Formulating a sharp solvent MQ developer

[Harold33]

To achieve a true increase of definition and/or sharpness (acutance) in a classic MQ developer, the most commonly used chemical strategies are :

1. the diminution of solvent effect by diminution of the sodium sulfite content to 75-80 gr. by liter ;
2. the use of potassium bromide to prevent discontinuities caused by borax ;
3. the replacement of hydroquinone by ascrobic acid (or sodium isoascobate) ;
4. the replacement of hydroquinone by phenidone.

Developers such as Adox MQ, Agfa 44 (Ansco 17), DuPont ND-2, are typical examples of 1-2, Kodak D-96A is an early example of 1-3, while 4 is illustrated by the family of FX developers.

But according to Crawley, there is also a lesser-known way to go in the same direction. According to him : « The buffering of borax with boric acid does not seem to improve definition, altough (…) sharpness is improved » (as quoted in Anchell & Troop’s Film Dev. Cookbook, p. 44).

As far as I know, Crawley is the only researcher who claimed that boric acid had such a property. In most textbooks, boric acid is quoted as a buffer component used to stabilize borax or to lower pH, but nothing else.
Does anyone have an opinion to share on this point ?

If Crawley’s claim is true (?), I wonder what amount of boric acid is needed (at least 2 gr. ? more ?) and what amount of supplementary borax is needed to counterbalance the pH lowering ? (for example, ID-68 use boric acid : 2 gr. + borax : 7 gr., when Adox-like developers use 4 gr. of borax only).

 

[Keith Tapscott.]

To achieve a true increase of definition and/or sharpness (acutance) in a classic MQ developer, the most commonly used chemical strategies are :

1. the diminution of solvent effect by diminution of the sodium sulfite content to 75-80 gr. by liter ;
2. the use of potassium bromide to prevent discontinuities caused by borax ;
3. the replacement of hydroquinone by ascrobic acid (or sodium isoascobate) ;
4. the replacement of hydroquinone by phenidone.

Developers such as Adox MQ, Agfa 44 (Ansco 17), DuPont ND-2, are typical examples of 1-2, Kodak D-96A is an early example of 1-3, while 4 is illustrated by the family of FX developers.

But according to Crawley, there is also a lesser-known way to go in the same direction. According to him : « The buffering of borax with boric acid does not seem to improve definition, altough (…) sharpness is improved » (as quoted in Anchell & Troop’s Film Dev. Cookbook, p. 44).

As far as I know, Crawley is the only researcher who claimed that boric acid had such a property. In most textbooks, boric acid is quoted as a buffer component used to stabilize borax or to lower pH, but nothing else.
Does anyone have an opinion to share on this point ?

If Crawley’s claim is true (?), I wonder what amount of boric acid is needed (at least 2 gr. ? more ?) and what amount of supplementary borax is needed to counterbalance the pH lowering ? (for example, ID-68 use boric acid : 2 gr. + borax : 7 gr., when Adox-like developers use 4 gr. of borax only).

The standard D-76/ID-11 formula works perfectly well and doesn't need any tinkering with. Ilford still recommend ID-11 diluted 1+3 when maximum sharpness is required in their technical publications.

Borax actually releases boric acid when it is dissolved according to this link and borax is already an effective buffer on it's own. You could try D-76d, but I much prefer the standard formula.

http://www.borax.com/detergents/pheffect.html

 

[steven_e007]

I have no expertise at all in developer formulation, although it interests me. So, just curious:


"4. the replacement of hydroquinone by phenidone".

Isn't phenidone a substitute for metol? I have read that phenidone doesn't form mackie lines so easily as metol and since edge effects give the impression of higher acutance, would an MQ developer be a better option for high acutance than PQ?

"2. the use of potassium bromide to prevent discontinuities caused by borax ;"

Please can you explain this? What are the 'discontinuities caused by borax" ?

 

[Keith Tapscott.]

Ryuji Suzuki wrote something that might interest you here about D-76, Dead Link Removed but I still don't see any point in making anything other than the standard formula.

 

[Keith Tapscott.]

I have no expertise at all in developer formulation, although it interests me. So, just curious:


"4. the replacement of hydroquinone by phenidone".

Isn't phenidone a substitute for metol? I have read that phenidone doesn't form mackie lines so easily as metol and since edge effects give the impression of higher acutance, would an MQ developer be a better option for high acutance than PQ?

"2. the use of potassium bromide to prevent discontinuities caused by borax ;"

Please can you explain this? What are the 'discontinuities caused by borax" ?

It seems that Phenidone and it's derivatives can produce a slight speed increase over metol, but also slightly coarser grain. Play around with the basic D-76/ID-11 formula with metol and another replacing metol with either 0.2 gram of phenidone or dimezone-s and see which you prefer.

 

[Keith Tapscott.]

Here is a Microphen type developer.

http://www.film-and-darkroom-user.org.uk/forum/showpost.php?p=6982&postcount=1

 

[Harold33]

"4. the replacement of hydroquinone by phenidone".

Isn't phenidone a substitute for metol? I have read that phenidone doesn't form mackie lines so easily as metol and since edge effects give the impression of higher acutance, would an MQ developer be a better option for high acutance than PQ?

You are right ! It's a misprint : Read metol for hydroquinone.

"2. the use of potassium bromide to prevent discontinuities caused by borax ;"

Please can you explain this? What are the 'discontinuities caused by borax" ?

In his famous article, Crawley explain that "in a sensitive carbonate developer the introduction of 0.1 grams per liter of borax will produce a slight sheen". With recent film, I never saw this 'sheen', but it was occasionaly visible with films like 'old' Tri-X [before 1980] souped in D-76.

 

[Alienguru]

You could search for Mytol. Thought it doesn't contain any Potassium bromide, it is said to produce low base fog.

 

[Harold33]

The standard D-76/ID-11 formula works perfectly well and doesn't need any tinkering with. Ilford still recommend ID-11 diluted 1+3 when maximum sharpness is required in their technical publications.

Of course, but my question is about chemical composition.

 

[Alan Johnson]

From Crawley, BJP Dec 16 1960:
"...as regards absolute granularity per film speed...D-76 remains unsurpassed; to some extent it wins by a foul,since the definite sheen imparted to a film by its use acts as a sort of dichroic diffusing screen during printing...D-76 gains in absolute grain refinement by losing in acutance..."
"The buffering of borax with added boric acid does not seem to improve definition,although the borax sheen is removed and sharpness improved"

It seems Crawley considered the sheen left by D-76 reduced sharpness but was removed by boric acid.

The 60's films often contained less iodide than modern films and were more prone to forming edge effects so perhaps this may not generally be true today.

 

[ruilourosa]

try Fx-1, the sharpest... and forget hidroquinone.

 

[Harold33]

try Fx-1, the sharpest... and forget hidroquinone.

and forget also mid-tone contrast !
In my opinion, MQ solvent developers are unsurpassed for the grey-scale and for the resolution of fine details (which is not the case with high-acutance developers).

 

[Gerald C Koch]

By sharpness do you mean acutance? Sharpness is rather a vague non-technical term.

Your first premise is wrong. Maximum solvency of sulfite to silver halide actually occurs at about 70 g/l not at 100 g/l as you suspect. So reducing the concentration to 70 g/l actually makes sharpness poorer.

Sharpness depends on many factors not only sulfite ion concentration. You must also consider the choice of developing agent as well as other factors. Just adding boric acid may not improve sharpness.

If you want better sharpness then use one of the many acutance developers such as the Beutler formula or an ascorbate developer such as Xtol. As it has been said many times on APUG, the creation of a new and practical developer requires a very good knowledge of chemistry and in particular photochemistry.

BTW, premises 2 and 4 make absolutely no sense.

 

[steven_e007]

Personally I have tried FX1 many times and found it disappointing.

Certainly the iodide seems, to me at least, to have no effect. I suspect that with 1950s/60s emulsions it may have done - but with something like FP4+ I personally could see no beneficial effect. (One day I intend to try it on something like Adox CHS50).

It seems to me to behave much like any other soft metol only developer such as D23.

There was a very interesting article by Micheal Maunder in the now defunct AG+ magazine. This had a lot to do with Eddie Ephraums and Martin Reed of Silverprint (UK) who is active here on APUG.
MM criticised D76 for the same reasons as Geoffrey Crawley did, that it produces a degree of fog which muddies the definition a bit.
He advocated the use of DK-50 instead. I tried this, based on his recommendation. I found, exactly as he described, that it seems to give a bit more genuine speed (a little bit), higher sharpness and acutance and a little more grain. Being into medium format this was, for me, a good trade off.
He described DK-50 negatives as 'squeaky clean' compared to D76 - which I agree with. I used it for several years, until I got bored of mixing it (couldn't buy it where I lived).

 

[Keith Tapscott.]

Personally I have tried FX1 many times and found it disappointing.

Certainly the iodide seems, to me at least, to have no effect. I suspect that with 1950s/60s emulsions it may have done - but with something like FP4+ I personally could see no beneficial effect. (One day I intend to try it on something like Adox CHS50).

It seems to me to behave much like any other soft metol only developer such as D23.

There was a very interesting article by Micheal Maunder in the now defunct AG+ magazine. This had a lot to do with Eddie Ephraums and Martin Reed of Silverprint (UK) who is active here on APUG.
MM criticised D76 for the same reasons as Geoffrey Crawley did, that it produces a degree of fog which muddies the definition a bit.
He advocated the use of DK-50 instead. I tried this, based on his recommendation. I found, exactly as he described, that it seems to give a bit more genuine speed (a little bit), higher sharpness and acutance and a little more grain. Being into medium format this was, for me, a good trade off.
He described DK-50 negatives as 'squeaky clean' compared to D76 - which I agree with. I used it for several years, until I got bored of mixing it (couldn't buy it where I lived).

I too was disappointed when I tried Beutler's and FX-1. The sharpness didn't look much, if any better than D-76 diluted 1+1 and the mid-tones looked compressed.

I have the entire series by Michael Maunders and it generally describes the use of D-76 replenished which is how he recommends D-23 to be used or else as the fore-bath in a two-bath developer. Even Geoffrey Crawley acknowledged D-76 as a good developer when used diluted.

 

[Harold33]

I too was disappointed when I tried Beutler's and FX-1. The sharpness didn't look much, if any better than D-76 diluted 1+1 and the mid-tones looked compressed.

That's exactly why I prefer to explore MQ solvent developers.
It's also true that diluted developers like DK-50 give excellent sharpness for a really nice tonal scale, but their compensating effect is weak. I my (limited) experience, a landscape under a brillant sun with deep shadows and fully illuminated zones will contain burned areas.

 

[ruilourosa]

Certainly the effect of FX-1 is more pronouced than solvent Mq dev´s. Try it with pan f, and yes FX-1 is not good for midtones, but you can´t have it all... Maybe a well diluted solvent MQ will do the trick, even best, a well diluted MQ Carbonate... (why not try the FX-55 but substituting the phenidone and ascorbate by Hidroquinone and metol??)

 

[Gerald C Koch]

I too was disappointed when I tried Beutler's and FX-1. The sharpness didn't look much,

What films did you try with the Beutler developer? Years ago I used this developer with Kodak Pan-X and got stunningly detailed negatives.

DK-50 may be used as an acutance developer when diluted 1+4 and with the sodium metaborate concentration increased. This modification provides a useful balance of acutance, gradation and speed with a controlled contrast rise.
Rate films at their normal ISO speed.

Stock Solution A

Undiluted DK-50

Stock Solution B

Distilled water (50°C) 800 ml
Kodak Balanced Alkali 80.0 g
Distilled water to make 1.0 l

Take 2 parts of Solution A, 1 part of Solution B, and 7 parts water. Use once and discard. Average development time is 8 to 13 minutes at 20°C.

The above variation of DK-50 is from the British Journal of Photography Annual 1972, p 230.

Composition of the working solution
Metol 0.5 g
Sodium sulfite (anhy) 6.0 g
Hydroquinone 0.5 g
Kodak Balanced Alkali 10.0 g
Potassium bromide 0.01 g
Distilled water to make 1.0 l

 

[Harold33]

FX-1 is not good for midtones, but you can´t have it all... Maybe a well diluted solvent MQ will do the trick, even best, a well diluted MQ Carbonate... (why not try the FX-55 but substituting the phenidone and ascorbate by Hidroquinone and metol??)

I'm looking for the best sharpness combined with the best (in my opinion) tonal scale the MQ developers can offer.

I tried to substitute the phenidone + ascorbate by by metol + ascobate using the XTol formula (in my notes, I called it MeTol):

MeTol
sodium sulfite 85
metol 2
sodium bisulfite 3,5
sodium metaborate 8
sodium isoascorbate 12

The negatives (FP4+ and HP5+) looked not bad at all, but I didn't saw a true increase in definition/sharpness.

 

[Alan Johnson]

Production of edge effects is detailed in "Controls in Black and White Photography" by R.Henry,p214 for D-76 1+1 ,p240 for Beutler,with Tri-X film.I once ran tests and found the older type films, Plus-X,Tri-X,Adox CHS 25,50,100 give the greatest edge effect.With TMX there was virtually none,which was attributed to difference in iodide content when I asked about it.Time when this type of film was popular was called by Crawley the "acutance era".The last of the Agfa APX 100 shows edge effects as well.

 

[Ryuji]

From Crawley, BJP Dec 16 1960:
"...as regards absolute granularity per film speed...D-76 remains unsurpassed; to some extent it wins by a foul,since the definite sheen imparted to a film by its use acts as a sort of dichroic diffusing screen during printing...D-76 gains in absolute grain refinement by losing in acutance..."
"The buffering of borax with added boric acid does not seem to improve definition,although the borax sheen is removed and sharpness improved"

It seems Crawley considered the sheen left by D-76 reduced sharpness but was removed by boric acid.

The 60's films often contained less iodide than modern films and were more prone to forming edge effects so perhaps this may not generally be true today.

I found a few things Crawley said that makes no sense to me in terms of chemistry. Borax and boric acid are essentially the same compound just the pH is different. In fact, borax is a mixture of half boric acid, half sodium metaborate. So, stating borax causes something, which is removed by boric acid, without stating the pH makes zero sense to me.

I’ve also made a number of emulsions, many of them very old technology like 1920s to 1950s technology, and some of them were processed in solutions using borax. No sheen.

So, I think it is safe to put this “borax sheen” story in the irrelevant category.

 

[Ryuji]

Not that I believe the goal of inventing a "sharp solvent MQ developer" has any particular value, but if you are serious in pursuing that line of ideas, you should study the additives that were used in advanced monobath formula. For example, mercaptoisobutyric acid is known to reduce granularity in developers where physical development can increase granularity, while not affecting the MTF much. Another example is 3-mercaptopropionic acid, which has similar but not as drastic reduction of granularity but also increases MTF beyond 100% compared to absence of the additive.

Another approach is development inhibitor coupler. There are a couple of compounds known to strongly inhibit development, and these compounds can be coupled with a group that reacts with oxidized developer, just like dye couplers in color material. This way, edge effect can be greatly enhanced. These were more common in color films, but similar idea could be incorporated to B&W developers.

I personally don't believe MQ is particularly a good direction to go. Phenidone-ascorbate combination offers better overall image quality. At least, by replacing hydroquinone with ascorbate, Metol developers can offer better granularity and accutance (the molarity and pH must be matched).

 

[Ryuji]

The impression of sharpness also has to do with edge effects. You need controlled exhaustion, ...

“Controlled exhaustion” is a notion relative to diffusion rate.

Developer must exhaust “faster” than the diffusion rate, by which new developing agents will arrive and byproducts removed. What that means is that, long developing time (slow development) does not help increase accutance UNLESS the agitation is reduced. In other words, if the agitation technique is held constant, for each film, there is a rate of development that gives good accutance. Depending on the film and developer, this value may or may not be within a practical range.

One virtue of Phenidone-ascorbate developers is that you can dilute and process at 25C or even 27C to produce good shadow details and good accutance without losing much on granularity. In fact, I do much of my routine processing at 24, 25 or 27C. If you do this with hydroquinone developer, you may get harsh tonality or grain.

 

[ruilourosa]

Well... Solvency has to go... and maybe metol and ascobates aren´t the way... even though i´m quite happy with some MC-TEA experiments! I agree with the fact that some emulsions respond quite negatively to metol carbonate, but i think you cannot get any sharper (try adox films...).
Another thing, if you get a bit bigger (in the negative) the midtone compression will disappear, as will the adjacency effects!!! but maybe in the medium format you could get the look you want, sometimes that sharp look you are after is a combination of factors, lens, contrast index, developer( temperture, dilution, agitation), size of the negative, printing size, printing contrast, enlarging lens,enlarger focusing and collimation, even camera technique and lighting...

I´ve read Controls in Black and White Photography, Image Clarity, The Edge of Darkness and some other things, did some testing and i believe that it´s a matter superimposed factors

 

[Harold33]

(...) So, I think it is safe to put this “borax sheen” story in the irrelevant category.

As a matter of fact, I never saw it with "modern" films (after 1980), but I have somme old Tri-X negative souped in D-76 where there is something like that (it's also true that "sheen" is not a very precise word to describe the situation).