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Discussion in 'B&W: Film, Paper, Chemistry' started by timeUnit, Oct 12, 2005.
Is it so that increased ditution of a developer increases grain and reduces contrast?
Photography is a system: changing 1 component has little effect on the outcome.
If you change the dilution of Rodinal, for instance, from 1+25 to 1+100, you will get the exact same image IF you adjust the agitation and time.
The age old 'wive's tale' of compensation is generally traceable to the reduced proportion of agitation given to the longer development time required of a greater dilution.
Perceptable grain is usually determined by the amount of over-agitation given to film. Which is one of the reasons Rodinal has been used for decades with reduced agitation.
But it is not accurate to attribute contrast and grain difference only to dilution.
So many people seem to recommend say XTOL at stock to get finer grain than at 1+1 or 1+2. The same with D76.
"Perceptable grain is usually determined by the amount of over-agitation given to film."
If that is true, a shorter development at a higher concentration would give more grain., since:
"...reduced proportion of agitation given to the longer development time required of a greater dilution."
This contradicts what most people here or elsewhere say.
Are there hard facts on this. Any books to read?
The basic silver grain size is manufactured into the film. Sulfite is a silver solvent. High sulfite developers (like D-76), when used undiluted, tend to dissolve the edges of the silver grains - thus reducing sharpness/acutance. Diluting a sulfited developer with water reduces its silver solvent characteristics - thus producing a better defined silver grain structure and higher acutance.
According to Kodak, undiluted Xtol is a higher acutance developer than undiluted D-76.
".......XTOL at stock to get finer grain than at 1+1 or 1+2."
This is asserted in the Xtol data sheet as well. Supposedly it has to do with the developer acting as a solvent on the film grain (I hope someone more technically versed in this will chime in). At reduced concentration this action is reduced. Personal experience has shown this to be correct. The effect is obvious with TMZ or Delta 3200. Keep in mind that the reduction in granularity comes with its own price in acutance, and that not all developers have this solvent action. Your own testing should guide you as to how valuable this feature is.
Nothing like trying yourself. Rodinal may not change much but it does change. At 1;25 the grain has sort of a mottly appearance. At 1:50 it looks sharper. The appearance of a D76 print changes when developed to the same contrast/gamma. The grain thru a grain magnifier may look the same, but the prints are different.
If you look at them in a decent optical microscope, the silver grains that result from developement in undiluted D-76 do not look the same as a sample of the same film developed in diluted D-76. The grains developed in the undiluted D-76 are smaller and have diffuse or fuzzy edges. This is due to the silver solvent properties of the high concentrations of Sodium Sulfite found in D-76 (and many other developers).
A detailed discussion of this subject in can be found in pages 414 - 424 of Modern Photographic Processing, Volume 1, Grant Haist, 1979, John Wiley and Sons, Inc.
Grant Haist was the Director of Research and Development at Kodak.
So I get less grain, but at the expence of "percepted" sharpness if devving in undiluted XTOL or D76? Does actual resolution change?
Part two of the question is that diluted developer gives lower contrast, I guess because of proportionally less agitation? I.e. a "compensating" effect, where the developers exhausts itself on high density areas, but keeps working in midtones and shadows. True?
Could one say that in stock XTOL my acros films will have little grain and high contrast, but maybe lack a bit of sharpness compared to XTOL 1+1? In 1+1 they will be flatter but sharper?
That Modern Photographic Processing seems like a nice bible. Will check out.
Thanks for all replies!
Yes, the resolution (and acutance) is reduced. See Haist.
It is actually more complicated than that. Agitation also plays a strong role as does the film and the properties of the developing reagents.
I would say that in stock XTOL your ACROS will have good acutance, a good tonal scale and fine grain. At 1+1 the results should be similar, perhaps with slightly larger grain and slightly higher acutance.
You need to try it undiluted and diluted and decide which you like best.
That book(s) are really expensive - I saw a set on e-bay used for $600. Contrast has to do with development time and aggitation. Strength of chemistry will cause a change in contrast if it becomes exhausted. Uncontrolled developer exhaustion is not usually a recommendation. You can used dilute developers without exhaustion by using more volume. The reason that with some developers, grain becomes more apparent when dilute is because of Soduim Sulfite. When the dilution of Sodium Sulfite drops below 80g per liter, it dissolves a lot less silver giving sharper grain. The reason XTOL doesn't give mushy grain full strength is because it has less sulfite than D76. It is right at the cusp full strength. The thing to remember is that different developers work differently. The staining chemical in Rodinal is very different than the isoascorbic acid in XTOL.
After a time of reading posts on this forum, you will get familiar with the strengths of different chemicals. Pyro chemicals are very different in their effects than Metol, Phenidone or Ascorbic Acid. Knowing the differences between how these chemicals are used will help you choose the soup for the effect you want. - Which - you haven't actually stated.
Roll film? 35mm? sheet film?
Do you want full film speed?
Do you want highlight clamping?
Are you trying to capture light from f1.4 to f32 in the same image?
Are you trying to expand a low contrast scene?
How big will you enlarge?
Will you use VC paper, FB paper or AZO?
Do you like gritty grain or very smooth tonality?
Do you want sharpness that will cut you or are you looking for gentler edges?
Are you putting very different challenges on the same roll of film?
I consider all these questions or more when I choose a chemistry. I chose from the following based on the answers to these questions:
PyrocatHD - XTOL - Microphen - Split D23 - PC-TEA - 510 Pyro.
- I have data on all of these to exploit their strengths in many situations.
It was just a general question.
There seems to be so many different opinions and concepts on grain/contrast/resolution/dilution so I thought I'd ask as straight as possible to see what people say.
I myself use XTOL and Rodinal, but I'm learning about other developers as well, especially when reading here on APUG. I use XTOL at 1+1 mainly, and it has given me great results for many 135 films I think, but for medium format I find it too fine grained, especially on slow films. What I'm looking for when using slow films is "medium" contrast, and high sharpness. I find that at 10 by 10 inch enlargements, my MF pictures are totally grain free and almost "unsharp" when using acros or pan f. I was thinking that by using a grainier/sharper developer like Rodinal I would get that sharpness I'm looking for, even at 10 x 10. I will see when I slip into my darkroom tonight.
Thanks for your time!
You've turned your initial question inside out. Asking if dilution increases grain is one thing. Assuming that it reduces grain is another. In particular, with a sulfite rich developer like d-76 or xtol, the stock solution tends toward less shadow speed and a less acute image. This is hair splitting, and with a film like Acros ot TMX, almost a pointless distinction. Reducing the amount of sulfite ( by dilution ) gives a slightly 'faster' film, and slightly more acute. With D-76 and Tri X, you'll see the difference in the print. With Acros, probably hard to discern.
Rodinal is NOT a sulfite rich developer, so reducing the amount of sulfite by dilution will have no effect, because there is not enough to soften the grain in the first place.
Using Xtol and Rodinal to compliment each other is a good plan. Be your own judge: but I'd suggest making your decisions based on real prints, at your normal sizes. Often folks go to extremes when discussing developers, willing to argue forever about PMK vs Rodinal vs FX2 with Tri X... and all the while glossing over the fact that you need a 16x enlargement and a strong magnifier to discern the difference.
Make pictures, and don't get bogged down.
I have not turned my initial question inside out. I did not know the difference in sulfite content between XTOL, D76 and Rodinal, and therefore used what you wrote to get further understanding. Now with your explanation I understand better about Rodinal and XTOL. Thank you.
I agree that I must make my own decisions regarding what developer to use. It seems though that I had gotten it backwards, thinking that more diluted XTOL would give less grain, as it's "milder". Now I know better.
Good thread, this one. Lots of great info.
My aim right now is to get the slow films as sharp as possible, as I _like_ grain in my pictures, but also love the detail from MF. Any suggestions?
DS-12 was made for that purpose. If DS-12 sounds too complicated, try DS-2. Both are published metol-ascorbate developer formulae. If you are developing Acros, I recommend to dilute either of these developers 2+1 (2 parts dev, 1 part water) or 1+1.
The reason why D-76 stock gives less accutance than diluted solution has to do with antirestraining action of large amount of sulfite. Solvent action itself has little effect on the accutance, as it is occuring at the level of individual grains, which is too small to be resolved via enlarging system. (Most common AgX solvents have some antirestraining effects. Thiosulfate added to developer is particularly effective for this.)
There are lots of myths about solvent developers, fine grain developers, physical development, accutance, etc. For example, if you don't do it carefully, solvent developers with significant physical development activity can only make your image look grainier. There are some formulators who claim sulfite in developer doesn't contribute to fine grain effect, etc. but it often happens that their development condition is not suitable for fine grain effects. For example, if you add sulfite to D-19, you're not going to get finer grain like you would see between D-76 with 50g/L and 100g/L sulfite (pH is to be held constant for this comparison).
Accutance effect is amplified by enlargement. That is, given same film, development and print size, you'll get more accutance effect from smaller format films.
I personally prefer DS-10 (not too dissimilar from XTOL) stock or 1+1 for most 35mm films, and DS-12 for landscape work on slow medium format films. The closest developer you can buy (to DS-12) is Ilfosol S, but this developer is notorious for short shelf life once opened. So you might want to try out Ilfosol S, and if you like it, you might want to mix DS-2 or DS-12 yourself.
Contrast is a different matter. You can develop your MF films to the same contrast in your XTOL. You just have to adjust temp, agitation, time, or combination thereof. I generally develop 35mm and MF negatives to the same contrast. I enlarge 35mm films to 11x14, and MF films to 20 inch square in typical situations, so they are usually enlarged to about same magnification.
You can buy a set of new copies directly from Grant Haist for the price you expect for new copies. PM me if you are interested. I won't post this info because I only have his home address, etc. (But if there are enough requests, I may call him and ask for his latest price and POBox so that I can post them...)
This is not really the case as I posted previously. The reason XTOL doesn't give mushy grain full strength is not because of sulfite. You should add 20g sulfite to XTOL and see if you get grains like D-76. The reason certain ascorbate developers give finer grains is related to the electrochemical condition of development, and also the difference in the behavior of oxidized developing agents.
Ryuji: cool, thanks
I believe I read this response in "The Film Developers Cookbook" and it does seem to fit the observations. I am not a chemist and always apprediate your input. I would like to understand better some of this chemistry myself. Also, I had heard those books were out of print and were only available used. I would be interested in knowing what their availability is - they are listed as out of print at Amazon. Maybe there are others as well that would be interested in them.
I'm talking about Haist's two volume set that you can buy in new copies. He worked out with the publisher to print his own book after the book went out of print. He has a stock of new hard bound copies printed by a different printing firm available for sale. The books look identical to the original published form, except insertion of a page describing this reprint edition.
It didn't come to my mind in my previous post, but I actually had DS-1, whose formula is: 2g metol, 5g ascorbic acid, 100g sodium sulfite, 12g borax in a liter of water. The pH is comparable to D-76 (8.5 to 8.6). You can use this developer just like D-76d. Develop a roll of Tri-X or whatever, split them, and develop them in D-76d and DS-1. Pick ones with same contrast, and check out the grain at 10x magnification. DS-1 doesn't have the mushy grain of D-76d stock strength. I did that comparison 4-5 years ago. Unfortunately DS-1 doesn't keep very well and can suffer from the same problems as XTOL.
How would you comapre DS1 to PC-TEA?
I don't use PC-TEA in my practice. Gainer does not specify target pH for this developer. Sandy King measured the pH of PC-TEA, and triethanolamine is a wrong buffering agent for that pH. N-methyldiethanolamine or N,N'-dimethylethanolamine would be a better choice depending on the target pH intended by the formulator.
DS-1 is a good developer similar to D-76d. Differences: (1) DS-1 produces fine grain image like D-76d, but without mushy grains. (2) DS-1 is less reliable when kept, in light of XTOL failures and lack of any active means of preventing the problems in DS-1. The latter can be fixed, so I could issue a new version of DS-1, but I decided not to pursue that direction because DS-10 produces superior image quality with almost all films except APX100. (and I think Martin Jangowski found a couple more films that don't work well in DS-10.)
DS-1 can also be comapred to XTOL. Differences: (1) XTOL provides slightly finer grain. (2) XTOL provides slightly higher true speed.
After all, DS-1 is a good general purpose developer if you don't mind mixing from scratch, but otherwise, there's not much worthy of comments. (Therefore I don't mention it very often.)
total system angular momentum
My original intent in writing the article for Photo Techniques was to devise a split stock developer that might extend the storage life of ascorbic acid developers. Using TEA as solvent was an afterthought that works and provides a single solution developer with long storage life. There are many developers with little buffer capacity. If a target pH and large buffer capacity are considered necessary, the split stock idea with the developing agents in a glycol solution allows the use of any other solution as activator, etc. A plain 10% sulfite solution will give results similar to D-23, for example. Add a borax-boric acid or any other buffered alkali buffer if you want. These second solutions usually keep well and thus need not be incorporated in the glycol solution.
Another idea is to use propylene glycol as the principal part of the solvent with just enough TEA to "neutralize" the ascorbic acid. I doubt that a pH meter's reading of that solution would accurately tell the pH after water is added, but I think that with 99% TEA a pretty good guess could be made as to how much to add to the first solution. The major impurity in TEA, according to Dow, is diethanolamine. I'm guessing that equimolar amounts of ascorbic acid and TEA would be close enough for government work.
If I am right in assuming that the major cause of change in pH during development is products of the development reactions, and one-shot use of the working solution is the rule, and each person using a given developer will find time-temperature relationships to suit, then change of pH will be very nearly the same for each use and will not be an issue after the first determination of operating conditions.