Diafine expert about?

[snaggs]

I have a friend who runs a small drug discovery company and has a proper lab. He can mix me up whatever developer I want using magnetic stirrers etc, from bulk chemicals, which will make some developers very cheap for me.

I have 3 x 70mm backs for my blad, and 500ft of Double-X Aerial film and 600ft of Plus-X Aerial film. I havn't got my 70mm reels yet, so I havn't had a chance to play. However, I will need new tanks as I've just got a tiny 35mm paterson tank.

Since the film is high contrast and old style (1969 formulation) Kodak, I'm thinking Diafine is going to do a good job of this. My plan is to use 7 or 15 litre Kodak style square tubs (3F or 7F), and lower my reels and sheets on racks into this. Since I've read that Diafine basically lasts forever, and my chemical costs are cheap, I was thinking just to leave these 15L tubs filled with Part A, Part B and Fixer. Even maybe putting in 3 deep tanks (82cm) as part of the sink.

However, my question is, how long do these chemicals keep and do they need vacuum sealing to keep. Or will just the lids on top suffice?



Daniel.

 

[bernard_L]

From long-ago experience Diafine is a particular developer for a particular purpose: pushing. Accordingly, it limits the contrast of highlights. The resulting images, from what I recall, have a characteristic look of compensating developer: the highlights are dull. If you want to mix your own, why not D76, seldom surpassed by other fancy formulations. Use 1+1 one-shot. 10min @20°C as a starting point; then define your preferred time, probably in the range 10-12min.

 

[snaggs]

Well, I've read a few articles on Diafine and Tri-X which convinced me. Low stress, and allows ISO changes mid roll, which is usefull with 70mm 120 shot backs. It also lasts forever, so I don't have to throw away 15 litres each month. Don't need temperature control, or time control. It will also tame the high contrast aerial film I have (it does with other films, so Im hoping it will work equally well)

Even better, if it doesn't go flat in tanks with lids, I can put 3 deep tanks in and use racks instead of spirals. Hoorah!

If no one knows, I might just have to try for myself and post the results.

Daniel.

 

[ntenny]

Diafine B is basically just an alkali solution, so I think there's every reason to expect it would last until the end of the world. The A solution with the developing agents does fail eventually, but there seems to be a fair amount of variation. Mine has generally lasted on the order of a year, but I've seen people say they were still using a batch successfully that was 5+ years old. I think basically everyone keeps it in bottles that are at least close to airtight; your "semi-open-air" proposal might be the first of its kind.

Personally, I don't find that it causes dull highlights in a visually obtrusive way when used as a contrast-taming developer in the way you're suggesting. Tri-X in Diafine does have a very distinctive look that either is or isn't what you want, but it sounds like your main target is the aerial films anyway. I think it's worth pursuing, but you should definitely do a few test rolls first to see how it works.

You said the film is "old-style", but is it in-date? In my experience, Diafine can be a problem with outdated film, because it doesn't control fog worth the proverbial hill of beans.

-NT

 

[Jeff Searust]

part A is absorbed by the film at the rate of a bout an oz for every 120 roll of film -- I would have no problem with the way you are describing your setup --- water for stop would be fine also -- you may want to plan for 5 baths. A, B, a water stop/rinse, fixer, and then another water with flowing water for a final rinse. after that, a quick run through photo-flow and hang to dry.

 

[snaggs]

part A is absorbed by the film at the rate of a bout an oz for every 120 roll of film -- I would have no problem with the way you are describing your setup --- water for stop would be fine also -- you may want to plan for 5 baths. A, B, a water stop/rinse, fixer, and then another water with flowing water for a final rinse. after that, a quick run through photo-flow and hang to dry.

Ok, that sounds like a good idea. I guess topping up the Part A each time would help keep i alive? Also, wont the film be hard after fixer though, so I could just have a general water cascading bath as part of the sink that could be used for paper as well?

This is the part that is confusing me, all the various sink configuration options shown here;

http://www.richards.uk.com/wetben02.htm

 

[snaggs]

You said the film is "old-style", but is it in-date? In my experience, Diafine can be a problem with outdated film, because it doesn't control fog worth the proverbial hill of beans.
-NT

it was kept frozen, has expiry of 11/2008. There was a discussion about whether this film would keep on the web, and some guy had spoken to Kodak who said if you freeze this film your grandchildren will be using it. So should be good for a long time.

Daniel.

Ps. Heres one th aticles on Diafine Ive read, http://www.blackandwhitefineart.net/2011/01/diafine/