The developing procedures for Diafine (off the box) call for at least 3 minutes in each solution and 5 sec's very gentle agitation in both solutions at the beginning and once every minute. Since it takes 5 sec's to fill my daylight tank I skip the first agitation schedule. You might want to filter the solutions with a coffee filter to get the residue's out and I like the idea of mixing the solutions. I suggested a longer "A" solution soak as I remember some film I used once having the same problem as you notice.
That's fine as long as following the procedure works. But as Thomas encounters a certain problem which possibly can (can: to take in account that YMMV ) be cured by changing the agitation-scheme, I'd not take that word for gospel. The proof is in the pudding.
Originally Posted by waynecrider
Here's another possibility: some users may believe that no development occurs in Part A, but my understanding is that if Part A is alkaline enough, development will occur. Adding Part B kicks the development into a higher level of activity. So if the film is not fully agitated when in Part A because it's "only" soaking up solution, then perhaps that's why you see uneven development once you've completed the A/B cycle. Just a thought!
I've found that with Diafine less agitation is always better. If I do a couple rolls in another developer and then come back to Diafine, I have to constantly tell myself to just sit the tank down and leave it alone.
So many misperceptions.....
I've been putzing with divided development for years. I like the "Zone System for roll film" ability, so to speak. I never got the negative density with Diafine that I want, and have moved on to other formulations. But here are some facts about Diafine and its use. Except as noted below, agitation really has no place or bearing in divided development in either solution.
1. The Darkroom Cookbook has a Diafine copy; it is a P-Q formula. I have no knowledge if it is indeed a copy or just gives similar results.
2. The pH of Diafine Bath A is 8.25. This is WAY below what will give any development, even with Phenidone, unless you left it in there for hours.
3. The Bath B is about 10.5. The MSDS show that sodium carbonat is a component, I'm guessing probably the only one. Five grams per liter will give you 10.5 pH.
4. As some here have said, "no" development takes place in Bath A. All we are doing is getting the emulsion to accept developer. Agitation means nothing in this step, overlooking possible air bubbles. Agitate continuously if you want, or just let it sit. Or as I do as a CYA, every minute or so just to make sure there are no bubbles preventing absorption. The warmer the developer, the faster this will happen.
5. If Diafine is a PQ developer, or even MQ with highly active ratios (1:9 and 1:4 respectively), the Hydroquinone is more active at the higher temperatures. This means more contrast as the temperature goes up. It is not a true panthermic developer, although much more so than traditional developers.
6. Agitation in Bath B should be minimal to none. Agitating undoes the very characteristics we are looking for in a two bath developer. As someone pointed out, at the least, it will wash Bath A out of the emulsion. Also, it will bring fresh developer action to the highlights, which will cause less shoulder. While certainly the box suggestions are a starting point, try using less to none at all.
7. Time in baths is of minimal consequence. If you want some control, try using different temperatures (both baths the same!) If the developer is cool, there will be less swelling of the emulsion and hence less developer to work with in Bath B. If your negatives are thin, try developing at 75 or 80 degrees. More time in Bath B pretty much just causes more grain; more time for the silver filaments to grow without any corresponding increase in density. Someday I'm going to do some experiments on this matter but I would wager that 95% of the development is done by a minute in Bath B.
In my two bath work, I pour in the Bath B, rap the tank onto the counter a few times, then let it go to work. Never a bromide drag problem with my current formula, which has a lot of potassium bromide in it. If you can get away with this with Diafine, by all means do it.
Of late I've used a two bath by that old school photographer-journalist, Otha C. Spencer. (Does anyone know if he is still alive?) I kept an article by him from 1992 where he tells about his formulation. Since I've not been able to enlarge my negs, I can't yet say anything about grain, but he claims 11x17's "without grain." (Film speen unstated.) But I do get very printable negs from two stops under to two stops over the native ISO! Two minutes in each bath and it's done.
Mi tres centavos....
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
I have mixed feelings on Diafine. It's works well with Tri-X, especially to obtain a speed boost but I find that it produces fairly significant fog, even with minimal agitation. However, being a panthermic 2 solution developer makes it very versatile.
"The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."
Nuts... I have developed a thousand rolls in Diafine, with never a problem, and I read this thread and wouldn't ya know, I got 2 rolls that look just like this. Same bromide streaking...
I am of the opinion that it may be caused by the either lack of enough agitation in bath 2 or by the time taken between the emptying of bath 2 to the stop bath. I have a tendency to be slow emptying tanks, and I think I had taken longer letting the tanks sit "empty" before immersing the film in the stop.
Paul Verizzo, I agree on most of what you are saying. I have a question @ though. If the amount of developer in the emulsion is the limiting factor and develops until exhaustion (in the highlights) how can temperature lead to more contrast? as far as I understand higher temperature will only lead to the exhaustion faster? Or am I missing something?
Send from my Electronic Data Management Device using TWOFingerTexting
Technology distinquishable from magic is insufficiently developed
Paul: What's the formula as specified by Otha C. Spencer? Thanks.
There seem to be a lot of differing opinions about how to develop in Diafine- I want to start developing my own B+W, and want to start with diafine- what should I look out for? any tips?