Glycin-only developers "assumed to be one stop slower" -- Why?

[grainyvision]

While reading through the (excellent) Film Developing Cookbook, I found this line asserted in a few places. That a glycin only developer formula should always be assumed to cause the film to be one stop slower than box speed. Honestly glycin only film developers are quite rare, but regardless I've not seen any reports of this with the popular Hubl Paste, nor the less popular GSD-10, and personally haven't observed this in my own "EXG1" developer. Given the relative rarity of glycin only developers, how was this assumption reached? And can anyone attest from personal experience for it to be accurate? The only way I've seen it to be accurate is when using glycin without a carbonate level pH. With carbonate I get what seems like box speed, though I don''t have any precision measuring tools to say for sure.

 

[Rudeofus]

Even without "precision measuring tools" there is a distinct difference between "get ok images when shot at box speed" and "get box speed". Bill Troop, the main technical force behind the Film Developing Cookbook, talked to countless people at Kodak and other photographic companies, so I would mostly take his word on this. Rare and obscure photographic developers sometimes generate some interest by their very virtue of being special, but in the end we need to face the fact, that compounds like Glycin, Pyrogallol and p-Aminophenol remained obscure for a reason (Rodinal's faithful disciples notwithstanding).

 

[138S]

though I don''t have any precision measuring tools to say for sure.

Why not?


Doing it in the darkroom, you just need an Stouffer T2115 wedge, and following Behind The Zone System Book explanation for calibrations. Make contact copies of the wedge and scan the contact copies alongside the original Stouffer wedge, by comparing gray levels with Photoshop you know the densities for each patch in the contact copy. T4105 has 0.05D increments (1/6 stop incrementes)so it would be good for precicion measurements, but it reaches 2.05DMax, or use the T3110...


With only comparing the contact copies (say one developed with Xtol and the other one with Glycin) you have a good guess for he speed loss, just look at the patch that is starting to build density, for example, a difference of two patches it's just one stop.

Anyway the speed comparisson should be made at nominal CI = 0.62, so you should develop each strip to have the standard contrast before comparing speeds, so plotting the graphs is always good.

_____


With alkalinity you adjust infectious development, so you modifiy speed a bit.

 

[grainyvision]

I've ordered a wedge (have a 4x5 one, but that's a bit impractical for film) and actually received that exact book a few months back (along with the 4x5 wedge) for free, though I haven't dove into it yet. Either way it'd definitely be nice to compare developers in a more objective way, even if still judging density by eye. I'm also really interested on degrees of highlight compensation, which are very difficult to judge using standard subjects.

So this is off topic for this thread, but maybe someone has ideas and I'm not sure its worthy of its own thread. Anyway, I took the recipe for my EXG1 developer and changed things around quite a bit, aiming to create a high definition version of the developer, primarily by reducing the carbonate, halving the glycin, and adding an equal amount ascorbic acid. Roughly measured pH was 11 before developer and 10 afterwards. I assume the pH drop is due to ascorbic acid oxidation products being more acidic than ascorbic itself, when combined with the weak buffering system in place. Theory is that the ascorbic acid would create edge effects and is also known to increase speed (ie, xtol). The results are frankly great, a good reduction in grain levels but a definite increase in apparent sharpness with the addition of some minor edge effects... however, with this new formulation I did finally get the famous 1 stop of speed loss with glycin. Specifically I did tests with FP4+ and Ilford Ortho 80. The Ortho 80 came out absolutely perfect. The FP4+ appeared to just have a straight up loss of 1 stop in speed, the shadow detail that should've been there just wasn't until I over exposed it by a stop (at which point it looked great). Kind of off-topic, but what approach does one use for diagnosing why the loss in speed and what can be tried to return it back to box speed? Phenidone is an easy way out, but I'm skeptical about using phenidone due to its tendency to fog at this pH level and reputation for being difficult for maintaining sharp results and easily running away with highlights (which this developer already does to some extent, only weakly compensating). Additional carbonate for stronger buffering might work, but I fear this would lose the sharpness effect as well since the ascorbic acid products would be more easily removed in development. I've thought about just doubling up both the glycin and ascorbic acid, but unsure what the result would be really.

Interestingly, this developer also had a very peculiar effect I've not seen in any other developer. (see attached) the right most side of the picture is the film leader, ie, what was exposed to light for a very long time outside of the canister. The lefter side is what was pulled out of the canister to load it into the camera. I didn't do this in a dark room or anything, so the expected result should be either both equally black due to being very exposed, or the right side slightly more black. Instead, the right side is significantly lighter than the left side. I assume this is a strange "inverse" compensation due to the ascorbic acid reaction? Very strange and not sure what it actually means

 

[Rudeofus]

If you say "good reduction in grain levels but a definite increase in apparent sharpness", then what is your reference developer you compare this against?

If you look at the development process, there is the initiation of development, when tiny developable silver specks start building up, and there is the rapid development phase, in which silver builds up quickly. Phase 1 is governed by the reduction potential of the developer, and by the degree to which the developer adsorbs to the silver halide grain. Phase 2 depends on these same factors, and in addition on how quickly fresh developer is brought to the grain and how quickly oxidized developer is either restored or removed from the grain.

If phase 2 is much faster than phase 1, then you quickly build up contrast, while smaller developable silver specks remain mostly undeveloped, and you see this as "speed loss".

PS: People have seen better sharpness with Metol than with Phenidone. Since you want to make an acutance developer, you could try to add small amounts of Metol to your developer. In both cases you'd have to reduce pH by quite a bit.

PPS: Since you now have brought Ascorbic Acid into your developer, make sure you have read and understood most of the stuff Ryuji Suzuki has written about this topic. Study his DS-12 developer formula and try to go from there.

 

[Lachlan Young]

Rare and obscure photographic developers sometimes generate some interest by their very virtue of being special, but in the end we need to face the fact, that compounds like Glycin, Pyrogallol and p-Aminophenol remained obscure for a reason (Rodinal's faithful disciples notwithstanding).

At the risk of machine-gunning various sacred cattle, I strongly suspect that the two metol relatives ceased being of significant research interest to Kodak etc because Metol did the same job more efficiently (than p-aminophenol) and that glycin may have been found to be no more effective than slightly adjusting the amount of metol used (which may have depended on more accurate measuring techniques becoming available, or other analytical techniques). Kodak used pyrogallol for specific properties (tanning) in specialist developers into the 1990's, but I wonder if their avoidance of actual staining developers related to concerns over the longevity/ stability of what is effectively a dye image.

 

[Rudeofus]

Glycin is somewhat related to Metol and p-Aminophenol, but these three are very different animals as photographic developers. Especially Glycin with its very electronegative acetic acid group acts more like dihydroxybenzenes than like aminophenols. As soon, as it was technically and economically feasible, Kodak switched from all these three agents to Phenidone/Dimezone-S. They could have used Glycin together with Dimezone-S, but apparently saw no benefit in that. Their latest and most advanced black&white developer is the E6 first developer, which uses Dimezone-S and HQMS-K, not Glycin, Ascorbic Acid or any other forum favorites here.

While Pyrogallol seems to have a dedicated group of users, the late Ron Mowrey was very afraid of its toxicity, he called it one of the most toxic compounds found in dark rooms. I suspect, that Kodak disliked Pyrogallol for this very reason.

 

[grainyvision]

If you say "good reduction in grain levels but a definite increase in apparent sharpness", then what is your reference developer you compare this against?

If you look at the development process, there is the initiation of development, when tiny developable silver specks start building up, and there is the rapid development phase, in which silver builds up quickly. Phase 1 is governed by the reduction potential of the developer, and by the degree to which the developer adsorbs to the silver halide grain. Phase 2 depends on these same factors, and in addition on how quickly fresh developer is brought to the grain and how quickly oxidized developer is either restored or removed from the grain.

If phase 2 is much faster than phase 1, then you quickly build up contrast, while smaller developable silver specks remain mostly undeveloped, and you see this as "speed loss".

PS: People have seen better sharpness with Metol than with Phenidone. Since you want to make an acutance developer, you could try to add small amounts of Metol to your developer. In both cases you'd have to reduce pH by quite a bit.

PPS: Since you now have brought Ascorbic Acid into your developer, make sure you have read and understood most of the stuff Ryuji Suzuki has written about this topic. Study his DS-12 developer formula and try to go from there.

I used the wrong term actually, I'm looking more for "high sharpness and high definition", not just sharpness. Honestly fine grain and sharpness are not always at ends, just often. Specifically I believe the coarse grain I see in my sulfite-free EXG1 developer is primarily silver clumping rather than just the lack of solvent action.

Taking this theory of development, I believe what is happening is that ascorbic acid is primarily responsible for phase 1 in this developer, especially for highlights, while glycin is responsible for phase 2. The ascorbic acid oxidation products aren't really restored, but rather I believe get removed from the equation by the carbonate in solution. As far as I've researched, the only potential chemical that is capable of restoring ascorbic acid is an oxalate and that seems to only really be proven at an acidic or near neutral pH. I've messed with that combo a lot, but it gets confusing really quick without professional lab equipment and techniques for actually measuring if that property applies at alkaline pH. Regardless, it's not something in this formula. My theory is that the ascorbic acid products are sticking around too long, and preventing the glycin from developing the extreme highlights (ie, why the massively over exposed leader is less developed) and also preventing it from turning the just barely exposed grains into silver, hence the speed loss. It doesn't explain why FP4+ is so much different from Ortho 80 though. I'm beginning to suspect a camera shutter issue actually upon reviewing a few previous rolls of film. Reported exposure values by the camera's meter actually looks to be about 1/4 stop over exposed, but judging from my most recent slide film shot in the camera, it looks rather like its a 1/2 stop under exposed. Regardless, for my next batch I shot the FP4+ test strips in a different camera and am including a more diverse mix of film(FP4+, HP5+, Foma 100, T-Max 400)... Just stuck on what to tweak about the developer before processing.

I've studied Ryuji's developers and comments here extensively and actually just recently bought the final ingredient for making one of his especially interesting print developers using ascorbic + dimezone-s (could only find phenidone for a while, but Photographer's Formulary is finally back in stock). DS-12 is an interesting formula due to the mismatched amounts of ascorbic acid + metol, and the incredibly small amount of carbonate used in the working solution, and despite that still having a fairly fast development time. The TEA and salycylic acid I understand to primarily be there only for preserving the stock solution and chelating iron/copper and preventing the famous ascorbic acid "sudden death". I have both, but since I'm formulating this as an A+B solution with A containing no water (only TEA and polypropylene glycol), I think the salycylic acid isn't an important ingredient here. The TEA I'm primarily using for stock making purposes, but also for additional pH buffering and as a weak silver solvent which seems to behave quite differently from sulfite. TEA is also capable of weakly chelating some radicals (hydroquinone radicals specifically, unsure about ascorbic acid radicals) and neutralizing peroxides.

Also yes, metol definitely looks easier to work with than phenidone for this purpose if I'm going to add a third developing agent, but phenidone is super-additive with both glycin and ascorbic acid, while metol is only super additive with ascorbic acid.

At the risk of machine-gunning various sacred cattle, I strongly suspect that the two metol relatives ceased being of significant research interest to Kodak etc because Metol did the same job more efficiently (than p-aminophenol) and that glycin may have been found to be no more effective than slightly adjusting the amount of metol used (which may have depended on more accurate measuring techniques becoming available, or other analytical techniques). Kodak used pyrogallol for specific properties (tanning) in specialist developers into the 1990's, but I wonder if their avoidance of actual staining developers related to concerns over the longevity/ stability of what is effectively a dye image.

My biggest reason for not using the much cheaper and more popular metol is due to the hard requirement to maintain a much higher amount of sulfite in solution. Metol in this extremely low sulfite developer would behave similar to ascorbic acid, with the oxidation products slowing down development in heavily exposed areas. My EXG1 developer uses no sulfite at all, just TEA, carbonate, and glycin, and is capable of (at least what appears to be) full speed results, rodinal like grain, and reasonable devleopment times (almost always matching D-76 1+1)


Just to give what my thinking is with combining all of these ingredients:

* glycin -- only stable and easily usable developing agent in an extremely low sulfite formula. Also is somewhat solvent on its own. It is restored by sulfite and the oxidation products appear to simply be removed by alkali
* ascorbic acid -- Several things. Ascorbic acid is known in other formulas to potentially give a speed increase (especially with phenidone). It is not restored by sulfite and oxidation products are removed by alkali, but also neutralize the alkali. This dynamic pH juggling from this I believe can give an increase in edge effects, with contrast balanced by the glycin. The thought here is that higher density areas will have more of these very acidic oxidation products that prevent the glycin from developing near by, ie, edge effects.
* low carbonate -- too much carbonate will neutralize the ascorbic acid oxidation products too quickly to produce much edge effects
* very low sulfite -- minimal solvent effect and prevents the glycin from being restored too quickly
* bromide -- a near homeopathic amount is used. Unsure it has any effect, used it just because of some references in Film Developing Cookbook saying it can potentially increase sharpness to have a very small amount
* iodide -- Same Film Developing Cookbook recommendation. Shouldn't have much effect on cubic grain emulsions, but should increase sharpness and prevent clumping on traditional grain emulsions
* glycol -- should be effectively neutral in the developer, used to make the part A less viscous and so that the ascorbic acid dissolves more easily
* TEA -- Glycin and ascorbic acid solvent for part A. Also prevents pH from going too low, while not pushing the overall developer pH to the point that glycin and ascorbic acid really do much without the small amount of carbonate. (glycin will form a low contrast image at the TEA pH of ~9.5, but with a 1 stop loss of speed and very slow development)

Overall goal of this developer are these properties:
* "Forever" shelf life by using an A+B formulation (and a good way to use up excess glycin)
* Coarse grain and high sharpness, but without a perceived grain increase due to grain clumping (ie, I don't want the dissolved silver to be replated anywhere)
* High definition / minor edge effects, not intending to reach staining developer levels of edge effects, but something with an edge over something like Rodinal or my own EXG1
* Full speed and good results on modern high speed films, bonus points for being a decent developer for pushing
* Weakly compensating with good separation between highlights and midtones

If I can accomplish all of these goals it'd be awesome. The formula I tried is already pretty good at everything excluding speed (or maybe it is good, but not with faster modern films depending on what you consider FP4+ as), and I think edge effects could be further built up by reducing agitation.

Current modifications I'm considering are adding a very small amount of catochen to make it a true staining developer, without hopefully introducing all of the difficulties that come with a staining developer. (I can't find any info at all about catochen and glycin interaction, but with metol it is sub-additive). Remove the bromide, it may have a very minor speed effect. Increase the ascorbic acid and slightly increase carbonate to maybe increase edge effects and maybe get that ascorbic acid speed increase. Increase sulfite slightly to increase overall development rate by the glycin. Decrease TEA to increase edge effects due to less buffer and maybe increase sharpness due to less silver solvent, also decrease the expense of the developer. Increase carbonate to make development overall more rapid (12m for box speed ortho 80 is pretty slow)... Unsure exactly which direction to go, probably just going to make something up and see what happens

 

[grainyvision]

Glycin is somewhat related to Metol and p-Aminophenol, but these three are very different animals as photographic developers. Especially Glycin with its very electronegative acetic acid group acts more like dihydroxybenzenes than like aminophenols. As soon, as it was technically and economically feasible, Kodak switched from all these three agents to Phenidone/Dimezone-S. They could have used Glycin together with Dimezone-S, but apparently saw no benefit in that. Their latest and most advanced black&white developer is the E6 first developer, which uses Dimezone-S and HQMS-K, not Glycin, Ascorbic Acid or any other forum favorites here.

While Pyrogallol seems to have a dedicated group of users, the late Ron Mowrey was very afraid of its toxicity, he called it one of the most toxic compounds found in dark rooms. I suspect, that Kodak disliked Pyrogallol for this very reason.

Yea, both pyrogallol and pyrocathechin are things I worry about quite a bit in regards to toxicity. I have an unopened bottle of pyrocathechin for that reason specifically. More practically though, there's not been much research on how archival a stained negative is. A stained negative though, I will say, produces a different type of image than pretty much any other developer. It also is a great tool for taming the extreme contrast of microfilms.

And E-6 first developer is a very advanced formula, but it's also designed for a very different purpose than B/W film developers. The biggest differences being a very high contrast and long scale aim, very fine grain using unique solvents (ie, not just thiocyanate), designed to be used in a high temperature process, and to work on a multi-layer emulsion in a very precise way to maintain color balance. I don't think it's really worthwhile to say much can be drawn from the E-6 first developer formula that can be applied to normal B/W film developer formulation. Xtol on the other hand is likely the most advanced standard B/W film developer and uses Dimezone-S and ascorbic acid. It has a relatively small series of compromises that haven't really been approached by any other formula, ie, it's fine grain yet of good sharpness, gives a measurable speed increase, designed to be reused continually, and gives a normal contrast range with consistent results on modern films. The biggest problem with Xtol is just the unpredictable shelf life once mixed

 

[Rudeofus]

You'd be amazed to see, how well E6 first developer works on regular black&white film, if you dilute it 1+9 with tap water. Kodak could have switched their E6 FD to Dimezone-S/Ascorbate, but didn't. Ron was very clear about that. Yes, E-6 FD does several things in addition to "just develop silver halide", but none of these extra jobs specifically ask for HQMS.

PS: There are some credible reports about Xtol sudden death out there, but I have no seen such a report for people mixing Xtol with deionized water. Apparently some tap water sources overwhelm the chelating capacity of Xtol. This would not have prevented Kodak from making a Dimezone-S/Ascorbate based E6 FD. Ron claims, that Dimezone-S/HQMS based developers give much better sharpness.

 

[Rudeofus]

I used the wrong term actually, I'm looking more for "high sharpness and high definition", not just sharpness. Honestly fine grain and sharpness are not always at ends, just often. Specifically I believe the coarse grain I see in my sulfite-free EXG1 developer is primarily silver clumping rather than just the lack of solvent action

The sharpness of your developer has nothing to do with "grain clumping". You get strong edge effects, which give you the impression of high sharpness but also of high granularity. With a few grams of sulfite in your developer there is virtually no solvent action to be afraid of. BTW some solvent action is actually beneficial, because there are developable latent image specks underneath the silver halide grain surface. Sulfite may not be the best solvent to reveal them.

Taking this theory of development, I believe what is happening is that ascorbic acid is primarily responsible for phase 1 in this developer, especially for highlights, while glycin is responsible for phase 2.

I have done experiments with a print developer based on Ascorbic Acid alone. Trust me: Ascorbic Acid by itself is almost inactive even at high pH, I barely got a faint image after 20 minutes. In your specific developer there will be some development by Glycin, and after some time the Ascorbate will either restore oxidized Glycin or do some development on larger silver specks. When Ascorbate gets oxidized, it forms quite acidic products, which hinder development, that's the likely reason why you saw edge effects. If you have a decent carbonate buffer, the effect of these acidic end products is less pronounced. AFAIK there is no way to restore oxidized Ascorbate in a photographic developer.

The ascorbate will also decay through aerial oxidation within a few dozen minutes. Reduced amount of Ascorbate plus lowered pH from its oxidation products will likely reduce developer activity to the point, where highlights remain intact.

Also yes, metol definitely looks easier to work with than phenidone for this purpose if I'm going to add a third developing agent, but phenidone is super-additive with both glycin and ascorbic acid, while metol is only super additive with ascorbic acid

There is a developer based on Metol and Glycin: Crawley's FX 2. This tells me, that this combo may indeed have some merit. Note, that this developer uses just 3.5 g/l Sodium Sulfite, which is far away from any solvent action.

 

[138S]

A stained negative though, I will say, produces a different type of image than pretty much any other developer.

There has been a lot of controversy in the past about that, but today we know what happens.

With graded paper the stained negative will produce the same print, mostly. Also with hybrid.

With Variable Contrast paper it will be a difference in the highlights. The dense highlights have more proportional stain, acting as a filter that blocks blue, it blocks more in the denser spots... So highlights are printed with lower contrast helping its compression. Same effect than a film with more shoulder or a paper with longer toe like Lodima, Lupex or old AZO. Silver chloride...

There is something contradictory... some people praise the TMax linearity in the highlights and later they praise developing with pyro to end with a shouldering in the scene highlights. They forget to say that using a shouldered film or a long toe paper is similar.

No problem with TMX+pyro, it's a nice recipe, what's contradictory is praising TMAX highlight linearity and later having to use a shouldering effect.

Regarding pyro toxicity, principal hazard is when handling it in powder, it's when it can be breathed, when diluted it's about gloves, avoiding spills and proper disposal.

 

[grainyvision]

The sharpness of your developer has nothing to do with "grain clumping". You get strong edge effects, which give you the impression of high sharpness but also of high granularity. With a few grams of sulfite in your developer there is virtually no solvent action to be afraid of. BTW some solvent action is actually beneficial, because there are developable latent image specks underneath the silver halide grain surface. Sulfite may not be the best solvent to reveal them.

I have done experiments with a print developer based on Ascorbic Acid alone. Trust me: Ascorbic Acid by itself is almost inactive even at high pH, I barely got a faint image after 20 minutes. In your specific developer there will be some development by Glycin, and after some time the Ascorbate will either restore oxidized Glycin or do some development on larger silver specks. When Ascorbate gets oxidized, it forms quite acidic products, which hinder development, that's the likely reason why you saw edge effects. If you have a decent carbonate buffer, the effect of these acidic end products is less pronounced. AFAIK there is no way to restore oxidized Ascorbate in a photographic developer.

The ascorbate will also decay through aerial oxidation within a few dozen minutes. Reduced amount of Ascorbate plus lowered pH from its oxidation products will likely reduce developer activity to the point, where highlights remain intact.


There is a developer based on Metol and Glycin: Crawley's FX 2. This tells me, that this combo may indeed have some merit. Note, that this developer uses just 3.5 g/l Sodium Sulfite, which is far away from any solvent action.

I'll reply to this more fully in the morning, but you can lookup my experiments on an ortho litho microfilm with "PFS-4". It was simply a dilute mixture of TEA and bromide that significantly increased the speed and altered the contrast (lees runaway highlights) of this specific film. Both components I tested individually and they separately produced no noticeable effect. The same effect was not seen on HP5+, and it actually seemed to reduce the speed in a paper test while also reducing highlight density. There is some merit that TEA could be an undervalued developer component and it is capable of getting those buried grains that only highly solvent (ie with sulfite) developers can but without the typical solvent effects on grain or sharpness.. but that's still a bit of a long shot. I hadn't read FX-2's formula, but that is actually very interesting. Will definitely study it more

 

[Rudeofus]

You mixture of TEA, iodide and bromide did not increase absolute film speed, it just gave you better film speed than some of your solvent free developers alone would have given you. TEA is a silver solvent, which easily dissolves Silver Chloride in water. This prebath breaks up some grains and reveals inner latent image centers, and it probably does this to a different degree depending on grain size and composition.

Crawley's FX 2 formula is discussed in the Film Development Cookbook.

 

[mohmad khatab]

The sharpness of your developer has nothing to do with "grain clumping". You get strong edge effects, which give you the impression of high sharpness but also of high granularity. With a few grams of sulfite in your developer there is virtually no solvent action to be afraid of. BTW some solvent action is actually beneficial, because there are developable latent image specks underneath the silver halide grain surface. Sulfite may not be the best solvent to reveal them.

I have done experiments with a print developer based on Ascorbic Acid alone. Trust me: Ascorbic Acid by itself is almost inactive even at high pH, I barely got a faint image after 20 minutes. In your specific developer there will be some development by Glycin, and after some time the Ascorbate will either restore oxidized Glycin or do some development on larger silver specks. When Ascorbate gets oxidized, it forms quite acidic products, which hinder development, that's the likely reason why you saw edge effects. If you have a decent carbonate buffer, the effect of these acidic end products is less pronounced. AFAIK there is no way to restore oxidized Ascorbate in a photographic developer.

The ascorbate will also decay through aerial oxidation within a few dozen minutes. Reduced amount of Ascorbate plus lowered pH from its oxidation products will likely reduce developer activity to the point, where highlights remain intact.


There is a developer based on Metol and Glycin: Crawley's FX 2. This tells me, that this combo may indeed have some merit. Note, that this developer uses just 3.5 g/l Sodium Sulfite, which is far away from any solvent action.

This is a very nice discussion ,,
This discussion makes me feel bad, stupid, stupid and ignorant.
But it's okay
Sure I benefited a lot, but my English probably didn't help me understand all of the ideas so I think I have to use the electronic translator and re-read it several times in order to study and understand this wonderful discussion.
thank you all ,,
God bless you all .
Greetings to you from the kidnapped Egypt.

 

[Raghu Kuvempunagar]

TEA is a silver solvent, which easily dissolves Silver Chloride in water. This prebath breaks up some grains and reveals inner latent image centers, and it probably does this to a different degree depending on grain size and composition.

Would this prebath be helpful in clearing the highlights in reversal processing though it seems to have not been discussed in that context anywhere? Especially for films that don't do well in first developers containing thiocyanate/thiosulphate.

 

[Rudeofus]

I keep reading this theory about cleared highlights, but so far see no base for this in reality. An additional solvent added to a developer does several things:

1. It generally increases developer activity. The developer builds up contrast faster.
2. This increased activity can also in some cases lead to fog.
   
3. It reveals internal latent image centers, which in some cases can mean slightly higher film sensitivity.
4. It shifts the balance from chemical to physical development, which means thicker filaments. More silver has to be developed to build up density, this is seen as lower granularity. Since this effect is more pronounced around smaller latent image centers, some speed loss can go with it.

The effect most likely leading to "cleared highlights" would be the increased contrast, and I don't think, that a prebath can be of much help here. Anything affecting fog or sensitivity mostly affects the darker regions of the slides, not the highlights.

 

[bnxvs]

I used the wrong term actually, I'm looking more for "high sharpness and high definition", not just sharpness. Honestly fine grain and sharpness are not always at ends, just often. Specifically I believe the coarse grain I see in my sulfite-free EXG1 developer is primarily silver clumping rather than just the lack of solvent action.

Taking this theory of development, I believe what is happening is that ascorbic acid is primarily responsible for phase 1 in this developer, especially for highlights, while glycin is responsible for phase 2. The ascorbic acid oxidation products aren't really restored, but rather I believe get removed from the equation by the carbonate in solution. As far as I've researched, the only potential chemical that is capable of restoring ascorbic acid is an oxalate and that seems to only really be proven at an acidic or near neutral pH. I've messed with that combo a lot, but it gets confusing really quick without professional lab equipment and techniques for actually measuring if that property applies at alkaline pH. Regardless, it's not something in this formula. My theory is that the ascorbic acid products are sticking around too long, and preventing the glycin from developing the extreme highlights (ie, why the massively over exposed leader is less developed) and also preventing it from turning the just barely exposed grains into silver, hence the speed loss. It doesn't explain why FP4+ is so much different from Ortho 80 though. I'm beginning to suspect a camera shutter issue actually upon reviewing a few previous rolls of film. Reported exposure values by the camera's meter actually looks to be about 1/4 stop over exposed, but judging from my most recent slide film shot in the camera, it looks rather like its a 1/2 stop under exposed. Regardless, for my next batch I shot the FP4+ test strips in a different camera and am including a more diverse mix of film(FP4+, HP5+, Foma 100, T-Max 400)... Just stuck on what to tweak about the developer before processing.

I've studied Ryuji's developers and comments here extensively and actually just recently bought the final ingredient for making one of his especially interesting print developers using ascorbic + dimezone-s (could only find phenidone for a while, but Photographer's Formulary is finally back in stock). DS-12 is an interesting formula due to the mismatched amounts of ascorbic acid + metol, and the incredibly small amount of carbonate used in the working solution, and despite that still having a fairly fast development time. The TEA and salycylic acid I understand to primarily be there only for preserving the stock solution and chelating iron/copper and preventing the famous ascorbic acid "sudden death". I have both, but since I'm formulating this as an A+B solution with A containing no water (only TEA and polypropylene glycol), I think the salycylic acid isn't an important ingredient here. The TEA I'm primarily using for stock making purposes, but also for additional pH buffering and as a weak silver solvent which seems to behave quite differently from sulfite. TEA is also capable of weakly chelating some radicals (hydroquinone radicals specifically, unsure about ascorbic acid radicals) and neutralizing peroxides.

Also yes, metol definitely looks easier to work with than phenidone for this purpose if I'm going to add a third developing agent, but phenidone is super-additive with both glycin and ascorbic acid, while metol is only super additive with ascorbic acid.



My biggest reason for not using the much cheaper and more popular metol is due to the hard requirement to maintain a much higher amount of sulfite in solution. Metol in this extremely low sulfite developer would behave similar to ascorbic acid, with the oxidation products slowing down development in heavily exposed areas. My EXG1 developer uses no sulfite at all, just TEA, carbonate, and glycin, and is capable of (at least what appears to be) full speed results, rodinal like grain, and reasonable devleopment times (almost always matching D-76 1+1)


Just to give what my thinking is with combining all of these ingredients:

* glycin -- only stable and easily usable developing agent in an extremely low sulfite formula. Also is somewhat solvent on its own. It is restored by sulfite and the oxidation products appear to simply be removed by alkali
* ascorbic acid -- Several things. Ascorbic acid is known in other formulas to potentially give a speed increase (especially with phenidone). It is not restored by sulfite and oxidation products are removed by alkali, but also neutralize the alkali. This dynamic pH juggling from this I believe can give an increase in edge effects, with contrast balanced by the glycin. The thought here is that higher density areas will have more of these very acidic oxidation products that prevent the glycin from developing near by, ie, edge effects.
* low carbonate -- too much carbonate will neutralize the ascorbic acid oxidation products too quickly to produce much edge effects
* very low sulfite -- minimal solvent effect and prevents the glycin from being restored too quickly
* bromide -- a near homeopathic amount is used. Unsure it has any effect, used it just because of some references in Film Developing Cookbook saying it can potentially increase sharpness to have a very small amount
* iodide -- Same Film Developing Cookbook recommendation. Shouldn't have much effect on cubic grain emulsions, but should increase sharpness and prevent clumping on traditional grain emulsions
* glycol -- should be effectively neutral in the developer, used to make the part A less viscous and so that the ascorbic acid dissolves more easily
* TEA -- Glycin and ascorbic acid solvent for part A. Also prevents pH from going too low, while not pushing the overall developer pH to the point that glycin and ascorbic acid really do much without the small amount of carbonate. (glycin will form a low contrast image at the TEA pH of ~9.5, but with a 1 stop loss of speed and very slow development)

Overall goal of this developer are these properties:
* "Forever" shelf life by using an A+B formulation (and a good way to use up excess glycin)
* Coarse grain and high sharpness, but without a perceived grain increase due to grain clumping (ie, I don't want the dissolved silver to be replated anywhere)
* High definition / minor edge effects, not intending to reach staining developer levels of edge effects, but something with an edge over something like Rodinal or my own EXG1
* Full speed and good results on modern high speed films, bonus points for being a decent developer for pushing
* Weakly compensating with good separation between highlights and midtones

If I can accomplish all of these goals it'd be awesome. The formula I tried is already pretty good at everything excluding speed (or maybe it is good, but not with faster modern films depending on what you consider FP4+ as), and I think edge effects could be further built up by reducing agitation.

Current modifications I'm considering are adding a very small amount of catochen to make it a true staining developer, without hopefully introducing all of the difficulties that come with a staining developer. (I can't find any info at all about catochen and glycin interaction, but with metol it is sub-additive). Remove the bromide, it may have a very minor speed effect. Increase the ascorbic acid and slightly increase carbonate to maybe increase edge effects and maybe get that ascorbic acid speed increase. Increase sulfite slightly to increase overall development rate by the glycin. Decrease TEA to increase edge effects due to less buffer and maybe increase sharpness due to less silver solvent, also decrease the expense of the developer. Increase carbonate to make development overall more rapid (12m for box speed ortho 80 is pretty slow)... Unsure exactly which direction to go, probably just going to make something up and see what happens

What does mean "catochen"? Is it catechol?

 

[Bill Burk]

Cleared highlights... I read that the other day when I was trying out some Benzotriazole.

I could be wrong but if you are talking about negatives, then it’s to reduce fog. If you’re talking about prints ... reducing fog is the same as keeping highlights clear.

So I think that’s what the literature means by keeping highlights clear.... positives

 

[Bill Burk]

As for losing speed... Benzotriazole gives that to you... I got P3200 down to EI 250 even with a slight degree of development above ASA parameters

 

[grainyvision]

You mixture of TEA, iodide and bromide did not increase absolute film speed, it just gave you better film speed than some of your solvent free developers alone would have given you. TEA is a silver solvent, which easily dissolves Silver Chloride in water. This prebath breaks up some grains and reveals inner latent image centers, and it probably does this to a different degree depending on grain size and composition.

Crawley's FX 2 formula is discussed in the Film Development Cookbook.

I definitely don't doubt that it's not a "true" increase in speed and rather some interaction with this unique emulsion, but it gave speeds that were impossible to get in any other method excluding pre/post-flashing and interestingly, could be taken really overboard and give significant amounts of fog. I once tested the solvent effect by doing a pre-bath in a sulfite solution and also didn't see the same "effective" speed increase. The method by which PFS-4 works remains a complete mystery for me, but definitely has to do with the amine solvent effect. DEA/MEA (as in lesser "yellow" grade of TEA) promotes this effect even further and is part of it. In tests of PFS-4 made with technical grade TEA (ie, with DEA+MEA contaminates) and better photo grade TEA (clear, 99% TEA according to datasheet), I was able to still see the speed increase, but the tendency of fogging went away and the technical grade concoction could reveal about a 1/2 stop more shadow detail that would otherwise just be dmin. (these tests I actually did with a step wedge under an enlarger since 4x5 ortho litho film is super cheap and can be handled under safelight). Other ortho litho films such as Kodalith did not give the same speed increasing behavior in these precision tests, but instead had some removal of highlight density and additional "smoothness" in how shadow density built up. Shadow density increased faster than control tests rather than maintaining that steep toe that litho film is known for. No additional shadow density (ie, didn't go from dmin to some density) was revealed though. Either way, because I've never been able to successfully apply such concepts to any other film, I take anything learned in that process with a grain of salt when applying it to normal film. Also of note is that the prebath components added to the developer did not increase speed (toe density remained extremely steep), though it's hard to build a proper control test for that since TEA can have a number of different developer effects and bromide further complicates things. (also note, TEA+bromide is the key components, iodide was added because it seemed to reduce fog tendency, but unsure it is important)

I keep reading this theory about cleared highlights, but so far see no base for this in reality. An additional solvent added to a developer does several things:

1. It generally increases developer activity. The developer builds up contrast faster.
2. This increased activity can also in some cases lead to fog.
   
3. It reveals internal latent image centers, which in some cases can mean slightly higher film sensitivity.
4. It shifts the balance from chemical to physical development, which means thicker filaments. More silver has to be developed to build up density, this is seen as lower granularity. Since this effect is more pronounced around smaller latent image centers, some speed loss can go with it.

The effect most likely leading to "cleared highlights" would be the increased contrast, and I don't think, that a prebath can be of much help here. Anything affecting fog or sensitivity mostly affects the darker regions of the slides, not the highlights.

Would this prebath be helpful in clearing the highlights in reversal processing though it seems to have not been discussed in that context anywhere? Especially for films that don't do well in first developers containing thiocyanate/thiosulphate.

One of the interesting things about amines is that they are often used in color developers (even without a formula you can smell them!), but I've never seen an actual explanation for why. My suspicion is for the silver solvent effect and the relatively small amount of sulfite that can be used in color developers otherwise. Thiocyanate appears to work quite differently. My major experience with thiocyanate is in trying to figure out a reasonable RA-4 reversal first developer (no, I never cracked that puzzle, but learned a lot). (talking in negative terms, density = exposure) Even very small amounts of thiocyanate had significant increases in highlight "edge" development. ie, with a dark tree against an over exposed sky, the thin limbs would get etched away. Chloride is another interesting solvent but works by instead seeming to remove the shadow silver density while leaving highlights pretty much untouched, though of course is known to create a fine grain effect. In experiments with lith developers chloride also shifts the highlight density in positive prints from a darker pink or brown to a brighter yellow, indicating significantly finer grain structure. TEA has minimal effect in lith developers on grain color like that but has other effects. A large amount of TEA also has an interesting effect with sulfite-free hydroquinone solutions. Normally a hydroquinone solution at alkaline pH would be completely dead in 2 hours or so, but with the TEA it actually stopped with the "infectious development" type activity and remained active as a fairly fast and normal contrast paper developer after ~12 hours. I think TEA is a much more complex developer ingredient than most people would think. There are many patent references to unique action by amines, but it's hard to figure out how to actually take that specialized knowledge to apply it in a more general purpose way.

Cleared highlights... I read that the other day when I was trying out some Benzotriazole.

I could be wrong but if you are talking about negatives, then it’s to reduce fog. If you’re talking about prints ... reducing fog is the same as keeping highlights clear.

So I think that’s what the literature means by keeping highlights clear.... positives

That is definitely the case with every experiment I've done with benzotriazole. Bromide too, but to a lesser extent. With lith developer formulation specifically, there's some interesting paper I read recently that bromide in a lith developer (ie, low sulfite, hydroquinone only) actually prevents lesser exposed grains from being developed, even if moving the film/paper from the high bromide lith developer to a normal low bromide developer after 3 minutes. Doing research like this is a constant reminder that even in today's modern age with all of the scientific tools we have, there is still a lot to be learned about how silver halide photography and development really works.

And yes, I meant "catechol". My spelling of chemical names is terrible.


Anyway, to the topic at hand. I actually think that FX-2 might be related to my use of ascorbic acid. I think that 3g/L of sulfite is not enough to efficiently regenerate metol and so the behavior of that is likely related to how ascorbic acid works, but with the additional effect on localized pH that ascorbic acid products would bring. I'm still studying and trying to search out notes for why it was formulated in this way and especially how it remains such a rapid developer despite being so dilute in terms of developing agents and carbonate levels. If anyone has any clues there, I'd definitely appreciate it. Film developing cookbook doesn't go into too much detail about it

 

[Lachlan Young]

Glycin is somewhat related to Metol and p-Aminophenol, but these three are very different animals as photographic developers. Especially Glycin with its very electronegative acetic acid group acts more like dihydroxybenzenes than like aminophenols. As soon, as it was technically and economically feasible, Kodak switched from all these three agents to Phenidone/Dimezone-S. They could have used Glycin together with Dimezone-S, but apparently saw no benefit in that. Their latest and most advanced black&white developer is the E6 first developer, which uses Dimezone-S and HQMS-K, not Glycin, Ascorbic Acid or any other forum favorites here.

While Pyrogallol seems to have a dedicated group of users, the late Ron Mowrey was very afraid of its toxicity, he called it one of the most toxic compounds found in dark rooms. I suspect, that Kodak disliked Pyrogallol for this very reason.

Ah, that would explain the correlation I was finding of a drop-off in patents disclosing Glycin in formulae from about the time of the commercial introduction of Phenidone onwards. I was almost certain it had to do with Phenidone/ Dimezone S arriving on the scene, but I couldn't work out the 'why'. Mention of HQMS-K (and BW reversal) brings up this rather interesting patent which suggests that by the mid-90s Agfa and (on the basis of the TMax reversal kit MSDS) Kodak seem to have stepped away from KSCN or similar solvents in the FD in favour of specified molecular weight PEG and HQMS (or some sort of in situ synthesis in the 'commercial' MQ version - I think). I recall that Spur and Moersch are rather keen on HQMS too, though at least one Moersch formula appears to use HQMS-K and Glycin...

Mention of FX-2 has reminded me that some recent digging around in some papers about DQE (Detective Quantum Efficiency) and similar work on film information capacity from the late 70's brought up a number of citations to the effect that D-76 at 1+4 was apparently 'well known to be able to produce adjacency effects' - at least seemingly in the academic and research communities in a city in upstate NY on the shores of Lake Ontario. What this has now making me wonder is whether taking Haist's D-76 variant and modifying its stock solution to either the 20g/l Borax or 2g/l Metaborate of D-76K or DK-76 (respectively) might have useful effects when run at 1+4 - especially as in the contemporaneous late 30's literature that accompanied these variants, they were supposed to half or quarter (respectively) the development time of regular D-76 stock solution. On the other hand, DQE and similar work likely showed that the granularity/ speed/ sharpness relationship was more usefully exploitable/ expandable at the emulsion design stage than in any developer concoction.

Anyway, currently I'm looking for a tanning developer that doesn't need pyrogallol as a major ingrediant, oxalic acid as an oxidising agent (to get the tanning effect to work) or alternatively requires me to use dichromates for subsequent cross-linking effects to harden gelatin prior to hot water wash-off...

 

[grainyvision]

Ah, that would explain the correlation I was finding of a drop-off in patents disclosing Glycin in formulae from about the time of the commercial introduction of Phenidone onwards. I was almost certain it had to do with Phenidone/ Dimezone S arriving on the scene, but I couldn't work out the 'why'. Mention of HQMS-K (and BW reversal) brings up this rather interesting patent which suggests that by the mid-90s Agfa and (on the basis of the TMax reversal kit MSDS) Kodak seem to have stepped away from KSCN or similar solvents in the FD in favour of specified molecular weight PEG and HQMS (or some sort of in situ synthesis in the 'commercial' MQ version - I think). I recall that Spur and Moersch are rather keen on HQMS too, though at least one Moersch formula appears to use HQMS-K and Glycin...

Mention of FX-2 has reminded me that some recent digging around in some papers about DQE (Detective Quantum Efficiency) and similar work on film information capacity from the late 70's brought up a number of citations to the effect that D-76 at 1+4 was apparently 'well known to be able to produce adjacency effects' - at least seemingly in the academic and research communities in a city in upstate NY on the shores of Lake Ontario. What this has now making me wonder is whether taking Haist's D-76 variant and modifying its stock solution to either the 20g/l Borax or 2g/l Metaborate of D-76K or DK-76 (respectively) might have useful effects when run at 1+4 - especially as in the contemporaneous late 30's literature that accompanied these variants, they were supposed to half or quarter (respectively) the development time of regular D-76 stock solution. On the other hand, DQE and similar work likely showed that the granularity/ speed/ sharpness relationship was more usefully exploitable/ expandable at the emulsion design stage than in any developer concoction.

Anyway, currently I'm looking for a tanning developer that doesn't need pyrogallol as a major ingrediant, oxalic acid as an oxidising agent (to get the tanning effect to work) or alternatively requires me to use dichromates for subsequent cross-linking effects to harden gelatin prior to hot water wash-off...

I really wish that there was a reasonably accessible source of HQMS for home users. I've only seen insufficient purity grades, or very expensive prices of HQMS. I'm surprised that Photographer's Formulary doesn't stock it. It must be relatively complex to manufacture, otherwise I assume they'd make their own like with Glycin. HQMS seems to be the big missing piece for taming some of the problems inherit with how phenidone regeneration works that causes runaway highlights and poor sharpness. HQMS is also much more stable than standard HQMS, enabling more flexible formulations

There's a lot of problems with it but in theory hydroquinone is a staining developer. I recall seeing a thread about it somewhere here, the stain color tends to be more toward yellow. The biggest problem is that you need to prevent infectious development when considering this for normal contrast development. Also, unsure why the aversion to oxalic acid. It's fairly non-toxic (not something you want to eat, but a common thing in many vegetables etc) and easily available. I've read some document or post somewhere stating that you can actually intensify any type of staining developer (including weaker ones) by doing a quick bath of ferricyanide after development, since ferricyanide is a very strong oxidizer. Of course, you have to avoid bleaching out the shadows though and deal with the overall loss of silver density.

 

[Lachlan Young]

@earlz - in Europe, Suvatlar sells HQMS - elsewhere, I'm not so sure.

It's #95 on Suvatlar's list - maybe worth contacting him & seeing if he knows a source stateside?

As for Oxalic acid, it requires licencing to buy or use over here because of what various idiots have seemingly used it for in order to harm people.

 

[grainyvision]

@earlz - in Europe, Suvatlar sells HQMS - elsewhere, I'm not so sure.

It's #95 on Suvatlar's list - maybe worth contacting him & seeing if he knows a source stateside?

As for Oxalic acid, it requires licencing to buy or use over here because of what various idiots have seemingly used it for in order to harm people.

Very interesting, I'll have to contact them and see if it is shippable. I know there's quite a number of threads here even asking about synthesis of it due to how poorly available it is.

Surprising for sure about Oxalic acid being restricted anywhere. Here it's sold as a cleaning agent, in addition to all of the various lab uses. If you can get other strong acids (probably even more difficult?) you could in theory convert an oxalate salt to oxalic acid, but that's a whole other mess because of the various contaminates that would need to be cleaned up. Honestly though I've not heard of oxalic acid nor oxalates being used in developer aside from some very old ferrous sulfate based formulas and Pt/Pd printing