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Thread: DS-12 stock?

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    DS-12 stock?

    I'm about to try Ryuji Suzuki's formula for DS12 (http://silvergrain.org/Photo-Tech/fi...recommend.html). Unfortunately he does not give a recommendation for stock solutions of DS-12. Weighing in such small amounts to make one-shot solutions evere time I need them sounds a bit inconvenient.

    What do you think? Does it sound reasonable to make up a tenfold concentrated stock or would this be overdoing it? Should I stick with fivefold? Any additional precautions?

    thanks in advance

    Stefan

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    Speaking from limited experience, I would say tenfold concentrate should work, but more will be tough because of the sulfite. Raising the mixing temp. to 35C is probably a good idea. You could probably e-mail Ryuji himself - his address is on the web site.

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    Quote Originally Posted by skahde
    Unfortunately he does not give a recommendation for stock solutions of DS-12. Weighing in such small amounts to make one-shot solutions ...

    What do you think? Does it sound reasonable to make up a tenfold concentrated stock or would this be overdoing it? Should I stick with fivefold? Any additional precautions?

    Stefan
    I never weigh less than a gram of anything on my .01gr Acculab.
    I would make a fivefold stock useing one gram metol. That will
    leave you with 1/2 liter. That would do me five rolls of 120 at
    1/2 liter/roll.

    I seem to recall that sulfite is not all that soluable. I've doubts 50gr
    of it will fit into 1/4 liter. Never raise the temperature to dissolve unless
    you know that the amount dissolved will remain in solution after it has
    cooled and perhaps cooled for some time.

    BTW, have you any idea why the triethanolamine? Also what is the
    DS-2 he speaks of and do you know where the formula might be?

    DS-12 is likely very similar to FX-1. If so it will also make a good paper
    developer. Dan

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    Quote Originally Posted by dancqu
    I never weigh less than a gram of anything on my .01gr Acculab.
    I would make a fivefold stock useing one gram metol. That will
    leave you with 1/2 liter. That would do me five rolls of 120 at
    1/2 liter/roll.

    I seem to recall that sulfite is not all that soluable. I've doubts 50gr
    of it will fit into 1/4 liter. Never raise the temperature to dissolve unless
    you know that the amount dissolved will remain in solution after it has
    cooled and perhaps cooled for some time.

    BTW, have you any idea why the triethanolamine? Also what is the
    DS-2 he speaks of and do you know where the formula might be?

    DS-12 is likely very similar to FX-1. If so it will also make a good paper
    developer. Dan
    Dan, take a look in the Chemistry Recipes section. I have mixed up concentrated TEA (as the solvent) versions of Suzuki's DS-14 (Phenidone/Ascorbic Acid) and DS-15 (Metol/Ascorbic Acid). They are paper developers, but at high dilutions they should be pretty close to Xtol (or Gainer's PC-TEA). I am in the process of testing them.

    I avoided the sulfite solubility problem by adding the sulfite, carbonate and KBr to the water used to prepare the working developer. Adding the carbonate may not have been necessary - but I don't see how it can hurt.

    BTW, I had no difficulty at all dissolving 6 grams of Metol in 350ml of TEA at 240 F.
    Tom Hoskinson
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    Quote Originally Posted by dancqu
    I seem to recall that sulfite is not all that soluable. I've doubts 50gr
    of it will fit into 1/4 liter.
    A table of solubilities that I copied from the web a couple of years ago said 313g sodium sulphite will dissolve in 1Litre of water at around room temp. I haven't tested that, but I keep a 200g/L solution as a stock solution for rinse aid.

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    Quote Originally Posted by john_s
    A table of solubilities that I copied from the web a couple of years ago said 313g sodium sulphite will dissolve in 1Litre of water at around room temp. I haven't tested that, but I keep a 200g/L solution as a stock solution for rinse aid.
    That sounds about right for solubility of sodium sulfite in water.

    In alcohols, glycols and triethanolamine (TEA) it is only slightly soluble.
    Tom Hoskinson
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    Everything is analog - even digital :D

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    Quote Originally Posted by skahde
    I'm about to try Ryuji Suzuki's formula for DS-12 ...
    Stefan
    A few odds and ends:

    I'm quite sure DS this and that are Suzuki formulas.

    At www.pofig.com you will find the formula for DS-2. Metol, ascorbic
    acid, and sulfite are as with DS-12.

    There is a .2 gram complexing agent in DS-12 as well as triethanolamine.
    I think Mr. Suzuki is throwing us a curve with that one as he is using
    it as an alkali. He uses a bicarbonate/carbonate combination in DS-2.

    As for the solubility of sodium sulfite; in my work I may have bumped
    up against the "practical solubility in H2O" of 150 grams/liter mentioned
    at www.genchemcorp.com. Otherwise the amount soluble varies. With
    time 200 grams will likely fit in one liter making for a ten-fold. Dan

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    Quote Originally Posted by skahde
    I'm about to try Ryuji Suzuki's formula for DS12 (http://silvergrain.org/Photo-Tech/fi...recommend.html). Unfortunately he does not give a recommendation for stock solutions of DS-12. Weighing in such small amounts to make one-shot solutions evere time I need them sounds a bit inconvenient.

    What do you think? Does it sound reasonable to make up a tenfold concentrated stock or would this be overdoing it? Should I stick with fivefold? Any additional precautions?
    I'm using DS-12 for several month now and think it gives excellent results with APX100 and the slower Efke films. I routinely dissolve 10x the amount of given chemistry in 900ml water at 40deg. Celcius, this works like a charm. After dissolving everything (I use a magnetic stirrer) I top it up to 1l and use 25ml per film + 225ml water. Stored at room temperature, I had no precipate yet.

    On my website http://www.jangowski.de/sensitometry/ I have several test results with DS-12 used like that. To get maximum sharpness, I made all these tests with 30s agitation first and 10s every two minutes after that. However, being lazy, I recently tried DS-12 in my ATL and found that the results with APX100 are essentially identical with about 20% less time. With 6x6 enlarged to 30x30cm, the sharpness seems identical, no real need for manual work ;-)

    Martin

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    Thanks so far to everyone who responded!

    "However, being lazy, I recently tried DS-12 in my ATL and found that the results with APX100 are essentially identical with about 20% less time. With 6x6 enlarged to 30x30cm, the sharpness seems identical, no real need for manual"

    Martin, do I understand this one correctly: http://www.jangowski.de/sensitometry/APX100.jpg
    At 24°C you get less speed/lowered shaddow density as compared to 20°C. This would be very interesting as I started to optimize everything for the higher temperature which is far easier to maintain in the warmer half of the year.

    Maybe I shouldn't do that...

    regards

    Stefan

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    Quote Originally Posted by skahde
    Thanks so far to everyone who responded!

    "However, being lazy, I recently tried DS-12 in my ATL and found that the results with APX100 are essentially identical with about 20% less time. With 6x6 enlarged to 30x30cm, the sharpness seems identical, no real need for manual"

    Martin, do I understand this one correctly: http://www.jangowski.de/sensitometry/APX100.jpg
    At 24°C you get less speed/lowered shaddow density as compared to 20°C. This would be very interesting as I started to optimize everything for the higher temperature which is far easier to maintain in the warmer half of the year.
    The third curve with 24deg. was made with DS-10, a developer obviously not very suited to APX100. I use DS-10 1+1 at 24deg. to keep the times reasonable.

    Martin

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