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#1
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102 print developer storage as working solution
September 27, 2007, from Lloyd Erlick,
Recently I posted regarding a print developer I've been playing with lately: Edwal 102 (Potassium version). On Sept. 19, I made up a working solution of 102, according to the formula I posted. I made a couple of prints that day. After this, I stored the developer in a sealed plastic bottle, filled nearly to the brim. On Sept. 20, I used the developer again, for a small number of prints. I stored the developer again. On Sept. 26, I used the developer to make four prints. I had the same negative in the enlarger as on Sept. 20, and I used the same exposure settings. The prints were visually the same on both dates. As usual, I didn't perform scientifically exact measurements, but the prints looked the same to me. All the prints, from fresh developer and week old, show very dense blacks and lovely tonality in the skin tones. My test picture involved a blonde person posed against a black background, and the hair worked out very nicely. Anyway, I'm a little surprised to find a developer that keeps a week in the form of a partially used working solution. In fact, I'm amazed and wondering if this isn't too good to be true. Could this be the reason Edmund Lowe (who invented this developer) specified phosphate in the formula? Is this part of the reason it keeps well? Edwal 102 (Potassium version) is a very good developer for portrait work on warm-tone print material. I've been using Ilford Warmtone FB paper (Ilford calls it MGW) and the results after selenium toning are very beautiful. This actually raises an interesting "difficulty" -- Glycin does not keep well in dry powder form, and if a working strength developer solution will keep well, the length of time required to use up the supply of Glycin is extended. I bought 250 grams, which is starting to look like much too much for one time. I've heard there are ways to keep Glycin in solution form better than in powder, but I've never learned details or tried it myself. Oh, I just thought of a question for the old time experienced crew: would the ancient practice of 'sweetening' or 'seasoning' a freshly mixed batch of this developer with ten or twenty per cent by volume of week-old working solution be of any value? I've tried this on several occasions with other developers, and I have to admit I've never seen the benefit. regards, --le ________________________________ Lloyd Erlick Portraits, Toronto. website: www.heylloyd.com telephone: 416-686-0326 email: ________________________________ -- |
#2
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102 print developer storage as working solution
"Lloyd Erlick" Lloyd at @the-wire. dot com wrote
Edwal 102 (Potassium version). Something like: H20 1l P.Sulfite 100g TSP 125 Glycin 25 P. Bromide 3 (?) I'm a little surprised to find a developer that keeps a week in the form of a partially used working solution. I believe it is Metol that's responsible for short tray life. Metol-less HQ, Glycin and Phenidone developers seem to last longer. Phenidone is often kept dissolved in 90+% isoproponol. I don't know if this is works with Glycin, I seem to remember Patrick Gainer mentioning Propylene Glycol as a keeping solvent. It is possible that a 1:4 liquid concentrate of Glycin and S. Sulfite would keep a long time. My guess is the actual ingredients of a bottle of Glycin are somewhat variable - in my experience it sometimes goes quickly, sometimes it lasts for a year. Oh, I just thought of a question for the old time experienced crew: would the ancient practice of 'sweetening' or 'seasoning' a freshly mixed batch of this developer with ten or twenty per cent by volume of week-old working solution be of any value? I've tried this on several occasions with other developers, and I have to admit I've never seen the benefit. TTBOMK this is a practice used for motion picture developing where they want to keep the activity of the developer constant from the last film through a tank of old developer to the first film through a tank of fresh developer. Richard Knoppow would know: "Knoppow Knows" - does that count as nominative determinism? -- Nicholas O. Lindan, Cleveland, Ohio Darkroom Automation: F-Stop Timers, Enlarging Meters http://www.darkroomautomation.com/index.htm n o lindan at ix dot netcom dot com |
#3
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102 print developer storage as working solution
"Nicholas O. Lindan" wrote in message ... "Lloyd Erlick" Lloyd at @the-wire. dot com wrote Edwal 102 (Potassium version). Something like: H20 1l P.Sulfite 100g TSP 125 Glycin 25 P. Bromide 3 (?) I'm a little surprised to find a developer that keeps a week in the form of a partially used working solution. I believe it is Metol that's responsible for short tray life. Metol-less HQ, Glycin and Phenidone developers seem to last longer. Phenidone is often kept dissolved in 90+% isoproponol. I don't know if this is works with Glycin, I seem to remember Patrick Gainer mentioning Propylene Glycol as a keeping solvent. It is possible that a 1:4 liquid concentrate of Glycin and S. Sulfite would keep a long time. My guess is the actual ingredients of a bottle of Glycin are somewhat variable - in my experience it sometimes goes quickly, sometimes it lasts for a year. Oh, I just thought of a question for the old time experienced crew: would the ancient practice of 'sweetening' or 'seasoning' a freshly mixed batch of this developer with ten or twenty per cent by volume of week-old working solution be of any value? I've tried this on several occasions with other developers, and I have to admit I've never seen the benefit. TTBOMK this is a practice used for motion picture developing where they want to keep the activity of the developer constant from the last film through a tank of old developer to the first film through a tank of fresh developer. Richard Knoppow would know: "Knoppow Knows" - does that count as nominative determinism? -- Nicholas O. Lindan, Cleveland, Ohio Darkroom Automation: F-Stop Timers, Enlarging Meters http://www.darkroomautomation.com/index.htm n o lindan at ix dot netcom dot com Evidently some chemicals keep better in solution than in powder form. Ammonium thiosulfate, the basic ingredient of "rapid" fixers is one. This is why rapid fixer is sold as a liquid concentrate rather than a powder. I don't know if this is true of Glycin. I think the main reason for the long life of your working solution is that it was well protected from air in storage. Kodak gives lifetimes for some developers when used in tanks with lids as a week, the bag should be better depending on what plastic its made of. Adding some used developer to fresh can keep its performance more uniform. As developer is used it accumulates reaction products. Some of these, like Bromide and Iodide, come from the film or paper, some are from the developing agents. The reaction products are not consistent in their effects, for instance, the reaction products of Metol are restrainers but those of Hydroquinone are accelerators. In general the presence of sulfite tends to reduce the effects of these reaction products. Also, in developers containing both Metol and Hydroquinone the two tend to regenerate each other also reducing the effects of the reaction products. Although fresh developer can have Bromide added to it to act as an anti-fog restrainer the effect may not be quite the same as developer which has additional reaction products in it. The practice of adding some old developer to fresh developer is a way of trying to keep the developer more uniform in action. Motion picture practice changed over the years. In the early days most negative processing, and probably most print processing, was carried out in rack-and-tank units mostly by hand. As the volume of work became greater some processing began to be done in machines. After the introduction of photographic sound recording the requirements for processing control became very much greater than is needed for the picture alone so the use of automatic machine processing rapidly became standard practice. Also at about the same time (late 1920's) research was begun on replenishing. By about the early 1930's systems of replenisment were devised to extend the life of the developer and insure uniformity in machines. The research continued because early replenishment systems were not entirely satisfactory. I don't have numbers for the life of processing solutions in current machines but its very long. The developer and other solutions in current automatic processing machines is not only replenished by the addition of more developer but regerated by removing dissolved silver and some other chemicals. For the most part replenishment of B&W developers for home use is not too practical because the volume of use is too little. However, simple replenishment according to instructions can keep many developers going for very long periods of time (over a year). Ideally, the developer performance should be tested by sensitometric means but this is really necessary only when very critical work is being done. -- --- Richard Knoppow Los Angeles, CA, USA |
#4
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102 print developer storage as working solution
On Sep 27, 4:14 am, Lloyd Erlick wrote:
Recently I posted regarding a print developer I've been playing with lately: Edwal 102 (Potassium version). Anyway, I'm a little surprised to find a developer that keeps a week in the form of a partially used working solution. In fact, I'm amazed and wondering if this isn't too good to be true. Could this be the reason Edmund Lowe (who invented this developer) specified phosphate in the formula? Is this part of the reason it keeps well? l --le Phosphate. The TSP or your TPP has a very high ph; above by some measure that of S or P carbonate. I'm quite sure it is specified because it will speed the processing of prints. As for it's acting as an preservation agent I think that not possible. It is as fully oxidized as any carbonate. In fact do to the high ph of it's solutions it would be reasonable to expect a higher rate of oxidation. Likely the same print results could be obtained using P. carbonate with longer development times. I've tested D-23 against Ansco 120 with same print results. Ansco 120 is a carbonated metol sulfite developer while D-23 has only sulfite as activator. I do not know why Glycin behaves as it does; good wet poor dry. If I can think of something convincing I'll pass it along. Dan |
#5
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102 print developer storage as working solution
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#6
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102 print developer storage as working solution
"Lloyd Erlick" Lloyd at @the-wire. dot com wrote in message ... On Fri, 28 Sep 2007 03:57:24 -0700, wrote: Likely the same print results could be obtained using P. carbonate with longer development times. I've tested D-23 against Ansco 120 with same print results. Ansco 120 is a carbonated metol sulfite developer while D-23 has only sulfite as activator. September 28, 2007, from Lloyd Erlick, Well, that's interesting. I can omit the carbonate from my 120 developer and see no difference in prits? Hmm. There must be some catch. Lower capacity? regards, --le It may affect maximum black and will certainly affect contrast. Print developers are made active both to make them fast and because prints are developed to the maximum contrast and density the emulsion is capable of. Negative film is usually developed to a considerably lower contrast and maximum density than the emulsion is capable of. TSP is certainly more alkaline than Carbonates but I rather think its used in developers at least partly because its a sequestering agent for dissolved minerals in the water. This is what makes it an effecient cleaning agent. I have seen formulas for negative developers containing some TSP for machine processing of motion picture film so it can be used in low contrast developers. I agreew with Dan Quin that there is probably little or no effect on developer life but I am not an expert chemist so there could be some effect I've never heard of. -- --- Richard Knoppow Los Angeles, CA, USA |
#7
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102 print developer storage as working solution
On Sep 28, 2:03 pm, "Richard Knoppow" wrote:
"Lloyd Erlick" wrote Well, that's interesting. I can omit the carbonate from my 120 developer and see no difference in prits? Hmm. There must be some catch. Lower capacity? le It may affect maximum black and will certainly affect contrast. Print developers are made active to make them fast and because prints are developed to the maximum contrast and density the emulsion is capable of. Negative film is usually developed to a considerably lower contrast and maximum density than the emulsion is capable of. Max black and contrast twixt a D-23 and Ansco 120 processed print are same. My formula D-23 is 8 grams metol and 80 grams sodium sulfite, water to make 1 liter. The working strength was 1:1, volume 1/8 liter and as much as 8 minutes in the developer. The Ansco 120 was used at a 1:11 dilution, 1/8 liter, one-shot; perhaps 3 minutes. So a sulfited only metol developer will produce a same print as a carbonated metol sulfite developer. What's so unexpected of that given the amount of additional time it takes to do it? I'm not saying it's practicle. I'm only pointing out to Mr. Erlick that he could substitute potassium carbonate for the potassium phosphate. As with the sulfite powered D-23 and carbonate powered Ansco 120 he could expect identical results. And it might be practicle. All we are talking about is the activation ph; the lower the longer the processing. TSP is certainly more alkaline than Carbonates but I rather think its used in developers at least partly because its a sequestering agent for dissolved minerals in the water. This is what makes it an effecient cleaning agent. Do not confuse TSP or TPP with the metaphosphates; the Calgon type phosphates. Neither TSP or TPP poses any complexing properties. I have seen formulas for negative developers containing some TSP for machine processing of motion picture film so it can be used in low contrast developers. Film or paper, pull it soon enough and the contrast will be low. Give a film plenty of exposure and as with paper, with enough time in the developer it will produce maximum black. Many film developers make good print developers. To speed them add a little carbonate. I think Kodak's D-78 may make a good Glycin print developer. Sodium sulfite, Glycin, and Sodium carbonate; 3 and 3 and 6 grams in that order. Water to make one liter. Gotta try that myself one day. I'll leave the dilution to the reader. Dan |
#8
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102 print developer storage as working solution
On Sep 27, 4:14 am, Lloyd Erlick Lloyd at @the-wire. dot com wrote:
This actually raises an interesting "difficulty" -- Glycin does not keep well in dry powder form, and if a working strength developer solution will keep well, the length of time required to use up the supply of Glycin is extended. I bought 250 grams, which is starting to look like much too much for one time. I've heard there are ways to keep Glycin in solution form better than in powder, but I've never learned details or tried it myself. Freeze the powder. I have glycin in my freezer from 19 months ago and it looked good as new this week. |
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