How many reels in a developing tank?

Cor · May 9, 2007

Somewere I picked up the notion that one should ones developer tank (this is manual inversion with a say Paterson tank or rotation development with a JOBO) with the maxium amount of reels.

So if one would proces only 1 film in a JOBO 1502(?) tank, which can accomodate 2 reels, one should add a empty reel.

The same for the Paterson, but that is les of a "problem" since I have those in different sizes and I take the smallest needed.

Reason for this, as I recall, a better flow of the developer (I guess it does influence the flow over the neagtives of the developer).

I was wondering lately if this is an urban myth, or do others also follow this practice.

Best,

Cor

(ofcourse it's no big deal to add that extra reel, as far as I can tell it does not harm)

Ondrej1 · May 9, 2007

I regularly use only one reel in Jobo 1520 and see no problem at all. I think the reason to have all reels in tank is to disable reel slip, especially with inversion development, but I never had dis problem, reel holds very well.

frugal · May 9, 2007

Depending on your tank your reels might slide inside the tank, in which case you'd want to fully load it. With a Paterson tank that's probably not an issue. I know I've had it happen with stainless tanks though (was just a bit of sliding, not along the full length).

gainer · May 9, 2007

I use a 2-reel stainless tank with only one reel, and agitate by inversion, but I fill the tank with solution. The sliding of the reel from bottom to top and back adds to inversion, but I am one who does not believe in "gentle" agitation. I think it is more likely to result in uneven development than vigorous agitation. The exception is when I use extremely dilute developer with extreme minimal agitation. It's all a matter of opinion and experience. When my opinion does not lead to bad experiences, I stick with it.

Snapshot · May 9, 2007

I side stepped this issue by purchasing a 1 reel, 2 reel, 3 reel and 5 reel tank. I guess it would be a problem if I had 4 reels but I could always develop film with the 2 reel tanks twice.

AgX · May 9, 2007

The problem with such rules or myths is that it is not clear what is referred to:

1 reel loose, with partly filled tank,
the same, fully filled,
1 reel fixed, partly filled,
the same fully filled,
2 reels, 1 with film etc. etc....

And for all one could think of a theory. I guess!! for a two reel tank 1reel, fixed, half filled and 2reels, fully filled would be the extremes, if at all.
If constantly keeping our manner of inverting the tank any differences due to loading the tank could be visible.

But in discussions as these I think we schould be more humble in that we yield any images at all. It is still fascinating to me...

Dietmar Wolf · May 9, 2007

Sorry, but a similar question:

How many films on one reel, esp. in the jobo tank.

Did you experienced bad/other results with two films on one reel?

AgX · May 9, 2007

Do you mean `back to back´?

Cor · May 9, 2007

diwolf said:
Sorry, but a similar question:

How many films on one reel, esp. in the jobo tank.

Did you experienced bad/other results with two films on one reel?

..processing 2 120 rolls on 1 reel in a JOBO 1520 is no problem, you'll need the red tab divider though (only place for 1 reel in such a tank anyway.. ..).

The real problem in such a setting is if you have enough developer: for instance Kodak and JOBO advice at least 100 ml of stock of Xtol (for some films 150 ml, JOBO has put out a publication on this, not sure if it is still on their web side)

Since a JOBO CPE2 can handle upto 600ml you are safe with 2 120rolls, but with other more dilute developer you can run into trouble

Best,

Cor

Dietmar Wolf · May 9, 2007

Yes. Back to back.

Thanks.

AgX · May 9, 2007

diwolf,

some thoughts on this…

In some cases this could be twice as economic, on two fields:

1. you could process in a given tank/reel combination twice as many films in one run.

2. it could be more economic if you process on rare occasions only. If you had to resort to a two shot (C-41) developer and wanted to process two films:
-) you could process them in sequence and use all developer;
-) you could process them parallel the classic way (2 reels) and dilute the developer by 100% which most probably spoils its activity
-) you could use 2 reels and twice the amount of developer and loose the chance for a 2nd shot due to decay;
-) you could process them back to back on one reel in one run and finish all developer in one run.

problem 1: developing time prolongation
Obviously you must prolong, but not as much as given for the 2nd run when doing it in succession; to my understanding just halve of that prolongation.

problem 2: residue of process chemicals between the films or rims
Just let the films drop after washing in a bassin with running water.

problem 3: handling
Never done that, but I guess it would be more difficult getting two films loaded on the reel. Obviously the spacing of the rims is decicive.

problem 4: tricky developers
Some developers are said to produce artefacts if the film (a single film) is squeezed into the reels (chemical interaction with substances smeared out off the emulsion).

problem 5: patches of unprocessed (practically: unfixed) film on the edges
Could be, dependent of rim spacing. Just an esthetic issue, or concerning longevity?

Just some thoughts, rather guessing! Never done that. Perhaps I missed the subject.

Dietmar Wolf · May 10, 2007

Hm. I just thought with 2 films on one reel, agitation might be hampered?

AgX · May 10, 2007

What situation are you talking about?

(Two 60mm films in line after each other within one winding on one reel compared to two 35mm films each in one reel???)

Dietmar Wolf · May 10, 2007

The jobo tank has space of 470ml and one reel.

I can put on this particular reel one film or two films back to back.

AgX · May 10, 2007

As stated before I've never done this. But I don't see any agitation problems in general when processing two films back-to-back in one winding.

But I realized

problem 6:
Any sort of AH layer on the back. It would only make sense processing these films that way, if that dye would come off without problems in that washing basin.

AgX · May 10, 2007

I must correct myself:
In standard processing any curvatures of the film will be equidistant between windings.
In processing back-to-back those curvatures would be orientated against each other, if the emulsion side forms a convex curvature.
That could be a problem.

But how much curvature is there anyway?

Cor · May 10, 2007

And loading a JOBO reel with 2 films back to back will be quite a chalenge, do they fit? Perhaps you'll get them in half way, and than you get stuck?

And the idea to have 2 dangeling films hanging below the reel, potentially scratching each other...

I would buy a bigger tank, or process one after the another..

Best,

Cor

How many reels in a developing tank?

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