express my appreciation to Alan for running these tests.

BTW, in my prior posting of time-increases based on colour, I incorrectly assumed a linear drop in activity. As ascorbate is destroyed, activity drops slowly at first, and then faster. So I revised my estimates:


Alan is also concerned about water of crystallization (in the metaborate) hydrolysing the Phenidone. Coincidentally, I recently tried developer 214D modified by replacing the sodium metaborate with TEA. The interesting part was the amount of weight-loss due to evaporation during hot mixing: 214D loses about .30 g in the 1-liter formula. The TEA-version only lost .05 g, and my temperature was a little higher. That tells me that either (1) the metaborate-version loses much more water because more water is present, or (2) TEA prevents PG from evaporating.

If anyone cares to try it, I changed 214D to use 2.8 g of TEA-99% and 11 g of PG. The resulting concentrate is at the same 18 g/litre and yields the same pH of 8.08. But it develops faster. TEA seems to cause faster development than metaborate, even at the same pH. Anyway, 214D is similar to D316, and D316 survived a severe one-year test and did well in my extensive tests, so I'll stay with that formulation. TEA must wait.

Mark Overton

It now seems that I won't be able to run the tests mentioned as there seems to be a chemical reaction occurs within D-316 at 40C.

In an unplanned experiment I left a bottle of D-316 on top of a hot water tank for about 2 weeks. The D-316 temperature varied between ~35~50 C, say 40C average.Upon noticing it was there I opened it,still hot, whereupon it foamed and bubbles came out of the solution.2 days after it had cooled to room temperature I noticed that it had formed tiny suspended crystals in half the bottle, see pic.
IDK if this has something to do with borate-glycol compounds being formed.

Other news- A good source of dimezone-S in the UK ,and maybe Europe, is www.moersch-photochemie.com
I sent them an email asking if they knew where I could get 50 grams,received a quote, paid by paypal, and 2 days later it arrived in the UK.
Because the shipping cost to the UK is less, it's cheaper than buying from Photoformulary or the other supplier (TechChem?) in the US.

Alan Johnson said:

IDK if this has something to do with borate-glycol compounds being formed.

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How would these be gaseous ? Very odd indeed ...

Alan Johnson said:

Other news- A good source of dimezone-S in the UK ,and maybe Europe, is www.moersch-photochemie.com

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If you click on the link "shop" on the top left, then click on "Rohchemie" on the bottom of the left bar, you land on a page which shows where Moersch gets his raw chemistry from: Fototechnik Suvatlar. Does that (there was a url link here which no longer exists) sound familiar?

Yes, thank you, they appear to wish to distribute via Moersch:

http://www.alternativephotography.com/wp/suppliers/chemicals-kits/fototechnik-suvatlar

Alan Johnson said:

Yes, thank you, they appear to wish to distribute via Moersch

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I never had a problem getting stuff from Suvatlar directly. It's not like you could order raw chems from the Moersch shopping portal anyway or that Moersch would provide additional services. Note that the email address listed is for Suvatlar himself, and it's a generic mail provider, not some domain under control of Moersch.

Alan Johnson said:

In an unplanned experiment I left a bottle of D-316 on top of a hot water tank for about 2 weeks. The D-316 temperature varied between ~35~50 C, say 40C average.Upon noticing it was there I opened it,still hot, whereupon it foamed and bubbles came out of the solution.2 days after it had cooled to room temperature I noticed that it had formed tiny suspended crystals in half the bottle, see pic.

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Your picture is identical to the crystallization that I've often seen: The solution collapses, producing a separated liquid and cream. I've known that D-316 is close to the edge of the crystallization-cliff, because I've seen white smudges of the start of crystallization on the bottom of a beaker when mixing it hot (85C). Your test evidently pushed it over the cliff. Congratulations. Actually, this is good news because it gives us a way of stressing a concentrate, and the same test can be done with the final developer. I suspect that the ratio of sodium metaborate to ascorbic acid largely determines vulnerability to crystallization, and the latest developer, 214D, has a lower ratio, so it's hopefully more robust.

Yesterday, I shot and developed an important roll using Delta 400 and 214D. Results are beautiful. Here's an example taken in mediocre indoor lighting at box-speed:



Mark Overton

I noticed that Internet Explorer (IE) sharpens images a little. That makes the picture in my prior posting look sharper and grainier. For this and any other scans on apug, I suggest that IE users right-click the image, save it to a file, and open the file in Windows Picture and Fax Viewer (or a photo-editor). Then you'll see what's really there.

I use Firefox at home, so I didn't notice this sharpening until I came to work. I said to myself, "I don't remember it being that grainy"...

Mark Overton

Mark, now that you have done your fairly involved development work on an XTol-like concentrate, have you any feelings as to what would be the closest-or-better, regular, non-concentrated version, ready for an immediate use, after mixing?

Rafal Lukawiecki said:

Mark, now that you have done your fairly involved development work on an XTol-like concentrate, have you any feelings as to what would be the closest-or-better, regular, non-concentrated version, ready for an immediate use, after mixing?

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Rafal, a simple method would be to mix the formula for 214D directly into water, without the propylene glycol. That would be:


Propylene glycol changes dev-time a little, so removing it means you would need to adjust time. But the big problem with all PC formulas like this is that the Fenton reaction slowly destroys the ascorbate. That means it will last only a few weeks. Kodak solved that problem by adding DTPA to XTOL. But DTPA is difficult to find for ordinary people. Another way to fix this problem is to not put ascorbic acid in it, giving this formula:


This solution will probably last a long time, at least 6 months. But to use this developer, you need to add ascorbic acid separately to your beaker. That's an extra step, so it's not quite "ready to use" which you asked for. If you don't want to weigh the ascorbic acid, it might be easy to measure it with a small measuring spoon.

Back in July 2012, I found that this formula gave the same development-times and same quality as XTOL:


This acted like a clone of XTOL. It was mixed in propylene glycol, so direct-to-water times might change. It's problem was crystallization, so it's not suitable for propylene glycol. But you can also add the ascorbic acid separately with this formula.

Finally, ascorbic acid can be replaced with hydroquinone and sodium metabisulfite. That gives you a long-lasting PQ developer, and there are several good PQ formulas around if you want to try that method. But in those formulas, I suggest replacing Phenidone with 1.3 times as much Dimezone S.

Good luck,

Mark

Thanks, Mark. Out of interest, do you prepare Dimezone S in propylene glycol so as to make it easier to measure such a small amount, or do you just use 0.001 precision scales, which would really mean 0.0001 precision, I suppose? I can see how making the concentrate can be a better proposition, overall, for the consistency of measurement.

Rafal Lukawiecki said:

Thanks, Mark. Out of interest, do you prepare Dimezone S in propylene glycol so as to make it easier to measure such a small amount, or do you just use 0.001 precision scales, which would really mean 0.0001 precision, I suppose? I can see how making the concentrate can be a better proposition, overall, for the consistency of measurement.

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I do both.

I usually mix 2 litres worth of concentrate, and that's enough that I can measure Dimezone S directly using my .001 resolution scale. But for small tests, I use Dimezone S mixed with propylene glycol in a 2% solution like this:

Propylene glycol .......... 49 g (grams, not ml)
Dimezone S ................. 1 g

Then, to get X grams of Dimezone S into a developer, where X is a tiny number, I weigh 50X of that solution, which is much more accurate.

Mark Overton

Thanks Mark. I wish I had 0.001 scales, but I have been using 0.01 so far. An upgrade may happen but your approach in PG makes more sense. I will research how does Dimezone S keep in PG, to avoid failure, and waste.