Progress on XTOL-concentrate

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albada

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Photo Engineer said:
Never measure by volume.
Click to expand...

As I learned the hard way.

And I'll repeat this until you're tired of hearing it:
An electronic scale from amazon only costs $15. That's the cost of just 3 rolls of film. There's no excuse not to have one.

Mark
 

Murray Kelly

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50mg of phenidone is 1ml of a 5% solution in alcohol (or anything).


 

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albada said:
I know you're mostly joking, but I went ahead weighed a 6 ml syringe empty and full of HC110, and subtracted, which gave: 7.2 g.
But the ml and weight numbers printed on the side of the bottle work out to 6.3 g.
So something is wrong.

Mark
Click to expand...

I don't see any weight numbers on the photo of an HC110 bottle I have in hand. Any chance you are confusing fluid ounces with weight ounces?

I expect that the best way to do this would be to weigh a full bottle of HC110, then weigh an empty one and to that subtraction. Then divide the result by 473 to get the weight of each ml of concentrate. Finally, multiply that weight by 6.

I'll have to see if I have full and empty bottles in my storage area.
 

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Photo Engineer said:
Careful Matt. Mass assembly of plastic bottles does not mean uniform weight. They may vary by several grams.

PE
Click to expand...

Thanks PE.

This means, sadly that I would have to weigh the bottle before I start using it, and then the same bottle when I am finished.

Darn - that means waiting a long time.

Well at least it isn't Photo-flo
 
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albada

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MattKing said:
Any chance you are confusing fluid ounces with weight ounces?
Click to expand...

Uh oh... (Mark looks up "Fluid Ounce" in Wikipedia). Hey! A fluid ounce is a measure of volume, not weight. Grrr!! That explains the odd result from the numbers on the bottle. Knowing this, the syringe-measurement that says 6 ml of HC110 weighs 7.2 g is probably correct. I expect you to weigh out your HC110 from now on.

Back to D316.
I said in an earlier posting that toes are slightly softer but hard to tell. I saw an unusually soft toe with Delta 400, so I'm running strips on it. The curves:



Red is Xtol; black is D316. Green is D316 but the half of the strip with more flare, and it serves as a second opinion of the toe. That toe is enough longer that it concerns me. D316's grain is finer, but would this longer toe cause significantly darker shadows than Xtol?

Mark
 
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albada

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I realized that I could also measure the higher-flare half of the Xtol strip. Here are the Xtol-D316 curve-pairs. The left graph is with minimal flare; the right graph is with more flare but still shows the shape of the two toes.



This gives you two comparisons of the toes of Xtol versus D316.

Mark Overton
 
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albada

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I made two discoveries this weekend.

1. The toe in Delta 400 can be shortened to match Xtol by reducing ascorbic acid (AA) to 3.7 g or lower. D316 uses 4.5 g, and I tested 3.0, 3.5, 3.7 and 4.0 g this weekend. At 3.7 g, sodium metaborate must be reduced to about 1.7 g. This raises pH some to compensate for loss of activity due to reduced AA. Grain is still at least as good as Xtol. BTW, my test-strips contain two frames each, so I can measure two toes in each test, giving me more confidence that I didn't see an anomaly.

2. Even with reduced buffering due to reduced alkali and acid above, highlights and shoulder were identical. I finally realized why: The shoulder is caused by the limited diffusion-rate of the gelatin. I designed my developer to have a higher devtime-to-phenidone ratio than Xtol. As a result, my dev needs a lower diffusion-rate than Xtol (which I never thought about). So it hits the diffusion-limit at a higher density. Hence the higher shoulder. (PE, please correct me if I'm off in the weeds here).
This gives me an idea of how to make a developer that's good for pushing: Reduce that ratio so much that even midtones sag. That will give the toe-area time to develop more while taming overall contrast.

3. I'm happy because I killed the gopher that was tearing up my back yard. Oh, this is off-topic...

Mark Overton
 

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The specific gravity of HC-110 is 1.24 from the MSDS. So 6 ml should weight 7.44 grams.
 

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albada

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Gerald C Koch said:
The specific gravity of HC-110 is 1.24 from the MSDS. So 6 ml should weight 7.44 grams.
Click to expand...

My 6 ml syringe pulled in 7.2 grams. That gives you an idea of how inaccurate volume-measurements are. As PE said, "Never measure by volume."

Mark
 
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albada

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Trial-130119

After running more tests, I've come up with the following modification to D316 which gives a tighter toe with Delta-400. The 1-litre formula:

Propylene glycol ....................... 10 g (yes, measured in grams)
Sodium metaborate 4 mol ........ 1.5 g
Ascorbic acid ............................ 3.5 g
Phenidone ................................ 0.05 g

Use 14.7 g/L of concentrate with 50 g/L of sodium sulfite. pH = 8.18.
​

I'm calling this formula "Trial-130119", as that's the date of the first mixing (yesterday). This is also more concentrated than D316. It is very close to something I mixed 4 months ago, so it should not crystallize, but we'll know for sure in a couple of weeks. Note that I raised the sulfite from 45 to 50 g. That was solely to raise pH, but I might drop it back to 45 g. The time for Delta-400 is the same as D316 (17 min), and we'll see how times for other films are affected.

Grain is still a bit finer than Xtol, despite Xtol having the advantage of lower contrast. The scanner was manually focussed on the middle wedge and contrast adjusted to be equal:
Xtol: Trial-130119:

And the curves. Note that the toe is identical to Xtol:


As with D316, highlights are stronger than Xtol.

Fog is higher than Xtol. I noticed D316 produced a bit higher fog with a few films. Trial-130119 behaves the same. My experiments indicate that the fog is likely due to sodium metaborate mixed into propylene glycol, which Gerald Koch said produces esters. Could those esters boost fog? With both D316 and Trial-130119, Delta-400 has 0.12 more fog than Xtol, which is a lot. Fortunately, the scans show that grain is not affected. Maybe add a restrainer anyway?

So why am I fooling with this after burning over 50 rolls testing D316? Because I'm a perfectionist! Those tests showed that D316 had slightly softer toes with a few films, but Delta-400 already has a somewhat soft toe, and I am loath to make it any softer. Delta-400 is an important film, so I want my dev to work well with it.

Mark Overton
 

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albada said:
My 6 ml syringe pulled in 7.2 grams. That gives you an idea of how inaccurate volume-measurements are. As PE said, "Never measure by volume."
Click to expand...

Mark, don't be mislead. It's fine to measure by volume when appropriate. After all, most people probably measure their water, or at least the final mix size, by volume.

Your discrepancy just tells me that either your syringe or the MSDS statement of specific gravity probably isn't all that accurate. Maybe even your scale. Without some way to crosscheck your gear, it's hard to know exactly which part is off.

Even so, your ~3% discrepancy is probably not too big a deal. (It would be nice to know the significance, though.)
 
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A question for the chemists here:
Why do I *not* get precipitation when freezing these PG-based concentrates? I put Trial-130119 in the freezer overnight, and like D316, there is no cloudiness nor precipitate. Based on lack of precipitation, I recommend that these be frozen. But I'm wondering: why no precipitate?
Trial-130119 takes longer to dissolve the ascorbic acid at 75C due to its higher concentration and lower proportion of metaborate. So I'm closer to the solubility limit. Yet no precipitation when frozen. Odd.

@Mr Bill - Thanks for the note. You're right, and I hadn't thought of that: I still measure the water by volume because it's impractical to weigh such a large volume and a beaker is accurate enough.

Finally, the curve for Trial-130119 with 45 g/L of sulfite (reduced from 50 g/L in my prior posting) has this curious trait: The toe matches Xtol, and the highlights match D316. Here are all three curves for Delta 400:



The toes are the means of two frames, and my goal of all this was to remove the softness in the toe of the green curve (D316).

Mark Overton
 
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Some surprising (and good) results:

1. The Trial-130119 developer (described 3 postings back) will also accept Dimezone S without crystallizing. At least it's now been a week with no evidence of crystallization, and I'll truly believe it when it's gone one month. D316 quickly crystallizes with Dimezone S. I used 0.1 g of Dimezone S in place of 0.05 g of Phenidone. Based on resulting dev-times, I should have used 0.096 g of Dimezone S to keep dev-times the same as Phenidone. With 0.1 g, dev-times must be reduced by 4%.

2. The Dimezone S version produces finer grain and lower fog. I only tested Delta 400 because I've found it's unusually sensitive to developer composition. Here are scans of strips developed in XTOL, D316, Trial-130119/Phenidone and Trial-130119/Dimezone. The contrast of these scans was boosted digitally to exaggerate differences in grain:

XTOL: D316: T119/Phen: T119/Dime:

To me, the T119/Dime is noticeably better than the others. Clue: Once you've viewed the images, you can quickly switch between them, and the instant image-changes make grain-comparison easy.
The curves of this brew versus XTOL show a good match with the usual higher shoulder:



I was surprised that it did not crystallize with Dimezone S. I suspect the lower metaborate/ascorbic ratio is the reason. It obviously is not related to concentration-ratio because Trial-130119 is more concentrated than D316.

Fog was another surprise. Simply switching from Phenidone to Dimezone S dropped fog by 0.1 log-units (1/3 stop). That's a lot. Delta 400 has higher fog than most films, and metaborate/glycol/Phenidone worsen it. But merely switching to Dimezone S dropped the fog down to XTOL's level (0.38). I like Dimezone S. PE says it stores better, and I find it also gives better image-quality.

I think my next step will be to mix new concentrate using 0.096 g of Dimezone S and verify that image-quality is unchanged with the longer dev-times.

Mark Overton
 
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albada

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After reading the above posting, I realized it's hard to compare Trial-130119/Dimezone with XTOL because they're separated by two images. Here they are together, so you can switch back and forth between them with one click:

XTOL: T119/Dime:

Some more ideas I have are to (1) eliminate the crystallization issue by replacing metaborate with TEA, because I doubt there will be much difference between 85% and 99% TEA, (2) replace some of the poorly-soluble ascorbic acid with better-soluble hydroquinone to maintain a high concentration-ratio, and (3) adjust pH downward with citric acid. Too many ideas to try and too little time...

Mark Overton
 

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Be careful Mark, 85% TEA is usually 15% DEA making the mixture more alkaline than 99% TEA. This will throw off the pH of the developer.
 

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But if the results are good, then why worry as long as you disclose the full details to the readers. Right?

PE
 
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albada

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Gerald C Koch said:
Be careful Mark, 85% TEA is usually 15% DEA making the mixture more alkaline than 99% TEA. This will throw off the pH of the developer.
Click to expand...

Thanks for the warning. I happen to have both kinds of TEA here, so I'll make it a point to test with both. Hopefully as PE says, the difference will only amount to a note like "for 85% TEA, reduce times by 4%" or similar.

I've tested Trial-130119 with both Tri-X and Delta-400 using Dimezone S. Compared with XTOL, this Trial dev gives the same or a hint worse grain with Tri-X, and noticeably finer grain with Delta-400. Ilford is committed to this market, so I'm making certain that whatever I come up with works well with their films.

Mark Overton
 

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Alan Johnson said:
Dimezone-S= No shipping by mail or outside the USA,UPS ground only (Photoformulary).
Click to expand...
If you are located in Europe, Fototechnik Suvatlar sells it ... all hope is not lost if PF doesn't ship.
 
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albada

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Alan Johnson said:
Dimezone-S= No shipping by mail or outside the USA,UPS ground only (Photoformulary).
Click to expand...

FIXED: THEY WILL NOW SHIP IT EVERYWHERE.

I emailed Photoformulary and they fixed this mistake. Check their website now, and you'll see no shipping-restriction on Dimezone S. Emails are below.

Mark Overton

-------------- Emails -------------------

Hi Mark
I have updated the Dimezone S. All should be better now.
Sherry

----- Original Message -----
From: Overton, Mark
To: sherry@photoformulary.com
Sent: Monday, February 04, 2013 1:12 PM
Subject: Wrong MSDS for Dimezone-S, plus shipping-restriction mistake

Hi Sherry (or whomever),

1. The MSDS on your web site for Dimezone S is for some moderately dangerous liquid, and not for Dimezone S which is a powder.

2. Shipping for Dimezone S is USA-only UPS-Ground-only. That’s also probably a mistake based on the MSDS above. Dimezone S is a powder of low toxicity.

Some folks in Europe would like to buy Dimezone S from you, but they can’t because of the shipping restriction. Correcting these errors would boost your sales of Dimezone S.

Thanks,

Mark Overton
 
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albada

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Good news: It’s been three weeks, and there is still no evidence of crystallization in the Dimezone-version of Trial-130119. In the past, I’ve always seen crystallization start within a week or two, so it’s probably stable.

Crystallization seems to be a function of the alkalinity of the concentrate, and that’s controlled by the ratio of sodium metaborate (SM) to ascorbic acid (AA). D316’s SM/AA-ratio is 2.2/4.5 = 0.489. Trial-130119’s ratio is 1.5/3.5 = 0.429. I’ve noticed a white smudge on the bottom of the beaker when mixing D316 at temperatures over 80C. That’s the beginning of crystallization, so D316 is on the border. I believe Trial-130119 backs off some from that border, which is enough to allow the use of Dimezone S.

I think I’ll abandon Phenidone and use Dimezone S instead. Here’s why:

1. Dimezone S is obtainable everywhere for a reasonable price. PhotoFormulary.com now ships it world-wide. So does Fototechnik Suvatlar, and thanks to Rudeofus for pointing that out.
2. Dimezone S gives a sharper toe with some films. Delta 400 in particular has a significantly softer toe with Phenidone, unless the AA is reduced so the AA/Phenidone ratio is about 70. Dimezone S maintains the sharper toe in the presence of more AA.
3. Dimezone S gives normal fog when used in glycol-based concentrates. For Delta 400, Phenidone raises fog as much as 0.10. For most films, Phenidone’s glycol-induced fog-rise is around .07-.08, but it’s as low as .02 for a few films such as Tri-X and Tmax-400.
4. Dimezone S stores better.
5. Dimezone S’s image-quality is at least as good as Phenidone.
6. It looks like the crystallization problem with Dimezone S has been solved.

I can see no reason to use Phenidone. Do you?

Mark Overton
 
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