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

[Ian Grant]

I edited to add to my post and that's relevant.

Ian

 

[Lachlan Young]

True... Fig. 16 says that we have the low speed cubic layer under the tabular higher speed layer, sorry, I thought you were asking that. The ortho nature of the deep layer is seen in the T-Max datasheet, see the spectral sensitivity graph, in the curve labeled "1.0 greater than D-min" you see a great sensitivity drop from 600nm that is not seen in the "0.3 greater than D-min".

Before making such sweeping statements, you might want to look at the sensitivity plots for the other Tmax films - and the previous TMY. You'll discover that contra to your claims, TMY-II has much more even sensitivity at both measured densities - ie shadows and highlights won't have subtly different colour sensitivity. It would be really obvious both in the data and photographically if TMY-II was only panchromatic in the fast emulsion layer - not least because there would be a precipitous fall away to zero sensitivity at 550-575nm in the 1.0 plot.

then make a T-Max calibration with red light and you should see a graph shouldering way earlier than if making the calibration with blue light.

No, you aren't getting this: that a film may deliver a shoulder in a specific colour separation (and original TMY was often recommended against for separation because the blue filtered curve shoulders earlier), but all you are seeing is a partial snapshot of the film's suitability for making separation negs - not some 'truth' about its sensitisation.

anyway ortho or not is irrelevant for the difficulty it has developing the T-Max deep layer in the 1st development, as the important factor is the ultra low speed it sports to conserve linearity in the extreme highlights, at that overexposure level you mostly have bright light sources or glares.

I'd suggest it's rather different: DR5 may be struggling to usefully access the faster emulsion components in TMY-II, and only by significant overexposure can the silver in the film be sufficiently made available for development. To make progress you are going to have to bin all notions of it being simple to design a really good reversal first developer, and really start understanding the what and the why in that Agfa patent - you need to access all the emulsions and simultaneously develop them fully. That is pretty demanding to do - hence the HQMS-K and the PEG etc.

 

[138S]

Before making such sweeping statements, you might want to look at the sensitivity plots for the other Tmax films - and the previous TMY. You'll discover that contra to your claims, TMY-II has much more even sensitivity at both measured densities - ie shadows and highlights won't have subtly different colour sensitivity. It would be really obvious both in the data and photographically if TMY-II was only panchromatic in the fast emulsion layer - not least because there would be a precipitous fall away to zero sensitivity at 550-575nm in the 1.0 plot.

Lachlan, you look a rookie interpreting graphs (take it with humor)

See it again, difference is not in the 550-575nm, but in the 600-650nm, and this is only at 1.0D when the deep layer just starts working, if you could see the graph for 2.0D when the deep layer is working then the thing it's clear. At 1.0D you still don't see all the drop because density accumulated in the top layer still is relatively significative.

That graph is Log, so the "ortho" drop is quite substantial even for 1.0D.

I'd suggest it's rather different: DR5 may be struggling to usefully access the faster emulsion components in TMY-II, and only by significant overexposure can the silver in the film be sufficiently made available for development. To make progress you are going to have to bin all notions of it being simple to design a really good reversal first developer, and really start understanding the what and the why in that Agfa patent - you need to access all the emulsions and simultaneously develop them fully. That is pretty demanding to do - hence the HQMS-K and the PEG etc.

Still perfectioning that LFBB way, when I finish it I'll show you the results, don't discredit a new procedure before knowing how it works, man.

This time don't tell that I lack experience in something, I warn you before you go to the usual way. (Also take it with humor)

 

[Raghu Kuvempunagar]

Tmax 400 runs fine (as do both Delta 100 and 400) in the Agfa Scala process that Photostudio 13 have kept running (they got access to the formulae etc). They even allow 1-stop pushing of Tmax 400.

That's very impressive if Photostudio 13 is doing it without using a halide solvent. Is there a way to confirm that they're not using halide solvent for TMax films? @dr5chrome can do it only at EI 32-125.

 

[138S]

@dr5chrome can do it only at EI 32-125.

IMHO this is because of the extreme highlight latitude T-Max sports. We have to expose the very low speed emulsion, if not clearing highlights would require (sonner or later in the process) a too high thinning that it would damage DMax.

That's very impressive if Photostudio 13 is doing it without using a halide solvent. Is there a way to confirm that they're not using halide solvent for TMax films?

they are not prone to disclose industrial secrets at DR5 or Ps13

What is clear is that the lower the ISO the lower the solvent to clear highlights.

Our foe is halide in the highlights that is not developed in first development, Pro labs know how to optimally deal with that, IMO this is what we have to focus on. Tthe Lachlan's proposition to try high mol PEG is a good recommendation, but this may be only a component of the solution.

What DR5 or Ps13 do it has been refined by sound technicians and as 2020 those recipes are not disclosed, if we want a similar level at home we'll have to do a hard job. There are several factors we can play with, from my side I'll check the full potential of controled re-exposure before bleaching, which is easy for sheets but more complicated for rolls.

________

OP, sorry for the off-topic. We made a long excursion or even trekking beyond glycin boundary

 

[Lachlan Young]

Lachlan, you look a rookie interpreting graphs (take it with humor)

See it again, difference is not in the 550-575nm, but in the 600-650nm, and this is only at 1.0D when the deep layer just starts working, if you could see the graph for 2.0D when the deep layer is working then the thing it's clear. At 1.0D you still don't see all the drop because density accumulated in the top layer still is relatively significative.

View attachment 248380

That graph is Log, so the "ortho" drop is quite substantial even for 1.0D.




Still perfectioning that LFBB way, when I finish it I'll show you the results, don't discredit a new procedure before knowing how it works, man.

This time don't tell that I lack experience in something, I warn you before you go to the usual way. (Also take it with humor)

You posted T-Max 100. Which is well known to have very even spectral responses as a colour separation film.



This is TMY-II.
Those spectral responses line up pretty well, don't they?
Quite an engineering achievement given that dyes will adsorb differently to different grain shapes (which is likely at least part of the behaviour seen on the first T-Max 400 under a #47 filter).


You can see from these, with the boxes approximating the peaks of #47, #61 and #29 filters how both the first and second versions of T-Max 400 might behave when used for colour separations.
The problem with the shouldering in the highlights on the first T-Max 400 under a #47 is visible.

Finally, here's an actual Ortho film (tested under tungsten, mostly because it makes clear where the cut-off is).




Anything with sensitivity over 600nm is definitively panchromatic. If anything you claimed about T-max having a partially ortho emulsion was true, what do you think a red filter would do to highlight detail?

 

[138S]

Finally, here's an actual Ortho film (tested under tungsten, mostly because it makes clear where the cut-off is).

View attachment 248404

Lachlan, T-Max is not orthochromatic... the question is if the emulsion component that holds T-Max linearity at (say) +6 overexposure is ortho or not.

The TMY graphs show that: a well noticed red sensitivity drop by only 1.0D and that should increase as density grows. In the TMX case it is not noticed by 1.0D, probably because the tabular ISO is closer to the slow emulsion layer.

I don't remember much were I learned that the very slow component in the T-Max formulation was barely ortho sensitized to allow that ultra low ISO to keep linearity in the extreme highlights. But don't worry , when I can I'll make a red calibration and will know it for sure. This is the kind of things one has to check on his own.

I have a rectification, probably the cubic deep layer is not totally ortho, what is orto is an emulsion component in the deep layer that is responsible for linearity in the extreme highlights, requiring an ultra low ISO. Think that we are speaking about the emulsion component than has ISO 0.25 to 2, if you dye sensitize much the smallest crystals then you may exceed the ISO you are targeting. This is the explanation I was given several years ago.

I reiterate, I'll check that and I'll tell you.

 

[Lachlan Young]

I don't remember much were I learned that the very slow component in the T-Max formulation was barely ortho sensitized to allow that ultra low ISO to keep linearity in the extreme highlights.
...
the emulsion component than has ISO 0.25 to 2, if you dye sensitize much the smallest crystals then you may exceed the ISO you are targeting

Whoever told you that had their information back to front - dye sensitisation does increase speed, but any competent emulsion design team factors that in from the start. And BW is much less complex than colour in that regard.

If there was a truly orthochromatic emulsion in TMY-II you'd see it with an orange or red filter as it would cause tonalities from the mid-tones upwards to behave strangely and specular highlights to go wrong. It would be really obvious and people would complain.

I suspect that your informant has mashed together several bits of hearsay about random materials, agglomerated them to T-Max 400 and told you them as fact.

 

[Lachlan Young]

@earlz On the matter of HQMS, here's a patent for the synthesis of both HQMS salts.

I think '40 vol' works out to 12%, but don't quote me on that...

 

[138S]

If there was a truly orthochromatic emulsion in TMY-II you'd see it with an orange or red filter as it would cause tonalities from the mid-tones upwards to behave strangely and specular highlights to go wrong. It would be really obvious and people would complain.

No... because the ortho component only works in very high densities like those from bright light sources and glares, where light color is irrelevant. Nobody would notice if the emulsion component that is only exposed at +5 is ortho or not.

What is noticed is if linerity is conserved by +5 or +7 for glares, and this requires manufacturing and mixing a very, very low speed emulsion in the deep layer formulation.

 

[Lachlan Young]

No... because the ortho component only works in very high densities like those from bright light sources and glares, where light color is irrelevant..

Think about this for a minute: if you used a red #25 filter, it cuts everything below 575nm, if you used an ortho emulsion for the specular highlights, they won't really record at all because you have effectively placed a safelight filter in front of the lens. In fact they might appear instead as black 'blobs' in a print because there would be nothing recorded on the film. Furthermore, this problem would extend further down the tonal scale because emulsions are designed to link together in a visually continuous way without bumps at the transitions.

As I said, it would be incredibly visibly obvious from the upper midrange onwards if one emulsion component was not fully colour sensitised.

 

[138S]

Think about this for a minute: if you used a red #25 filter, it cuts everything below 575nm, if you used an ortho emulsion for the specular highlights, they won't really record at all because you have effectively placed a safelight filter in front of the lens. In fact they might appear instead as black 'blobs' in a print because there would be nothing recorded on the film. Furthermore, this problem would extend further down the tonal scale because emulsions are designed to link together in a visually continuous way without bumps at the transitions.

Well, it is what happens in fact with TMY if placing a red filter, it has a well lower sensitivity it the 600-650nm by 1.0D, and relative sensitivity should decrease more in that band by 2.0D, see again the spectral sensitivity graph.

Just for this reason a red filter has a remarkable compensating effect in the TMY highlights.

 

[grainyvision]

@earlz On the matter of HQMS, here's a patent for the synthesis of both HQMS salts.

I think '40 vol' works out to 12%, but don't quote me on that...

The synthesis looks pretty simple, but the hard part I'd assume is cleaning it up (remove excess sulfite) and drying it without oxidizing the HQMS

 

[Lachlan Young]

The synthesis looks pretty simple, but the hard part I'd assume is cleaning it up (remove excess sulfite) and drying it without oxidizing the HQMS

That's pretty much the problem - there's a thread where Ron & others tried the patent. I'm still not sure whether the patent refers to 40% concentration of the oxidant (which is very much into hazmat territory) or what is sold as '40 vol' in this country which equates to 12%. I'm actually struggling to think of a commercially available developer using HQMS-K (or S) that couldn't have the HQMS potentially formed in situ during manufacture.

 

[Rudeofus]

There was a guy here in this forum, @Nikola Dulgiarov , who went to great length to synthesize HQMS. He amassed a great library of patents and articles on that topic and did several experiments. He did get something going, but it was neither easy, nor a safe procedure to do at home.

I have Ron on record, that Formulary does not list every item they stock on their web page. It might be helpful to give them a call.

 

[Lachlan Young]

Well, it is what happens in fact with TMY if placing a red filter, it has a well lower sensitivity it the 600-650nm by 1.0D, and relative sensitivity should decrease more in that band by 2.0D, see again the spectral sensitivity graph.

Just for this reason a red filter has a remarkable compensating effect in the TMY highlights.

Uh, no.

T-Max 400 performs fine with a red filter. As does Fuji Acros. And the highlights perform perfectly normally unless you really screw up the processing with misplaced ideas about 'compensation'. This is really simple first-base stuff.

The filter factor numbers are in the data sheets, notice the difference between TX400 and TMY-II.



Added to this: Here's the spectral plot of Tri-X superimposed on TMY-II with the nm sensitivity aligned. I had to shift the Tri-X plot 0.5 log upwards to get them to line up for visual comparison. Red box is #25, green #29. You can see why a #25 might be a little faster under some conditions on TMY-II, and why a #29 is more useful on TXP320 (if you need to make separations).

 

[138S]

Uh, no.

T-Max 400 performs fine with a red filter. As does Fuji Acros. And the highlights perform perfectly normally unless you really screw up the processing with misplaced ideas about 'compensation'. This is really simple first-base stuff.

The filter factor numbers are in the data sheets, notice the difference between TX400 and TMY-II. T-Max 400's sensitivity remains high into the red, then cuts hard, Tri-X (TXP320 really, if you want to make separations with a #29) has a somewhat longer red sensitisation & cuts less hard, even if overall the red sensitivity is lower.

View attachment 248461 View attachment 248462

"Uh, no" ?

First, of course T-Max performs excellent with Red filter, the correction is the same for the shadows and for the mids, but with the Red filter the highlights get less exposed relatively, so compensated, this is perfectly told by the spectral sensitivity graph of TMX... This is what you are not understand: the effect is produced only in the highlights.


Let's see if I'm able to explain you that graph and if you are able to understand it, if you see the red band, it is less sensitive as density increases, this means that TMX has a superior highlight shouldering with red filtration:

With TMX that Red compensation is even well noticed by 1.0D, with TMY it is not seen in the 1.0D graph, but it should be well noticed by 1.6D.

Just think about this: as spectral response varies depending on density (so on exposure) what happens is that not all emulsion components in the formulation have the same sensitization.


In Practice what happens is that the effective Red Filter factor (to obtain same density than without filter) is different in the mids than in the highlights. Being the filter factor higher for the highlights what you have is a compensation effect.

 

[Lachlan Young]

There was a guy here in this forum, @Nikola Dulgiarov , who went to great length to synthesize HQMS. He amassed a great library of patents and articles on that topic and did several experiments. He did get something going, but it was neither easy, nor a safe procedure to do at home.

I have Ron on record, that Formulary does not list every item they stock on their web page. It might be helpful to give them a call.

That's essentially my understanding - that while relatively easy to synthesise in an aqueous solution with sulphite, getting the HQMS out and crystallising it are challenging/ potentiality dangerous (like many things in organic synthesis). And at that point, the commercial alternative seems like a pretty affordable option...

I think that most photo chemical suppliers should be able to get it - it seems to be in the catalogues of quite a few of the usual big multinational chemical supply companies.

 

[Lachlan Young]

Just think about this: as spectral response varies depending on density (so on exposure) what happens is that not all emulsion components in the formulation have the same sensitization.

I know how highlights and specular highlights behave on ortho film under a large variety of lighting conditions very, very well. TMY-II very obviously does not behave like that.

You are equally pretty obviously not talking from any usefully comparative experience.

If you did have the least experience & knowledge of the materials in question, you wouldn't spend so much time defending such obviously flawed claims.

 

[138S]

I know how highlights and specular highlights behave on ortho film under a large variety of lighting conditions very, very well. TMY-II very obviously does not behave like that.

You are equally pretty obviously not talking from any usefully comparative experience.

If you did have the least experience & knowledge of the materials in question, you wouldn't spend so much time defending such obviously flawed claims.

again going to personal disacreditation questioniong other's "experience & knowledge" ??? Perhaps it's you that are looking uncapable to interpret a technical graph, beyond your own "experience & knowledge". LOL, Lachlan.

Look, the TMX graph is self-explanatory and that hapens at even very modest 1.0D !!! What are you not understanding in that graph ? I made the effort to mark it in red... not enough ? Not necessary to be an Eistein to catch it...

Regarding the selective sensitizations of the different emulsion components of T-Max film... that response at quite modest 1.0D should you make suspect that you are overlooking something. I reiterate it to you, check response of the TMXY at high exposures and you'll learn something.

 

[DREW WILEY]

Both TMX100 and TMY400 can be used with deep 47B blue,29 red, and 61 green color separation filters, though only the 100 speed product allows you to develop all three for the same amount time to get matched curves provided you know how to find the sweet spot in exposure. You cannot do that with ACROS because it's orthopan, and any red filter stronger than a 25 drops you off the deep end. So it can't separate the same amount of linearity as TMax, and doesn't respond well to high gamma development either. FP4 would be a better substitute, though it has the infamous "blue bump" issue like ole Super XX - difficulty building equal gamma in the blue exposure. The biggest mistake most people make in general usage of TMax films is not trusting the long straight line down into the shadows, and overexposing it. ... But this thread was originally about glycin as a potential film developer, and my hunch is that it never caught on because this ingredient drifts in performance unless the powder is kept frozen for sake of freshness. It's currently a popular ingredient for paper development, so easy to acquire fresh and consistent, but that might not have always been the case. I haven't had time to read all the preceding posts yet, so will wisely avoid getting into any incipient war in the Pyrenees.

 

[138S]

so will wisely avoid getting into any incipient war in the Pyrenees.

Drew, you'd be wellcomed, but come with a plate armor dress The question is the TMX red sensitivity drop in the highlights datasheet shows.

 

[DREW WILEY]

Sorry to disappoint you, but if I ever do successfully invade the Pyrenees, it won't be with a matchlock rifle and saber, but just another Norma camera, probably Tmax film too. ... Otherwise, I have an awful lot of experience with TMax and various red filters, including at high altitude; but for general use I resorted to pyro dev a long time ago, so that affects highlight repro in a different manner than a formal color separation test.

 

[138S]

Come, post covid we may shot some big rocks and later we'll play a jousting )) to see who makes the most wonderful mural print !

We'll be shotting here:



You won't be the first californian here.

 

[Alan Johnson]

Re: the chemistry of development by glycin, I had a quick look at the books by LFA Mason and by Mees &James and neither cover it.
In "Basic Photo Science " by Walls & Attridge p181 it is mentioned that glycin is in the same family as metol.
In Mason "Photographic Processing Chemistry" p75 it is said that the oxidation of p-aminophenols can proceed in two one-electron steps, the first being production of semiquinononeimine.
IMO this primary developing agent metol probably produces a semiquinoneimine which can be reduced back to metol by certain secondary developing agents, ascorbate would fit the bill.
I would suggest that glycin adsorbed on the grains is similarly oxidized then reduced back by ascorbate.
In "Photography theory and practice vol 4 monochrome processing " by LP Clerc p 496 it is stated:
"Glycin is very sensitive to bromide and with alkali carbonates affords a slow working developer which gives low contrast and and has good keeping properties"
The low contrast mentioned appears very likely why Crawley added metol to glycin in his FX-2 two solution developer.
IMO, here the oxidized metol or glycin is not reduced back but reacts with sulfite to give a monosulfonate (Mason p78).
Crawley, BJP Jan27 1961 p42 says that FX-2 gives an 80% speed increase with certain films of that era.