2 bath devs

Markok765 · Jul 28, 2006

Ive hreard of split devs eg diafine, and was wondering would i be able to uxe xtol as a 2 part dev? first part a then b?

Ryuji · Jul 28, 2006

Wigwam Jones · Jul 28, 2006

Split developers are either designed that way (Diafine, Cachet AB55, etc) or they are 'mix it yourself' kind of developers where a divided bath is desireable for one reason or another, such as 'Divided D76'. When the developer comes in a single pouch of powder or bottle from the maker, there is nothing to divide, unless one is talking about an additive - in which case it is not a divided developer.

Markok765 · Jul 28, 2006

Ryuji said:
No.

Why? Xtol comes in 2 packages

Bob F. · Jul 28, 2006

Markok765 said:
Why? Xtol comes in 2 packages

Because the fact that Xtol comes in two packages is irrelevant - that's probably just to keep one lot of chems away from the others - ID-11 is similarly packaged.

The two baths in a divided developer have specific jobs to do. Generally, the first bath contains the developer and the second bath contains the accelerator (I'm speaking generally here note: look it up for the details of the use of preservatives and restrainers). The film is soaked in the first bath so the emulsion soaks up the developer - relatively little development takes place here. You then transfer the film to the second bath accelerator where, as the name suggests, the developer in the emulsion is kicked into high gear and completes the development of the film.

Cheers, Bob.

nworth · Jul 28, 2006

It would be impossible wit Xtol, because Xtol is a packaged product. You might be able to adapt a clone, like Mytol, however. The basic idea of two-bath developers is to separate the developing agent and the alkalai. It isn't quite that simple, however. Anchell and Troop, "The Film Developing Cookbook," has an excellent section on two bath developers that you might want to read.

david b · Jul 29, 2006

hey marko, do you proof-read your threads before posting them? Your thread has 3 typos in one sentence.

waynecrider · Jul 29, 2006

Read this:

http://leica-users.org/v13/msg12048.html

Alan Johnson · Jul 30, 2006

Here's a 2-bath developer that contains ascorbate like Xtol.
It goes off (goes orange and gives thin negs) quite quickly (about 2 months) even in absence of air in the container,probably due to the decomposition of sodium ascorbate.I don't know how this problem was solved with Xtol.
Part A: Metol 6g/L or Phenidone(dissolve in 100ml isopropanol) 1g/L
..........Sodium Ascorbate 50 g/L
Part B: Sodium Metaborate 12 g/L
Develop 4min part A then 4 min part B 68F Agitate 30s then 2 inversions/30s.
Stop,Fix,Wash.

jhorvat · Aug 3, 2006

In principle, almost all developers could be used in two-bath fashion, even though this is not "two-bath" process strictly speaking. The first bath contains normal developer (could be Perceptol etc.) and second is accelerator. FIrst bath should be used for the time that gives highlights almost fully developed. Then, film is treated in the second bath (borax would do) for 4 or so minutes. This bath gives detail to the shadows, activating the developer that is absorbed by the emulsion. The highlight areas will also get some extra density, but this will be much less than in the shadows, compared to the density of the respective areas.
The Stoeckler formula, that is often used for this purpose, does the same. The part A WILL be active in the first 4 minutes of development/soaking-the solution is alkaline enough thanks to the sodium sulphite.
Along these lines, my guess is, Xtol may also work in similar way. The trick is to adjust all the parameters: developer strength, film emulsion characteristics (including thickness), exposure, temperature and time in bath A to get required results for a particular shot....

Roger Hicks · Aug 3, 2006

Dear Marko,

The short answer is no.

A rather longer answer is 'Why would you want to?'

Two-bath developers are a favourite of 'magic bullet' seekers, and an awful lot of their mystique is pure fantasy -- though it is undeniably true that some people get excellent results with some two-baths.

The first bath contains all the developing agent, but with only enough sulphite to stop it oxidizing, i.e. it is very slow-acting. You can develop the film in this bath only but typically you might need four times the normal first-bath time. The second bath is the accelerator, in which time is rarely critical: it commonly acts until all the developer retained in the film has been used up.

The last time Ilford looked at this, a few years ago, they came to the conclusion that anything you can do with a 2-bath, you can also do with a dilute developer. I used 2-bath devs 30+ years ago, but when I tried my old favourite with more modern films I saw no advantage.

Your mileage may of course vary. There is at least as much alchemy in B+W as there is science. But equally, the fact that a developer was compounded by a teenage virgin during a full moon does not necessarily mean it has any remarkable properties.

Cheers,

Roger (www.rogerandfrances.com)

titrisol · Aug 3, 2006

I think Roger has summed it all up.
IMHO the only reasons to use 2 bath developers is:
a. Becasue they last a long time (Diafine specially)
b. Becasue they are easy to use
c. Becasue your shots have a huge contrast range and need the compensation

fhovie · Aug 3, 2006

The trade off in 2 bath developers is (my observations by using them)
- less accutance
- little or no control of expansion or contraction
Highly dilute devlopers will give the compensation of 2 bath developers with greater accutance but also with a little more grain. 2 bath developers have their place - classic cameras with no exposure control and seat of the pants exposure guess-timation produce film that works well in 2 bath. It can save an impossible roll of film. I do use two bath devleloper - split d-23. It is never my first choice for creative art.

Gerald Koch · Aug 3, 2006

Since the development time is the same for any film, two bath developers are useful when you have an unknown film and need to develop it.

Roger Hicks · Aug 3, 2006

Gerald Koch said:
Since the development time is the same for any film, two bath developers are useful when you have an unknown film and need to develop it.

Dear Gerald,

While I'd certainly agree that a two-bath is a great solution for an unknown film, a lot depends on emulsion thickness/hardness as well as speed. Many (most?) two-bath formulae call for twice as much first bath soak time for fast films as for slow.

Cheers,

Roger

2 bath devs

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