PDA

View Full Version : Improved version of DS-10 by Ryuji Suzuki?



Pages : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 [18] 19 20 21 22 23 24 25 26 27 28 29

Photo Engineer
01-20-2012, 09:11 PM
Mark;

K2SO3 should equal Na2SO3 in solvent effects. It should also buffer pretty much the same so have you checked the pH of the working solution?

As for Potassium salts, the problem is that they exhaust the fixer more rapidly if one has a sloppy work flow. Too much K ion in a fix will poison it! Bill and I have discussed it and with a good running water rinse or a good fresh stop after the developer or using a one shot fix, there should be no problem.

Of course, K salts are more expensive in the US.

PE

albada
01-20-2012, 11:12 PM
Mark;

K2SO3 should equal Na2SO3 in solvent effects. It should also buffer pretty much the same so have you checked the pH of the working solution?

As for Potassium salts, the problem is that they exhaust the fixer more rapidly if one has a sloppy work flow. Too much K ion in a fix will poison it! Bill and I have discussed it and with a good running water rinse or a good fresh stop after the developer or using a one shot fix, there should be no problem.

Of course, K salts are more expensive in the US.

PE

Ron, thanks for the info. The help is always appreciated!
The pH of this developer was 8.04 before and after I changed the alkalis.
The result of the latest fine tuning of this formula is (for one liter):



Potassium sulfite ............ 100 ml of 45% solution
Ascorbic acid .................. 4.5 g
TEA ................................ 1.7 g (yes, grams)
Phenidone ...................... 0.034 g

Target pH = 8.0. My measured pH = 8.02.
Develop TMY-2 for 13 minutes at 20C.


This formula is where I'm at now. Once I get this fine tuned, I'll switch to Dimezone. Any suggestions for improvements on this approach?
BTW, after developing a 1.5 frame-long strip in 100 ml of that formula, the developer was a little yellow. Its pH was 8.04 afterwards (8.02 before). Might this indicate a capacity-problem? I'm concerned that 250 ml might not have enough capacity for a 36-shot roll.

Mark Overton

Ryuji
01-21-2012, 12:15 AM
after developing a 1.5 frame-long strip in 100 ml of that formula, the developer was a little yellow. Its pH was 8.04 afterwards (8.02 before). Might this indicate a capacity-problem? I'm concerned that 250 ml might not have enough capacity for a 36-shot roll.


Yellow color means ascorbate is oxidized.

Clear solution means ascorbate may or may not be oxidized. Generally speaking, in most plausible reaction pathways, rapid oxidation of ascorbate catalyzed by iron does not always discolor. It more often doesn't.

Triethanolamine does have a mild development accelerating effect other than the pH factor. This effect is even greater with diethanolamine, ethanolamine, methylethanolamine and dimethylethaolamine.

albada
01-22-2012, 09:32 AM
Two surprises with potassium sulfite (used instead of sodium sulfite):


It works unusually cleanly when combined with TEA. Potassium sulfite + TEA appears to act as a mild restrainer, giving low fog even when overdeveloped. The toe seems to be flatter, so there's a slight loss of darkest shadow-detail (and probably speed). I did not get this restraining effect when these alkalis were used separately.
As I mentioned before, PS accelerates development of phenidone+ascorbic and dimezoneS+ascorbic. After some fine-tuning, I find I need about a third less developer to get the same activity.

There's not much of a cost-difference between potassium sulfite and sodium sulfite. I took PhotoFormulary's prices for 1 liter and 1 pound, and got 20 cents versus 16 cents per roll. PS is more convenient, since it comes in a concentrate, but don't forget PE's warning about washing it out in the stop-bath to avoid killing the fixer.

Ryuji: I tried developing again using the light yellow developer, and it worked fine, keeping most (all?) of its activity. But after the 2nd strip, the developer was a light orange! I hold the film-strip in the graduate using a non-stainless steel clip; might iron from that be upsetting the chemistry?

Mark Overton

Ryuji
01-22-2012, 11:43 PM
It works unusually cleanly when combined with TEA. Potassium sulfite + TEA appears to act as a mild restrainer, giving low fog even when overdeveloped. The toe seems to be flatter, so there's a slight loss of darkest shadow-detail (and probably speed). I did not get this restraining effect when these alkalis were used separately.
As I mentioned before, PS accelerates development of phenidone+ascorbic and dimezoneS+ascorbic. After some fine-tuning, I find I need about a third less developer to get the same activity.



Iím not convinced. What you described does not go well with existing knowledge in photographic chemistry. If you are going to assert as you did, I would like to see more details, including statistics of your measurements.



Thereís not much of a cost-difference between potassium sulfite and sodium sulfite. I took PhotoFormulary's prices for 1 liter and 1 pound, and got 20 cents versus 16 cents per roll. PS is more convenient, since it comes in a concentrate, but don't forget PE's warning about washing it out in the stop-bath to avoid killing the fixer.


Potassium salt is less environmentally friendly; it requires more energy to obtain, and then ship. Potassium is also less abundant resource compared to sodium. What you stated above simply suggest to me that Formulary is making less margin with potassium sulfite.



Ryuji: I tried developing again using the light yellow developer, and it worked fine, keeping most (all?) of its activity. But after the 2nd strip, the developer was a light orange! I hold the film-strip in the graduate using a non-stainless steel clip; might iron from that be upsetting the chemistry?


First of all, how do you know the color comes from the oxidation and not from the sensitizing and antihalation dyes from the film?

My developers have powerful stabilizing agent to protect ascorbate from iron catalyzed oxidation, so the worst Iíve seen in actual and reasonable use situation is very pale yellow. I use stainless beaker to adjust the temperature quickly in a water bath, and I also use stainless steel reel and tank for 35mm (Paterson tank for 120/220).

In my past experimentation, if you use a stainless beaker or tank, the iron used in the vessel/apparatus does go in to the solution, although in a tiny amount, and I could easily detect that difference chemically.

Ryuji
01-22-2012, 11:47 PM
Incidentally, in the past, it was said that potassium thiosulfate is a poor fixing agent compared to sodium, and this is probably why a rumor of potassium salt in fix ruins the bath. In reality, thereís no reason to go beyond ammonium or sodium salt anyway, and I could not detect change in clearing time by adding a reasonable amount of potassium sulfite to an ammonium thiosulfate fixing bath. Iím not going to say the rumor was incorrect, but I might say irrelevant.

albada
01-24-2012, 08:54 AM
Incidentally, in the past, it was said that potassium thiosulfate is a poor fixing agent compared to sodium, and this is probably why a rumor of potassium salt in fix ruins the bath. In reality, thereís no reason to go beyond ammonium or sodium salt anyway, and I could not detect change in clearing time by adding a reasonable amount of potassium sulfite to an ammonium thiosulfate fixing bath. Iím not going to say the rumor was incorrect, but I might say irrelevant.

I did some clearing time experiments on samples of my fixer:



Straight fixer: cleared in 3 minutes.
Fixer with .2 ml potassium sulfite concentrate added to 10 ml: cleared in 2.75 minutes.
Above solution after sitting overnight (testing for slow death): cleared in 2.75 minutes.


Conclusion: Potassium sulfite not only does not harm my fixer, it benefits it (reduces clearing time). BTW, my fixer was made by Zone VI Studios, which AFAIK uses sodium thiosulfate. It specifies 5-8 minutes for fixation, so it's not a rapid-type fixer. OTOH, potassium sulfite might destroy other types of fixers, so don't go pouring K2SO3 into your fixer just yet. :)

Mark Overton

albada
01-24-2012, 09:47 AM
I finally got finer grain than XTOL! By a small margin, but finer when carefully compared in a pair of 22X loupes. I only tested it with TMY-2, and this one-liter formula is merely a baseline for further work:



Potassium Sulfite, 45% solution ... 80 ml
Ascorbic acid ........................... 4.5 g
TEA ....................................... 2.7 g (yes, grams; = 2.4 ml)
Dimezone S ............................. 0.067 g

Target pH=8.0. Starting dev-time is twice undiluted-XTOL's time.


On TMY-2, the grain is slightly less clumpy and less stringy than XTOL's, and thus appears more like fine sand in my 22X loupes. Grain also appears slightly finer than XTOL in monotone areas. As mentioned earlier, the toe is slightly lower than XTOL, but the difference is small enough that most people probably wouldn't notice. I'll use this formula as a baseline for more experiments, including (1) using sodium sulfite instead because that's what most people have, (2) reducing sulfite and boosting TEA to reduce chemistry, (3) making a PG-based concentrate out of it, (4) general fine tuning and testing, and (5) other films.

Here are full-resolution crops of neg-scans of TMY-2 in XTOL (left) and this test-developer (right):

45005 - 45006

In both cases, the scanner was manually focused on the "V". Although the scanner can't pick up individual grains, you can see there's less noise in the second scan due to finer grain. Also, I want to take some grain-photos through a microscope and post them, but it'll take some time to get a microscope-setup working.

Mark Overton

Thomas Bertilsson
01-24-2012, 10:03 AM
Nice work.

How are you using Xtol? Stock? 1:1, or even more dilute? Replenished?

Do you print these to see what they do when projected?


I finally got finer grain than XTOL! By a small margin, but finer when carefully compared in a pair of 22X loupes. I only tested it with TMY-2, and this one-liter formula is merely a baseline for further work:


Potassium Sulfite, 45% solution ... 80 ml
Ascorbic acid ........................... 4.5 g
TEA ....................................... 2.7 g (yes, grams; = 2.4 ml)
Dimezone S ............................. 0.067 g

Target pH=8.0. Starting dev-time is twice undiluted-XTOL's time.


On TMY-2, the grain is slightly less clumpy and less stringy than XTOL's, and thus appears more like fine sand in my 22X loupes. Grain also appears slightly finer than XTOL in monotone areas. As mentioned earlier, the toe is slightly lower than XTOL, but the difference is small enough that most people probably wouldn't notice. I'll use this formula as a baseline for more experiments, including (1) using sodium sulfite instead because that's what most people have, (2) reducing sulfite and boosting TEA to reduce chemistry, (3) making a PG-based concentrate out of it, (4) general fine tuning and testing, and (5) other films.

Here are full-resolution crops of neg-scans of TMY-2 in XTOL (left) and this test-developer (right):

http://www.apug.org/forums/attachments/b-w-film-paper-chemistry/45005-improved-version-ds-10-ryuji-suzuki-5-00-xtol-focusvcrop.jpg.att - http://www.apug.org/forums/attachments/b-w-film-paper-chemistry/45006-improved-version-ds-10-ryuji-suzuki-5-26-dimezonefocusvcrop.jpg.att

In both cases, the scanner was manually focused on the "V". Although the scanner can't pick up individual grains, you can see there's less noise in the second scan due to finer grain. Also, I want to take some grain-photos through a microscope and post them, but it'll take some time to get a microscope-setup working.

Mark Overton

Photo Engineer
01-24-2012, 10:38 AM
Very nice work.

My comments about Potassium in the fixer come from comments in Haist and in Mees. I have not personally tested this myself.

The work comes from their comparisons of different salts such as K, Na, NH3 and Ca in fixers and the presumption in some of the literature was that the larger cations made the Silver / Hypo complex more difficult to diffuse.

In fact, there are recent patents that claim that small amounts of Potassium salts actually speed fixing but there is no explanation. My own patent on film Blixes notes an increase of Blix speed with KI present which is counter intuitive.

PE

albada
01-24-2012, 02:14 PM
Nice work.
How are you using Xtol? Stock? 1:1, or even more dilute? Replenished?
Do you print these to see what they do when projected?

Thomas,
I'm using Xtol stock (1+0) one-shot, so that's 6.5 minutes at 20C. I wanted XTOL to show off the finest grain it could. Everything is done at 20C with identically exposed strips.

No printing yet. I have a list of changes to that formula I want to try -- substituting chemicals, changing quantities, dropping pH more, etc. I'd like to see if I can do better, or perhaps do just as well and use less chemistry. In addition, the experiments provide a "feel for the environment" -- an intuition of what effects changes will have. But it takes patience: Once cycle of mix developer/temper bath/dev strip/fix/clean up takes me about an hour. I'm careful and accurate, which is good for repeatability, but such care eats time.

I want to get a densitometer. I'm tired of matching densities by eye, and a densitometer will let me create absolute and relative density-curves, which will clearly reveal loss/gain of speed, contrast/CI, highlight-compression, and anything else relating to tone-levels.

As an aside, I notice that the test-developer image (2nd image) is a bit darker than XTOL's image. Dense areas of the neg's had matching densities, judging by eye through two pieces of paper with a hole punched in each. The difference might be due to auto-exposure in the scanner, which I can't control.

Mark Overton

Thomas Bertilsson
01-24-2012, 02:45 PM
Mark,

Thanks for the explanation.

I find that I get finer grain from Xtol by using it replenished. It's also sharper and has some restraining action in the highlights due to the bromide byproducts (great for portraits). You do lose about 1/3-1/2 stop or so, so the tonality changes somewhat.

I'm impressed with your results. Keep up the great work.

- Thomas



Thomas,
I'm using Xtol stock (1+0) one-shot, so that's 6.5 minutes at 20C. I wanted XTOL to show off the finest grain it could. Everything is done at 20C with identically exposed strips.

No printing yet. I have a list of changes to that formula I want to try -- substituting chemicals, changing quantities, dropping pH more, etc. I'd like to see if I can do better, or perhaps do just as well and use less chemistry. In addition, the experiments provide a "feel for the environment" -- an intuition of what effects changes will have. But it takes patience: Once cycle of mix developer/temper bath/dev strip/fix/clean up takes me about an hour. I'm careful and accurate, which is good for repeatability, but such care eats time.

I want to get a densitometer. I'm tired of matching densities by eye, and a densitometer will let me create absolute and relative density-curves, which will clearly reveal loss/gain of speed, contrast/CI, highlight-compression, and anything else relating to tone-levels.

As an aside, I notice that the test-developer image (2nd image) is a bit darker than XTOL's image. Dense areas of the neg's had matching densities, judging by eye through two pieces of paper with a hole punched in each. The difference might be due to auto-exposure in the scanner, which I can't control.

Mark Overton

Photo Engineer
01-24-2012, 02:47 PM
Just FYI, the Formulary in MT have excellent densitometers for sale. They are unlisted. You can get them with a special order. I have one and it works for both reflection and transmission.

PE

Michael R 1974
01-24-2012, 03:10 PM
As I mentioned in the other thread, can we see some curves? The XTOL negative appears more contrasty to me, therefore we cannot conclude very much regarding graininess. The XTOL negative also appears significantly sharper, which would be the expected trade-off for finer grain.

Interesting process you're going through, though. Definitely a good way to learn. Keep going!


I finally got finer grain than XTOL! By a small margin, but finer when carefully compared in a pair of 22X loupes. I only tested it with TMY-2, and this one-liter formula is merely a baseline for further work:



Potassium Sulfite, 45% solution ... 80 ml
Ascorbic acid ........................... 4.5 g
TEA ....................................... 2.7 g (yes, grams; = 2.4 ml)
Dimezone S ............................. 0.067 g

Target pH=8.0. Starting dev-time is twice undiluted-XTOL's time.


On TMY-2, the grain is slightly less clumpy and less stringy than XTOL's, and thus appears more like fine sand in my 22X loupes. Grain also appears slightly finer than XTOL in monotone areas. As mentioned earlier, the toe is slightly lower than XTOL, but the difference is small enough that most people probably wouldn't notice. I'll use this formula as a baseline for more experiments, including (1) using sodium sulfite instead because that's what most people have, (2) reducing sulfite and boosting TEA to reduce chemistry, (3) making a PG-based concentrate out of it, (4) general fine tuning and testing, and (5) other films.

Here are full-resolution crops of neg-scans of TMY-2 in XTOL (left) and this test-developer (right):

45005 - 45006

In both cases, the scanner was manually focused on the "V". Although the scanner can't pick up individual grains, you can see there's less noise in the second scan due to finer grain. Also, I want to take some grain-photos through a microscope and post them, but it'll take some time to get a microscope-setup working.

Mark Overton

albada
01-24-2012, 03:35 PM
Just FYI, the Formulary in MT have excellent densitometers for sale. They are unlisted. You can get them with a special order. I have one and it works for both reflection and transmission. PE

Can you recommend an economical model? Michael R asked for curves, which I'm also aching to see, and those start with a densitometer.
I'm tempted to hack a 2-3 mm diameter aperture onto an old light-meter to be placed on the neg on the light-table. Perhaps by drilling a hole into its diffusion-dome and painting the dome black.
Do you know if the Formulary sells Stouffer wedges? Or does one buy those directly from Stouffer?

Michael: Those were 1-second exposures, and the tripod was on carpet, so there's a chance there's a bit of motion-blur in there. I'll have to dev a couple more strips and keep an eye out for sharpness.

Mark

Michael R 1974
01-24-2012, 03:51 PM
Not sure where you're located, but I'd be glad to read the densities for you if you need help with this. If you want to buy one, used models can sometimes be had for relatively low prices on eBay etc. I bought my Heiland from Versalab (it does both transmission and reflection) and have found it to be both reliable and easy to use. It was expensive though. I was going through a phase where I did massive amounts of film/developer/ZS testing so I felt it was worth the investment at the time. Now, not so sure! :)

Regarding step wedges, I bought mine directly from Stouffer some years ago. Not sure who else you can buy them from.

Photo Engineer
01-24-2012, 04:06 PM
The Formulary stocks 35mm, 120 and 4x5 Stouffer wedges AFAIK.

PE

albada
01-24-2012, 08:41 PM
Not sure where you're located, but I'd be glad to read the densities for you if you need help with this. If you want to buy one, used models can sometimes be had for relatively low prices on eBay etc. I bought my Heiland from Versalab (it does both transmission and reflection) and have found it to be both reliable and easy to use. It was expensive though. I was going through a phase where I did massive amounts of film/developer/ZS testing so I felt it was worth the investment at the time. Now, not so sure! :) Regarding step wedges, I bought mine directly from Stouffer some years ago. Not sure who else you can buy them from.

Michael, thanks for the offer, but my initial use will be to adjust chemical-quantities and/or dev-times so that test-strips will match the strip produced by XTOL. That means intermittent use of the meter, which I guess means it needs to be here in southern California. Once a formula is looking solid, I'll do some sensitometry with it. For mere density-matching, I might just use a hacked light-meter until I get something better.

PE and Michael: Thanks for the tips on where to get Stouffer wedges.

Mark Overton

Alan Johnson
01-25-2012, 07:36 AM
Why the obscure chemicals very few have?
How about:
Sodium Sulfite to replace Potassium Sulfite,the latter is only used in Pro chemicals because it is very soluble.
Borax to replace TEA, don't need a chelating agent in a concentrate?
Phenidone to replace Dimezone S,it does not hydrolyse at pH 8, I have some Mytol 4 yrs old, still works.

albada
01-25-2012, 10:02 AM
Pertaining to this formula posted yesterday: http://www.apug.org/forums/viewpost.php?p=1291278

Michael R's comment about contrast got me thinking of a way to compensate for the auto-exposure in the scanner. Here are re-scans of the XTOL negative (left) and the test developer (right). The contrasts of the scans are much closer this time.

45044 - 45045

I like to put each image into its own tab in the browser, and then quickly hop between images by clicking on the tabs, thus instantly transitioning between images and making comparison easy.

To answer Alan's question about the rare chemicals: I intend to turn this formula into a concentrate. The potassium sulfite is a convenience because it's already a concentrate. One would mix the two concentrates to make working solution, so no scale would be required (only a graduate). But I intend to formulate a sodium sulfite equivalent because I realize that potassium sulfite is unusual. I think Dimezone S gives slightly finer grain than phenidone, but a switch can be made easily. TEA is readily available here in the States from the photo-chemical suppliers; is it difficult to obtain in the UK? I avoid Borax because it contains much water (bad for a non-aqueous concentrate), but one could use sodium metaborate instead (has only a little water).

Mark Overton