Uneven Developement with Diafine - how to test properly?

[Leigh]

I did not presoak this time

Hi Christoph,

You absolutely CANNOT use a presoak with Diafine. It says so in the instructions.

Diafine works by absorbing Part A into the dry emulsion, then having Part B work on that chemistry.

I realize that does not pertain to the current example.

What film? Is it fresh (before the expiration date)?

This really has me puzzled. I've developed thousands of negatives in Diafine with no problems.

- Leigh

[zechi]

Hi Christoph,

You absolutely CANNOT use a presoak with Diafine. It says so in the instructions.

Diafine works by absorbing Part A into the dry emulsion, then having Part B work on that chemistry.

I realize that does not pertain to the current example.

What film? Is it fresh (before the expiration date)?

This really has me puzzled. I've developed thousands of negatives in Diafine with no problems.

- Leigh

I know that I'm not supposed to do a presoak - and I didn't this time. I presoaked before because I got uneven developement without it and wanted to give it a try .. but with the negative I attached to my last post, I exactly followed the box instructions. The film is Fomapan 100 and it is not expired and has always been in the fridge, in a zip loc bag ... maybe it's the water? I used distilled water for mixing the chemicals and also for the final rinse with the wetting agent. But I used tap water for rinsing after B .. We have quite hard water here, maybe I should try with distilled water?

Leigh, how do you develope your 4x5 sheets in diafine? in a tank or tray? I tried tray developement too, but with the same poor result ..

Christoph

[Leigh]

Hi Christoph,

The tap water after Part B should not matter, as development is complete by that time.

I've never used distilled water to mix my developer, but it does not hurt to do so.

I'm sorry. You mentioned the film type in your first post and I missed it.
I'm not aware of any issues with Fomapan. I don't use it, but I know many people do without any issues.

I use square tanks or trays, depending on how many films I need to develop.
The tanks will hold 12 sheets, which is more than I can do conveniently in trays.

I did use a Nikor round tank for a while, but found it difficult to load.
Also, the fill/dump time was excessive IMO.

I find your problem to be particularly aggravating because I can't explain it.

Regarding agitation...
Diafine is a compensating developer. Developers of this type work by exhausting the developing agent in areas of high negative density, which is why they want very little agitation. Vigorous agitation replaces the active chemistry across the entire negative very frequently, which defeats the compensation action.

You can use more vigorous agitation if needed, but you will lose the compensating effect.

- Leigh

[Kevin J. Kolosky]

why is Diafine so expensive?

[Leigh]

why is Diafine so expensive?

Huh?

It lasts forever.

You top off both parts with fresh from stock to replenish.

- Leigh

[BetterSense]

My last batch of Diafine was mixed in 2009. It had dwindled from a gallon to less than a litre from attrition when I dumped it in 2013 to move. It's very cheap on a per-area basis, but even so I haven't brought myself to spring for a new gallon.

[Leigh]

It had dwindled from a gallon to less than a litre from attrition when I dumped it in 2013 to move.

The standard replenishment technique requires that you start with two bottles full to the brim, or with a volume that you can measure accurately.
That volume is your working stock, used for actual development.

After each development session, you add enough fresh Part A stock solution (from a separate stock bottle) to restore that original volume, noting the volume of fresh stock required to do so.

You then add the same amount of fresh Part B stock to its storage bottle, then return enough used Part B to restore its full volume, discarding any excess.

You can continue this regimen indefinitely. When you run out of fresh solutions, buy another 1-quart box and mix it.

- Leigh

[Renato Tonelli]

Leigh - Are you following the box instructions as far as the Exposure Index goes for Diafine and LF?

I have been using Diafine (and sometimes its cousin Acufine) with 35mm Tri-X for close to 20 years (as per instructions on the box) and I am tempted to try it with 320TXP (4x5 & 5x7) just for kicks... I need a little encouragement...

[Leigh]

Hi Renato,

I shoot everything at box speed. I don't use any film faster than 100ASA.

Diafine is a compensating developer when used with minimal agitation as instructed.
As such it works well with films shot at lower EIs than the box values.

- Leigh

[Renato Tonelli]

Leigh - thank you for your generous advice.