Fine Grain Development

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I have an old, but still very wonderful, book on Astrophotography. In it there is an extensive section on photographic science, including an interesting section on fine grain development. Let me precis a couple of sentences from it -

There are at least 4 ways of achieing fine grain - 1)develop to a low value of Gamma, either by diluting the developer or reducing dev time. This results in a serious reduction of emulsion speed. 2) Physical development whereby the sensitised halide grains are coated with metallic silver from the developer. Reduces the films EI 3) Use of solvents in the developer, which eats away the outer regions of the halide grains as development proceeds. Since some grains a disolved before development occurs, there is some reduction in EI. 4)The use of p-phenylenediamine as the developing agent. No developing agent produces such fine grain, but it is far more toxic than other compounds.

I found this all quite interesting. Method 2 I have never heard of before, and dont quite think I understand it as it was written. But the other three points lead me to ask 3 questions :

Method 3 is of course part of virtually every dev. formula. We see it in the form of Sodium Sulphite. This chemical acts as a preservative, but also as a solvent. I dont recall seeing any dev formulas that do not have enough Sod Sulphite not to act as a solvent. Has anyone experimented with developers which do not have Sod Sulphite? This would require either that the developer be used shortly after mixing, or that other preservatives be used in its place.

Is it possible to take a 'high contrast' developer (I dont quite know enough about this term, but perhaps dev D-8 is an example) and then 'underdevelop' to give normal contrast with finer grain? I suspect that the grain wouldnt be that fine in this case. Has anyone tried this?

Finally (whew!), p-phenylenediamine. A page at www.unblinkingeye.com mentions that it is rarely used, which certainly seems to be the case, but it appears to be in Tetenal Emofin (read the contents of the packet), and I think in D-12 (although I have never seen the formulas for either of these developers). Has anyone use this chemical and what do they think of it. Are these published dev formulas that incorporate it?

Thanks, I know this has been a long one!

George

-- George Paltoglou (stellar@optusnet.com.au), May 07, 2001

Answers

It seems to me there is a fifth possibility--use a very fine-grain film such as Technical Pan, which was originally intended for astrophotography.

There are plenty of formulas that do not use sodium sulphite (PMK, Pyrocat-HD, and Rodinal come to mind immediately). I know I have some old formularies that have formulas containing p-phenylenediamine-- when I get home this evening I will look a couple up and forward them to you, if you like. Photographer's Formulary sells the chemical.

-- Ed Buffaloe (edb@unblinkingeye.com), May 07, 2001.


Defender 5D - also known as - Dupont ND-3
Water (125° F) 750 cc
Sodium Sulfite, dessicated 90 g
Paraphenylene Diamine (base) 10 g
Glycin 2 g
Cold water to make 1 liter
Use undiluted with intermittent agitation.

Gevaert Fine Grain Formula
Distilled water (125° F) 750 cc
Metol 7 g
Sodium Sulfite, anhydrous 70 g
Paraphenylene Diamine 7 g
Glycin 7 g
Distilled cold water to make 1 liter
Use undiluted at 65° F

Sease No. 3
Water (125° F) 750 cc
Paraphenylene Diamine 10 g
Glycin 6 g
Sodium Sulfite, anhydrous 90 g
Cold water to make 1 liter
Developing time: 25 min. at 70° F.

These are all from a 1940 formulary, so I can't guarantee how they will work with contemporary emulsions.

-- Ed Buffaloe (edb@unblinkingeye.com), May 07, 2001.


George, All the papers on photo chemistry state that sodium sulfite at low concentration will just act as preservative or anti-oxidant. It means 2,0% or so. D-76, for instance, asks for 10%. That's why it's known as a fine-grain developer, but as you may easily find looking around, it will not "eat" your ISO ratings a bit! So, there seems to be some ways to overcome it's solvent action. The suggestion of trying fine-grained films really seems to be the best, since reducing grain size by chemical means may compromise resolution and some other structural habilities of any emulsion. Get a tripod and go ahead.

Cesar B.

-- Cesar Barreto (cesarb@infolink.com.br), May 07, 2001.


Just by chance, today I came across a book - The Black and White Handbook by Hicks and Shultz - that discusses those 4 approaches for fine grain in reasonable detail. Well, now I understand 'physical development' and it is definitely not on my list of things to try!

I was to hasty in my opinions about Sod Sulphite. Indeed its not in rodinal, and going through the literature I see that smaller amounts are in acutance dev like fx-1 and fx-2. So, small quantities have only a minor effect on grain size and speed, and its effect is more as a preservative. Those percentages are useful numbers. Thanks Cesar.

My concern about sod sulphite was that as a solvent, while reducing grain size, will consequently reduce sharpness thru that very solvent action. I wonder if there are formulas for super fine grain that dont use a solvent and therefore dont reduce sharpness. But, its true, why fight the inherent characteristics of the film. If you want fine grain, use a slower film and a tripod.

George

-- George Paltoglou (stellar@optusnet.com.au), May 08, 2001.


Your point about using a slower film is correct. A developer like Microdol X is a fine grain developer but so is Diafine. The difference is visual. Diafine negs. will have a tendency to "look" sharper because it is a high acutance developer which means that it will sharpen the edge effects of the grain. A high Sodium Sulfite developer will definitely mush the grain... D23 comes to mind here with it's LARGE amounts of Sulfites but for large format shooters, this isn't a real issue.

-- Scott Walton (scotlynn@shore.net), May 08, 2001.


Common developers can be diluted to reduce the solvent effect of Sodium Sulphite. D-76 [or ID-11] for example, diluted 1+3 ends up with 3.25% SS by Cesar's numbers. You could experiment with even higher dilutions.

There is, of course, one other way to minimize grain in a given [silver image B&W] film: don't overexpose. Just enough exposure for adequate shadow detail.

-- Tim Brown (brownt@flash.net), May 08, 2001.


All colour developing agents are paraphenylene-diamine derivatives. You could use the developer from a C-41 kit as a readily available PPD developer.
I experimented with a PPD hydrochloride developer in the dim and distant past. Results were fine grained, but not excitingly so.
The 'underdevelopment with a high contrast developer' idea is a non-starter.

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 08, 2001.

George:

If you want the finest grain possible, combine Ed's and Pete's suggestions and develop Tech Pan film in C-41 developer. After development, the remainder of the process is the same as with conventional B&W. The grain will be so fine that you won't be able to use a grain magnifier when you focus your enlarger.

-- Ken Burns (kenburns@twave.net), May 09, 2001.


That should be 2.5% not 3.25% in my last post.

-- tim (brownt@flash.net), May 09, 2001.

My focus is to get the finest grain from standard films like TriX or Delta100. Im intruiged by the idea of using a C41 developer. I also might try using Emofin as a single bath. The first bath seems to contain phenylenediamine and sulphite (not sure what kind maybe they mean bisulphite) and bath two has sod. carbonate and sodium sulphite. For that matter I might even try it as a two bath while Im at it!

George

-- George Paltoglou (stellar@optusnet.com.au), May 09, 2001.



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