Improved version of DS-10 by Ryuji Suzuki?

[Photo Engineer]

Sodium Sulfate is one of the best anti-swell agents for gelatin.

PE

 

[Thomas Bertilsson]

Thanks, Thomas, I am fully aware that "stand development" (I put it in quotes because agitation does take place every so often) combined with weak dilutions can reduce contrast in a neg. The important point is, though, that not all developers respond to this in the same way, I would imagine a strongly buffered developer does this much less than a poorly buffered counter part, all other things the same. Rodinal is known to work extremely well with stand development. Its other big plus is that it is very well characterised after so many decades of heavy use. There are, however, hopefully some additional ways of achieving a flatter curve in the highlights which also work with devs more suitable for e.g. Delta 3200 (I have nothing against TMZ except that it doesn't come in 120 format).

That article is not about standing development. It is about using agitation as a tool to shape the tone curve. 1m agitation intervals will cause a different tonality than 5m agitation intervals.
This works well with Rodinal, but Xtol works equally well, as does Edwal 12. (Those are the developers I have used this way, and have experience with using this technique).
Rodinal works very well at the 1+50, or 1+25 dilution too using this technique.

I posted the link, because Ryuji said it was very difficult to alter the tone curve because it was very much a characteristic of the film used. I counteracted that comment by showing that you can override the tonality of some films (TMY-2, Tri-X 400, FP4+, TMX, Acros, Delta 3200, which have long straight curves) and create a shoulder by slowing down agitation. I do it myself every single time I develop film.

 

[Rudeofus]

@PE: can you give me any details about quantities to use for the effect I want? Is the number from the dark room cookbook (105g/1l) a good starting point?

@Thomas: I understand the difference between stand developing and what you suggest in your article. Stand development is one extreme which would bend the characteristic curve a lot, frequent agitation is the opposite extreme which creates a straight(er) curve, and your suggestions cover the range in between to fine tune the outcome. I'm also surprised that Ryuji questioned the shapeability of the characteristic curve since I have read too many times that different developers yield different curves.

@Mark: you recipe worked, I developed for 12 minutes (attempted 2 stop push), agitated every 1/2 minute and got reasonable looking negatives. I'll try to print a few of them on Wednesday and will report what I find especially with regard to speed and highlights. Please note that I am aware that exposing film with the builtin meter of my Rollei 35s, pushing it two stops and then looking at the result is not the recommended way of evaluating a developer I do have a densitometer at my darkroom so if questions about my negatives arise I can take some measurements (e.g. min and max density).

 

[Photo Engineer]

You can use Sulfate at 25 - 100 g/l. The effect depends on concentration and you can salt out your developer and get crystals forming in it if you use too much. Also, the effect may be smaller than you wish.

PE

 

[Alan Johnson]

I have done some testing of PC-TEA where the developer is dilute but quite high amounts of sulfite added and I could not get grain as fine as Xtol(or DS-10,Mytol,E-76).It seems to me quite likely that the high phenidone(or derivative), ascorbate and borate in these latter contributes to the fine grain.Therefore the concentrate has to be high in phenidone,ascobate and borate.The chemistry gets to the limits of what is known,esp wrt the formation of glycol borate complexes and their dissociation,when making these concentrates.It's quite a project.

 

[Ryuji]

I posted the link, because Ryuji said it was very difficult to alter the tone curve because it was very much a characteristic of the film used. I counteracted that comment by showing that you can override the tonality of some films (TMY-2, Tri-X 400, FP4+, TMX, Acros, Delta 3200, which have long straight curves) and create a shoulder by slowing down agitation. I do it myself every single time I develop film.

Well, the sensitometric data shown at your link does show some visible difference in the curve, but if you compare that to the shoulder of Verichrome Pan or Panatomic-X (which are generally referred to as films with shoulder) or even Delta 3200 or TMZ, you are not even halfway there. I would not state that effect as if you can switch one type into another.

The best way to obtain the "shoulder effect" in film characteristics today is to use paper emulsion with toe, and use print developer that does not trim the toe.

 

[Ryuji]

I have done some testing of PC-TEA where the developer is dilute but quite high amounts of sulfite added and I could not get grain as fine as Xtol(or DS-10,Mytol,E-76).It seems to me quite likely that the high phenidone(or derivative), ascorbate and borate in these latter contributes to the fine grain.Therefore the concentrate has to be high in phenidone,ascobate and borate.The chemistry gets to the limits of what is known,esp wrt the formation of glycol borate complexes and their dissociation,when making these concentrates.It's quite a project.

Sorry, nope. The primary factor is the pH and the concentrations of the *effective* or dissociated developing agent molecules. You could use zero borate, 2g/L ascorbate, ..., 35g/L sulfite, etc., and still get good fine grain if the pH is 8.00 or 8.20 range and do not underexpose or overdevelop.

 

[Alan Johnson]

So are you saying that at a given pH increasing the phenidone & ascorbate concentrations by a factor of say,10, increases the rate at which the grains develop but has no effect at all on their size?

 

[Thomas Bertilsson]

Well, the sensitometric data shown at your link does show some visible difference in the curve, but if you compare that to the shoulder of Verichrome Pan or Panatomic-X (which are generally referred to as films with shoulder) or even Delta 3200 or TMZ, you are not even halfway there. I would not state that effect as if you can switch one type into another.

The best way to obtain the "shoulder effect" in film characteristics today is to use paper emulsion with toe, and use print developer that does not trim the toe.

It works for me, is all I can say. With my developer of choice, replenished Xtol, I use it in my own darkroom every time I process film. There are lots of things that will affect the outcome, and the reason for doing this is to be able to use the same emulsion again and again, and the real reason to do that is to be able to know exactly what to expect every time I shoot, with regard to fitting the negative to the paper.

It's one tool, among many, and my motto has been, for a long time now, that it's less important what materials we use, than HOW we use them. It helps me go into the darkroom and print with very minimal waste, both time wise and materials wise. That excites me.

 

[albada]

@Mark: you recipe worked, I developed for 12 minutes (attempted 2 stop push), agitated every 1/2 minute and got reasonable looking negatives. I'll try to print a few of them on Wednesday and will report what I find especially with regard to speed and highlights. Please note that I am aware that exposing film with the builtin meter of my Rollei 35s, pushing it two stops and then looking at the result is not the recommended way of evaluating a developer

Good to hear! Coincidentally, I just developed another test-strip with that same formula. It's drying now. This experiment tried a little pushing, but nothing as drastic as yours.

From what I'm seeing, this formula is good for pushing. It's extracting more shadow-detail than XTOL, yet without blowing out the highlights.

Mark Overton

 

[albada]

I have done some testing of PC-TEA where the developer is dilute but quite high amounts of sulfite added and I could not get grain as fine as Xtol(or DS-10,Mytol,E-76).It seems to me quite likely that the high phenidone(or derivative), ascorbate and borate in these latter contributes to the fine grain.Therefore the concentrate has to be high in phenidone,ascobate and borate.The chemistry gets to the limits of what is known,esp wrt the formation of glycol borate complexes and their dissociation,when making these concentrates.It's quite a project.

My experience agrees with Ryuji. As an example, here's a formula that gives grain matching XTOL under my 22x loupe, yet has low concentrations of phenidone and other components. This formula is for a concentrate yielding either 5 liters or 1 liter of working solution:

Working volume ----------> 5L .......... 1L
Propylene glycol .............. 75 .......... 15 ml
Sodium metaborate ......... 11 .......... 2.2 g
Ascorbic acid ................... 22.5 ....... 4.5
Phenidone ....................... 0.25 ....... 0.05 g
Propylene glycol to .......... 100 ........ 20 ml (should need to add only 5/1 ml)

pH = 8.0. Use 20ml per liter (1+49 dilution) into water containing 45 g/L sodium sulfite.
Develop for twice XTOL's times.

​

I tried this developer for the first time yesterday, and the TMY-2 test-strip looks great. The appeal is that it uses only half the sulfite as XTOL, less other chemicals, and can be concentrated to 1+49 dilution. Of course, one must develop for twice as long, but for me, that 7-minute cost more than compensates for the benefits. This formula is similar to diluting XTOL 1+1, but with less phenidone, more buffering and a lower pH to avoid the reduction in contrast. So I'm going to tweak and test this formula some more.
Anyway, it shows that low concentrations can produce grain as fine as XTOL.

My potassium sulfite and dimezone-s are here, so I need to try those out. Man, there's too much to do! Gotta stay focused...

Mark Overton

 

[albada]

PPS: Mark, some of the substances you specified come with varying amounts of H2O bound to the crystal grid. For now I assume you mean Na2BO2 * 4 H2O when you specify "Sodium metaborate". Please tell me if this is indeed the case.

The sodium metaborate I use is what PhotoFormulary.com sells, and I thought it was anhydrous. I just looked up the MSDS on PhotoFormulary's web-site (http://stores.photoformulary.com/images/store_version1/MSDS_Sodium_Metaborate_4_Mol.pdf), and it's the dihydrate version. Surprise! That MSDS says the molecular weight of NaBO2*2H2O is 101.83, instead of the 65.80 that I've been assuming all this time. Wow. Thanks for bringing this up.

That means I've been mixing some H2O into my concentrates. Not a good idea. Fortunately, I've determined the correct amount of sodium metaborate (dihydrate) experimentally in my developers, so they won't need to change. But I'll think about heating any concentrate to drive out H2O.

Mark Overton

 

[Rudeofus]

The sodium metaborate I use is what PhotoFormulary.com sells, and I thought it was anhydrous. I just looked up the MSDS on PhotoFormulary's web-site (http://stores.photoformulary.com/images/store_version1/MSDS_Sodium_Metaborate_4_Mol.pdf), and it's the dihydrate version. Surprise! That MSDS says the molecular weight of NaBO2*2H2O is 101.83, instead of the 65.80 that I've been assuming all this time. Wow. Thanks for bringing this up.

Chemistry can be a bitch sometimes I incorrectly assumed you meant the tetra hydrate NaBO2*4H2O so it looks like your recipe still yields results even if the metaborate content is off by quite a bit. Using the same weight of tetra hydrate instead of dihydrate adds only 3/4 of the metaborate to the mix.

That means I've been mixing some H2O into my concentrates. Not a good idea. Fortunately, I've determined the correct amount of sodium metaborate (dihydrate) experimentally in my developers, so they won't need to change. But I'll think about heating any concentrate to drive out H2O.

From what I have understood the main problem with water in stock solution seems to be that water dissolves oxygen which hurts the developer. If you have only trace amounts of water I can't imagine how this would hurt. The 1.2g metaborate dihydrate of your recipe contain about 0.4g = 0.4ml of water, in 30ml of propylene glycol this is a trace amount in my book.

One question for the experts: If so much Na2SO3 is added to the mix, is it necessary to add some chelating agent like Na2-EDTA (Ryuji, I don't care about long term storage now) or Dequest (if I can get this anywhere here), or is iron only a problem with color film?

One more question: I set up a stock solution of metaborate from borax and lye in water. Is this stock solution reasonably stable or does it decompose somehow? If I let all the water evaporate from this mix: can I expect sodium metaborate crystals? If yes, what amount of water can I expect in these crystals?

 

[Ryuji]

One question for the experts: If so much Na2SO3 is added to the mix, is it necessary to add some chelating agent like Na2-EDTA (Ryuji, I don't care about long term storage now) or Dequest (if I can get this anywhere here), or is iron only a problem with color film?

One more question: I set up a stock solution of metaborate from borax and lye in water. Is this stock solution reasonably stable or does it decompose somehow? If I let all the water evaporate from this mix: can I expect sodium metaborate crystals? If yes, what amount of water can I expect in these crystals?

1. why are you talking about chelating agent in relation to sulfite? They are unrelated issue. Generally speaking (not in the context of ascorbate developers) chelating agent is used so that calcium scum does not form. That is why EDTA, DTPA or NTA is usually used in packaged developers. They are not really concerned about iron. (MQ and PQ developers are not very sensitive to iron, manganese and copper impurities, where ascorbate developers are super sensitive.)

2. In ascorbate developers, dealing with trace amount of iron impurities from any possible source (including water source and sulfite stock) is crucial for reliability, not just keeping property. I would not use an ascorbate developer without this measure, even for one-shot use, period. My negatives are result of a lot of work. You should study how "sudden death of XTOL" happened. It can happen in just a matter of an hour or two, and it does not discolor the solution at all.

3. Color process is a different problem. You have a lot of iron compounds in bleach bath. In some reversal processing, they need be thoroughly removed or it will turn into stain (very problematic in print processing). But the problem is different in ascorbate developers.

4. You should really get some decent industrial chemistry references. Borate buffer is not a part of elementary chemistry but it is very common in industrial chemistry, and it is definitely important in understanding b&w film developers (as well as making your own). You should have data on concentration dependency, temperature dependency, etc. at your fingertips. Carbonate, phosphate, triethanolamine, diethanolamine, etc., are also important and useful. Those references will also have a chart on the hydration of the compound with respect to temperature and pressure.

 

[Rudeofus]

1. why are you talking about chelating agent in relation to sulfite? They are unrelated issue.
[ ... ]
They are not really concerned about iron. (MQ and PQ developers are not very sensitive to iron, manganese and copper impurities, where ascorbate developers are super sensitive.)

According to PE they are not unrelated because Na2SO3 carries iron as impurity, and you confirmed that further down in your post. If ascorbate is part of most of the formulations here and highly sensitive to iron then Mark should seriously think about adding Na-EDTA, Calgon, Dequest or whatever.

2. In ascorbate developers, dealing with trace amount of iron impurities from any possible source (including water source and sulfite stock) is crucial for reliability, not just keeping property. I would not use an ascorbate developer without this measure, even for one-shot use, period.

I referred to your quote about sudden death of Xtol and your dislike of Na-EDTA and got the impression that these are related. Since I already have Na-EDTA I would like to use it as chelating agent and think I can do this as long as I don't keep the mix for more than a day or so.

You should study how "sudden death of XTOL" happened. It can happen in just a matter of an hour or two, and it does not discolor the solution at all.

Do you mean an hour after mixing the soup or that the change from good to mostly inactive happens within this time frame? I have read up on the Xtol sudden death syndrome and the conclusion seems to be that ascorbic acid oxidizes and does this faster if iron or calcium ions are present.

Again, these issues seem very important for devs which are sold commercially and/or stored for prolonged time frames but this is not an issue for my experiments yet. "Sudden death of Xtol" is a popular topic but I don't remember it being reported for freshly mixed Xtol.

3. Color process is a different problem. You have a lot of iron compounds in bleach bath. In some reversal processing, they need be thoroughly removed or it will turn into stain (very problematic in print processing). But the problem is different in ascorbate developers.

Just for the record: stefan4u used Calgon in his working formulation of C41 color developer, which is used before the iron heavy bleach hits the film. It seems iron and/or calcium cause more trouble in color processing than just stains, so the problems may be closer related than you think. Anyway, I'm afraid I won't go out and modify Marks recipes before I get my hands on a semidecent pH meter (soon, I promise).

4. You should really get some decent industrial chemistry references. Borate buffer is not a part of elementary chemistry but it is very common in industrial chemistry, and it is definitely important in understanding b&w film developers (as well as making your own). You should have data on concentration dependency, temperature dependency, etc. at your fingertips. Carbonate, phosphate, triethanolamine, diethanolamine, etc., are also important and useful. Those references will also have a chart on the hydration of the compound with respect to temperature and pressure.

I would love to and would welcome decent references here. But first things first, as you may have read we have just established that I used only 3/4 or the metaborate that Mark recommended. It was my first run of home brew developer, luckily it yielded usable results so I am highly motivated to go on with these experiments. The darkroom cookbook will arrive tomorrow so my knowledge of photo chemistry will at least quadruple over the next few weeks

 

[analog what is that?]

One more question: I set up a stock solution of metaborate from borax and lye in water. Is this stock solution reasonably stable or does it decompose somehow? If I let all the water evaporate from this mix: can I expect sodium metaborate crystals? If yes, what amount of water can I expect in these crystals?

I'd like to highlight this and hopefully somebody with experience will answer.

 

[Ryuji]

According to PE they are not unrelated because Na2SO3 carries iron as impurity, and you confirmed that further down in your post. If ascorbate is part of most of the formulations here and highly sensitive to iron then Mark should seriously think about adding Na-EDTA, Calgon, Dequest or whatever.

I’m not supposed to comment on whatever the gentleman from upstate New York says, and he is not supposed to comment on my work or my statements, or anything related to me.

That said, you need to understand “chelating iron” does not always do the same thing in this context. It is a very delicate matter, simultaneously concerning electrochemical *and* coordination chemistry aspect of iron as redox catalyst. This issue is not very specific to ascorbate developers, and it arises in some places in industrial chemistry as well as biochemistry. But in the context of photographic processing chemistry, ascorbic developer is by far the toughest case to deal with.

I referred to your quote about sudden death of Xtol and your dislike of Na-EDTA and got the impression that these are related. Since I already have Na-EDTA I would like to use it as chelating agent and think I can do this as long as I don't keep the mix for more than a day or so.

My answer is the same. EDTA makes it worse.

Do you mean an hour after mixing the soup or that the change from good to mostly inactive happens within this time frame?

If you really study cases of sudden death of XTOL you know the answer yourself.

I have read up on the Xtol sudden death syndrome and the conclusion seems to be that ascorbic acid oxidizes and does this faster if iron or calcium ions are present.

Calcium has nothing to do with it. Iron, manganese, copper, these are the problems. And you see, XTOL has a copious amount of DTPA, which is significantly more powerful than, but of generally of the same type of chelating agent as, EDTA. If DTPA isn’t good enough, EDTA is not good at all. Neither is NTA.

Again, these issues seem very important for devs which are sold commercially and/or stored for prolonged time frames but this is not an issue for my experiments yet.

Are you ok with a developer that *may* die in an hour after mixing? I am not.

Of course, many people eat raw cookie dough and don’t get sick. Some get sick but they tell themselves that the dough was old, and never seriously consider the real known risk just because the chance isn’t that large.

"Sudden death of Xtol" is a popular topic but I don't remember it being reported for freshly mixed Xtol.

What are you talking about??
*Sudden* death of XTOL is about freshly mixed XTOL.

Just for the record: stefan4u used Calgon in his working formulation of C41 color developer, which is used before the iron heavy bleach hits the film. It seems iron and/or calcium cause more trouble in color processing than just stains, so the problems may be closer related than you think. Anyway, I'm afraid I won't go out and modify Marks recipes before I get my hands on a semidecent pH meter (soon, I promise).

There is no logical and semantic connection between each of your clauses above.

You need to understand the context of my previous comment about iron removal in color reversal print processing. The difficulty of the matter is considerably more than whatever context you are talking about Calgon. Calgon is not the first line of agent to try when you have any sort of iron related issue. It is more for calcium and magnesium.

Watch out for those books written for darkroom enthusiasts. They contain many overstatements, misleading statements, impractical suggestions, and some errors that people not familiar with the topic are not likely to find.

 

[albada]

Are you ok with a developer that *may* die in an hour after mixing?

Ryuji, please provide links to postings on apug or PN that report home-brew ascorbate developers (not XTOL) dying in an hour. I've used chems from PhotoFormula after a few hours or the next day, and they've been fine. So links to failures would be helpful.

I'd like to second Rudeofus' request for references to books on industrial chemistry. I have much to learn.

Mark Overton

 

[albada]

Chemistry can be a bitch sometimes I incorrectly assumed you meant the tetra hydrate NaBO2*4H2O so it looks like your recipe still yields results even if the metaborate content is off by quite a bit. Using the same weight of tetra hydrate instead of dihydrate adds only 3/4 of the metaborate to the mix.

Perhaps it's the same stuff. I noticed that the decahydrate that I used is also written as Na2*B2*O4*4H2O, which merely doubles everything, and might be what you have. Here's a data-sheet showing both formulas: http://www.borax.com/pdfs/dist/DataSheet.Borates.SodiumMetaborate4Mol2010.pdf

Even with only 3/4 of the metaborate, your pH is probably between 8.0 and 8.1, reducing activity a bit, so your 2-stop push might only be a 1-stop.

Have you looked at your negs closely under a loupe? How did the shadow-detail come out?

Mark Overton

 

[Rudeofus]

My answer is the same. EDTA makes it worse.

Does it make it worse because the iron bound by it is still or even more chemically active (like it is supposed to be in Ammonium-Ferric-EDTA) ? Or are there other effects I have not thought/learned about?

Calcium has nothing to do with it. Iron, manganese, copper, these are the problems. And you see, XTOL has a copious amount of DTPA, which is significantly more powerful than, but of generally of the same type of chelating agent as, EDTA. If DTPA isn’t good enough, EDTA is not good at all. Neither is NTA.

Would Dequest 2010 be better? I have a possible source for it here in Europe (Tronds knows about this).

Are you ok with a developer that *may* die in an hour after mixing? I am not.

Of course, many people eat raw cookie dough and don’t get sick. Some get sick but they tell themselves that the dough was old, and never seriously consider the real known risk just because the chance isn’t that large.

What are you talking about??
*Sudden* death of XTOL is about freshly mixed XTOL.

Ryuji, the instances I have read about were about XTol from which 5l were mixed some time before and which then went from active to inactive within an hour. I am sure the "Sudden Death of Xtol" has been discussed extensively over the many, many years Xtol has been sold commercially and I take your word that this happened to a few people right after opening the concentrate.

 

[Photo Engineer]

I have never seen a first hand account of XTOL "sudden death". I have heard of it being DOA when freshly mixed from early batches. Kodak revised the packaging to prevent this problem.

Iron sequestered by EDTA is much less active than free Iron, but it can still act as an oxidant and we see this in color bleaches that use EDTA or EDTA like compounds. Dequest OTOH, inactivates Iron so effectively that I have seen it decolorize Ferric salt solutions and deactivate bleaches.

So, I have worked with Dequest as an Iron salt deactivating chemical and have reported it at EK.

PE

 

[Alan Johnson]

My experience agrees with Ryuji. As an example, here's a formula that gives grain matching XTOL under my 22x loupe, yet has low concentrations of phenidone and other components. This formula is for a concentrate yielding either 5 liters or 1 liter of working solution:

Working volume ----------> 5L .......... 1L
Propylene glycol .............. 75 .......... 15 ml
Sodium metaborate ......... 11 .......... 2.2 g
Ascorbic acid ................... 22.5 ....... 4.5
Phenidone ....................... 0.25 ....... 0.05 g
Propylene glycol to .......... 100 ........ 20 ml (should need to add only 5/1 ml)

pH = 8.0. Use 20ml per liter (1+49 dilution) into water containing 45 g/L sodium sulfite.
Develop for twice XTOL's times.

​

Mark Overton

I made up the developer above, call it D316 after the post number.It could be made by heating to 70C in a water bath.The 45g/L sulfite I weighed out is about 4 heaped teaspoons.The measured pH was 8.1.
HP5+ was developed in D316 for 2x the Xtol 1+0 time.
HP5+ for comparison was developed Xtol 1+1.
The EI I would use for sun/shade conditions, average metering, was D316=EI 320, Xtol 1+1 = EI 400.
Attached scans are of 0.1 inch square sections of negative scanned on an Epson V700 at nominal 4800dpi, sharpened equally.

Conclusions:
Xtol 1+1 gives finer grain and slightly higher speed.
D316 wrt its concentrate composition and dilution is practical and economical, probably near optimal.
Concentrate is a good developer but cannot be made so as to give as fine grain as Xtol,though close.

 

[Rudeofus]

I have never seen a first hand account of XTOL "sudden death". I have heard of it being DOA when freshly mixed from early batches. Kodak revised the packaging to prevent this problem.

A simple web search yields quite a few reports but so does a search for "front focus" for just about any auto focus lens which could be attached to a Canon EOS body. I am confident that Kodak would have recalled and reformulated Xtol if this was a problem likely to happen to many customers of their product. What this means for us, though, is that we have to be careful with ascorbate based developers. We don't have the complete recipe for Xtol (the patent may not include improvements which have been kept as trade secrets) so we have no real insight how Kodak dealt with the potential sudden decay of ascorbate.

Iron sequestered by EDTA is much less active than free Iron, but it can still act as an oxidant and we see this in color bleaches that use EDTA or EDTA like compounds. Dequest OTOH, inactivates Iron so effectively that I have seen it decolorize Ferric salt solutions and deactivate bleaches.

Can it have any effect on B&W developer ingredients that we should be aware of? Any potential interactions with the fixer if we don't rinse well enough after dev? Does Dequest also catch other ions like calcium, manganese or copper or whatever may show up as impurity in the raw chems and bite our precious dev?

Perhaps it's the same stuff. I noticed that the decahydrate that I used is also written as Na2*B2*O4*4H2O, which merely doubles everything, and might be what you have. Here's a data-sheet showing both formulas: http://www.borax.com/pdfs/dist/DataSheet.Borates.SodiumMetaborate4Mol2010.pdf

The problem is that metaborate comes with different amounts of water so there was no way to be sure. There was a procedure for producing (there was a url link here which no longer exists) but again, no indication was given how much water is bound per molecule or how one would influence that amount. It looks like I should use (there was a url link here which no longer exists) as it seems the best option for me right now.

I will be in the dark room this wednesday and let you all know whether I got reasonable looking images out of that roll of film with scanned print samples. Judging shadow details is only marginally informative if one doesn't know the light level of these shadows.

 

[albada]

I made up the developer above, call it D316 after the post number.It could be made by heating to 70C in a water bath.The 45g/L sulfite I weighed out is about 4 heaped teaspoons.The measured pH was 8.1.
HP5+ was developed in D316 for 2x the Xtol 1+0 time.
HP5+ for comparison was developed Xtol 1+1.
The EI I would use for sun/shade conditions, average metering, was D316=EI 320, Xtol 1+1 = EI 400.
Attached scans are of 0.1 inch square sections of negative scanned on an Epson V700 at nominal 4800dpi, sharpened equally.

Conclusions:
Xtol 1+1 gives finer grain and slightly higher speed.
D316 wrt its concentrate composition and dilution is practical and economical, probably near optimal.
Concentrate is a good developer but cannot be made so as to give as fine grain as Xtol,though close.

I appreciate your doing this, as it's always good to have reviewers check one's work. Some questions:

* How do the densities of the two negatives compare? My goal was twice XTOL's dev-time, and I'm wondering how close I got for a conventional grain film.

* Could you compare grain by viewing the neg's directly with a loupe? I've found that even a dedicated film-scanner as good as my Nikon Coolscan IV ED does not reliably show grain due to focus-variation, so I trust direct viewing in a loupe or microscope more. Hmm, I guess a couple of carefully-focused extreme enlargements (projecting onto the floor?) would also clearly show the grain-difference.

* I notice that the area under the bumper is darker in the Xtol-scan, indicating a difference in black-point and/or gamma in the scans. How did you set these in your scanning software?

My goal is to get XTOL's grain in a concentrate, and I'll keep hammering at it. Feedback like this is good.

Mark Overton

 

[Photo Engineer]

Dequest has no interaction with any B&W chemical AFAIK.

PE