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



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Ryuji
12-29-2011, 07:02 PM
The formula type is new to APUG as far as I know.
But it is unbuffered, see posts #25 and #26 in this thread.
It may oxidize to the more acidic(I think) dehydroascorbate and fall in pH.
But one would have to do a long term comparative test with Xtol, both in contact with air,to see.

Think about it from the other side. Why didn't Kodak sell this simplified formula rather than XTOL? It'd certainly be cheaper to manufacture. The answer is that it would be a quality control nightmare and customer service disaster.

Keith Tapscott.
12-30-2011, 07:50 AM
Think about it from the other side. Why didn't Kodak sell this simplified formula rather than XTOL? It'd certainly be cheaper to manufacture. The answer is that it would be a quality control nightmare and customer service disaster.What film developing times do you suggest to start with DS-10 and your DS-12 developers Ryuji?
I don't fancy wading through 23 pages of a long thread today to find out. :D

analog what is that?
12-30-2011, 07:59 AM
Or to put it differently: do you have a web-site or some PDF-files to download on your DS-10 and DS-12, with recdipes and recommended times?
Some of the chatter doesn't exactly offer enlightenment, and yes I'm partly to blame! :-)

albada
12-30-2011, 09:49 AM
Or to put it differently: do you have a web-site or some PDF-files to download on your DS-10 and DS-12, with recdipes and recommended times? Some of the chatter doesn't exactly offer enlightenment, and yes I'm partly to blame! :-)

Part of the answer is on the digitaltruth website:


DS-10 info: http://www.digitaltruth.com/data/ds-10.php
DS-12 info: http://www.digitaltruth.com/data/ds-12.php


These give you the formulas. Unfortunately, each formula has only one suggested starting-time. In addition, DS-10 has a couple of entries in the massive dev-chart here (http://www.digitaltruth.com/devchart.php?Film=&Developer=DS-10&mdc=Search).

Mark Overton

JaZ99
12-30-2011, 10:06 AM
There is the original page archived: http://web.archive.org/web/20091005194807/http://silvergrain.com/labs/Film_Developer_Recommendations

Keith Tapscott.
12-30-2011, 10:33 AM
I should have wrote that I would be interested in the times for Ilford HP5 Plus with both the stock-strength developer and the 1+1 dilution.

Photo Engineer
12-30-2011, 11:31 AM
Mark;

It would help if you scanned in the two samples (XTOL vs your developer) to give a visual example for all of us. It might also help if you tested a few other films with the developer to show its generality to emulsions. It would also give others a feel for the correct development times.

PE

RidingWaves
12-30-2011, 09:31 PM
Well, who knows? Maybe kodak Did start with such a simple formula and then thru the process of fixing the challenges and Wah-Lah, XTOL.

Ryuji
12-31-2011, 02:28 AM
Guys, sorry I had to take the silvergrain labs site down. The software platform was complicated and too costly to maintain, plus I make living shooting photography not maintaining websites or sharing information. If there's demand maybe I could make an e-book or something... but seriously I need interns to do that.

Regarding DS-12, this formula has not been in use for some time. However, I've devised a formula that perhaps could be described as roughly halfway between DS-10 and 12, or perhaps better way to say it might be an ascorbate version of Microphen/DD-X. This film developer gives grainless and sharp image with 35mm TMX or Acros in 20x24 enlargement (and gives at least box speed at normal contrast). This was once prepared as liquid concentrate. I actually had many bottles of this developer, manufactured and packaged in my previous lab space in Downtown Boston, and ready to ship out as commercial samples... but now I'm reformulating it in all powder form. I'm actually eager to test it with 400TMY-2. I actually never shot 400TMY-2, but that seems to be one obvious thing to try, since what I want to do with film now requires best IQ and speed.

But please be patient. I'm not interested in spending all day discussing trivial matters on chemistry. I'm interested in creating images and furnishing myself with necessary technology. When this developer in question is prepared, tested in my new studio, you'll hear from me somehow.

albada
12-31-2011, 03:53 PM
At PE's suggestion, I scanned the test-strips for XTOL (6.5 min at 20C for TMY), and for the concentrate shown below, which was posted earlier in this thread here (http://www.apug.org/forums/viewpost.php?p=1276385):




Propylene glycol ................. 39 ml
Ascorbic acid ..................... 10.7 g
Sodium metaborate ............. 6.5 g
Phenidone .......................... 0.15
Propylene glycol to ............. 50 ml (you should only need to add about 1 ml)


This should be diluted 1+19, making 1 liter of working solution. My dev-time was 7.5 min at 20C for TMY.

Here is the XTOL scan:
43614 And a crop: 43615

And here is the scan of the above formula:
43616 And a crop: 43617

These images are darkish because I set the white-point as high as possible in the scanner, to clip as little data to white as possible (i.e., maximize the dynamic range). The black-point was set to the left side of the histogram (which was always the same). Gamma was 1.5.
This is part of my camera-collection, lit by the overhead tungsten candelabra. It's hard lighting, which creates plenty of specular reflections to see how the dense part of negatives are doing. Unfortunately, my Coolscan IV ED scanner doesn't have enough dynamic range to cover such specular reflections well (and still show shadow-detail in the neg's), so many reflections clip to white.

In the crops above, my formula appears to have less grain than XTOL. That's not true. In 22X loupes, they seem to have the same grain. The scanner's focus has a little variation, and the film isn't held perfectly flat, so grain is defocussed by unpredictable amounts. To get sharp images of grain, I want to photograph negatives in a microscope.

Mark Overton

Photo Engineer
12-31-2011, 04:08 PM
Thanks Mark;

IMHO the experimental developer looks less sharp. Look at the numbers on the lens in both crops. The grain is similar and low.

PE

albada
12-31-2011, 04:28 PM
Thanks Mark;
IMHO the experimental developer looks less sharp. Look at the numbers on the lens in both crops. The grain is similar and low.
PE

Oops, that was poor scanner-focus, being near the edge of the neg-carrier.
I re-scanned that neg, but this time manually focusing the scanner on that crop-area. That made the scan sharper there:

43622

Mark Overton

Photo Engineer
12-31-2011, 07:47 PM
Thanks again. Looks better now. There is some "hash" on the right top in the dense areas.

Both developers look similar in contrast to me when viewed as thumbnails. I can't view them side-by-side for a more accurate examination. Just keep on working. looks interesting and you are learning as you go.

PE

albada
01-02-2012, 07:54 PM
Here's a failure I'd like some advice about.

Moving toward creating a concentrate, I modified the PC-Sulfite formula by replacing the sodium sulfite with TEA. The big difference between this and PC-TEA is the pH is much lower, and thus there's more AA and phenidone per liter to keep the dev-time at 7-8 minutes. Here's the 1-liter test-formula:


TEA ................. 5 ml
Ascorbic acid ... 2.7 g
Phenidone ....... 0.18 g
pH = 8.3


The AA and phenidone are about the same as PC-Sulfite, and the pH is the same. So I expected the dev-times to be the same. But 7.5 min at 20C produced a very thin test-strip. A second strip at 9.5 minutes was also thin, plus the developer had turned light yellow. Adding a little more ascorbic acid made it clear again.

I even tried quadrupling the TEA and AA (keeping the pH at 8.3), and an 8 minute time gave negatives that were a little thin, and yellowish developer again. It seems that the developer is quickly becoming exhausted or oxidized.

Any idea why?

I know that sulfite is an antioxidant, but ascorbic acid is an even stronger antioxidant, so I'm surprised that swapping out the sulfite caused this.
Further mysterious is the fact that PC-TEA does not exhibit this problem, and it has even less AA and phenidone per liter than my formula above. However, PC-TEA operates at a high pH around 10, and I'll speculate that that high pH is activating the phenidone in PC-TEA rather than the AA. But that's just my speculation...

Mark Overton

Photo Engineer
01-02-2012, 08:43 PM
Mark;

Perhaps you have missed the buffer capacity of the Sulfite compared to TEA among other things, and that involves the molecular weights as well. Look at the moles per liter of TEA and Na2SO3.

PE

albada
01-02-2012, 09:09 PM
Perhaps you have missed the buffer capacity of the Sulfite compared to TEA among other things, and that involves the molecular weights as well. Look at the moles per liter of TEA and Na2SO3.


I forgot to mention: The pH was the same after development as it was before (8.3). I checked this on the second run wondering the if pH had plunged. I even checked pH once a minute while developing a leader -- always at 8.3. So I don't think poor buffering is the culprit.

Sulfite and TEA have similar molecular weights: 126 vs 149. So even after quadrupling, I was putting far fewer moles/liter in there. But given that pH is constant, I don't know what harm fewer moles of alkali would do.

Mark Overton

Photo Engineer
01-02-2012, 09:42 PM
Mark;

The pH does not give one the buffer capacity. They are not the same. One refers to the inertia of the movement of the pH with any addition of acid and the other refers to just an absolute number of Hydrogen or Hydroxyl ions present. So, Na2SO3, if it ionizes more fully than TEA even at the same weight, will probably buffer better. That is poorly stated but gives a gist of the situation.

Since SO3-- puts more Ag+ into solution being a mild solvent, a mix of DEA/MEA/TEA might simulate SO3--. IDK. Try it. I have my own solutions to this problem. :D

PE

Alan Johnson
01-03-2012, 02:38 AM
Here's a failure I'd like some advice about.

Moving toward creating a concentrate, I modified the PC-Sulfite formula by replacing the sodium sulfite with TEA. The big difference between this and PC-TEA is the pH is much lower, and thus there's more AA and phenidone per liter to keep the dev-time at 7-8 minutes. Here's the 1-liter test-formula:


TEA ................. 5 ml
Ascorbic acid ... 2.7 g
Phenidone ....... 0.18 g
pH = 8.3


The AA and phenidone are about the same as PC-Sulfite, and the pH is the same. So I expected the dev-times to be the same. But 7.5 min at 20C produced a very thin test-strip. A second strip at 9.5 minutes was also thin, plus the developer had turned light yellow. Adding a little more ascorbic acid made it clear again.


Mark Overton
I made up this solution in tap water and measured its pH.
I get pH= 8.0 with an inexpensive pen type meter,but it calibrates accurately vs 2 buffers.
btw there are 2 types of TEA, 97% and 99% and they have different pH. I used 97%.
So partly pH may be a factor in your result. Also, not mentioned, sulfite is known to dissolve some silver halide and uncover latent image centers which TEA may not do and this may be a factor as well.

albada
01-03-2012, 09:26 AM
I get pH= 8.0


This pH-difference might be due to measurement-variations. I mix 200 ml test-solutions, and divide the formula by 5. For this, that means 1 ml of TEA and about 1/2 gram of AA. The 1 ml of TEA makes the pH swing a long distance, from 3.0 to 8.3. That's a range of 8.3-3 = 5.3. A shift of 0.3 represents a 6% shift over that range. For small liquid quantities, I use a syringe with a 3 ml capacity, and which is graduated in 0.1 ml increments. I can probably get within 0.05 ml with it. That's a 5% random variation in my measurement right there. So your 8.0 versus my 8.3 is probably due to measurement-variation.

Did you try a clip test with this formula? Even 10 minutes at 21C gave me a thin clip.

Mark Overton

Rudeofus
01-03-2012, 11:55 AM
Mark,

could you find out whether that clip ever turns normal if you dev long enough? PE suggested in some previous post that at EK they investigated slow developer for extra fine grain. Since your pH seems to linger around the lowest possible value for B&W dev (according to what Ryuji posted), you may have inadvertently walked the path Ron suggested.

About your pH measurements: nobody expects your whole liquid to change pH from the couple of silver grains reacting with your dev, but locally the pH could change thereby reducing contrast (similar to stand development). The easiest way for you to find out is by changing agitation: if strong agitation creates much thicker negs, some local effect may be the culprit and buffering could help.

If your test clip turns normal after much longer dev, it would be interesting to see results, especially with regard to grain. On the one side you achieved extra slow development, on the other side you omitted Na2SO3 which acts as a grain solvent.