I have been using Thorntans variation, and really like it. With roll film hp5 + and fp4 it works very well, just as described in his book.
I am in the process of tuning it for acros. I have not done full testing yet.......
I will publish an article in the coming days on high res films like Pan F and Rollei Pan 25 and a new way to run these films for the best contrast control and even development. I know Divided D23 also works fine with most of these films but Diafine produces a more linear curve with a lower contrast gradient around .47 / .48 on most films.
Best-
Stephen Schaub
I made up some of Barry Thornton's 2-bath before buying the Diafine.
Out of curiosity I weighed the contents of the diafine bags before disolving them. They were exactly the same total as the Thornton 2-bath. No proof it's the same stuff, of course but the results look identical, too, to me.
Maybe with more sophisticated test gear than my eye, differences would show so I won't comment about that!
Murray
Under agitation in Part B will produce bromide drag. Films where agitation in both A & B are important (this is gentle agitation with inversions) include: Rollei Pan 25, Ilford Pan F Plus, TMAX 100, FUJI Acros, Efke 25 just to name a few...under agitation in any of there films is a quick path to bromide drag and possibly uneven development. Faster films like TX, 125PX, TMY 400(new), HP5 ect suffer much less from bromide drag and agitation in A and B are not as much of an issue.
I stand corrected. I hadn't thought to check the 'net for the MSDS.Diafine and Thornton's DD are very different. Although the exact formula for Diafine has never been released, it's pretty obviously a Phenidone-HQ-sulfite Bath A and a sodium carbonate-sulfite Bath B. That info is from the MSDS's, visible crystal structure, pH of solutions, and behavior. By that, I mean the ability of Phenidone to develop grains with minimal exposure, hence, increased EI.
Thornton's is a D-23 type DD using Metol as the sole agent. The longer tank times for faster films is probably for grain reduction more than anything, more time with the sulfite.
Thanks for all the information. I'm getting a bit confused about the agitation though. Anchell & Troop say continuous agitation in A and B for all the two bath formulae in The Film Developing Cookbook. Is this just wrong?
Cheers
Ritchie
A follow up; I am of the mind that Thorntons version of divided d23 may not be the best choice for Acros.
Even at ei 50 I find the shadows blocked up, (underexposed), and to get enough contrast to print on a #2 paper, I had to add metaborate to the second bath. The result looks to me like underexposed, overdeveloped, low quality negatives. The stuff is very sharp however.
I my try Diafine as I have some on hand..........
I also agree that in an ideal world no agitation is required with DD but when does that happen? Diafine on most new emulsion films I have tested needs some agitation to prevent Bromide drag...TX may be the only exception I've found and even with it I'd rather be safe than risk having a neg wrecked by Bromide Drag or uneven development.
I recon there is exactly the same amount of bromide liberated whether a two bath or single bath developer is used so I agitate Thorntons 10s/min in both baths, agitation as for a single bath developer,to avoid streaks.
I find Thorntons gives a speed loss of about 1/3 stop compared to D-76,Barry Thornton mentioned the Stoeckler loses speed in his book 'Edge of Darkness'.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?