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3 Roll Developing Tank: Good Idea?

A 4-roll Kindermann SS tank serves me well. I have recently added two Jobo tanks, a 1520 and a larger one (the number escapes me, still on its way to me) for LF development.
 

There was a discussion about this on some other thread a while back, about the minimum amount of rodinal to use per roll. Some datasheets said 10ml/film, some 5ml/film. Personally, I've done 3ml + 300ml for a roll of 35mm with no ill effects, but it really depends on what you've shot on the film, lots of light or lots of dark as to how much gets used up. Stick with at least 5ml/roll and you should be fine, 10ml if you're paranoid.
 

Using less than the standard will still produce a film that is developed, but it will not give you absolute consistency from one film to the next. What that means in practice is different things to different people. I prefer consistency, and home-made Rodinal is incredibly cheap so I do not even bother to skimp on developer. By comparison a film is much more expensive. Even commercial Rodinal is cheap enough to not justify skimping on developer for the sake of saving a few bucks. I have found 6 ml to be around the ideal quantity as it gives me 300 ml at 1:50. For 120 film I make up 600 ml with 12 ml concentrate, and develop either one or two rolls in a single paterson reel. If I were to do stand development at 1:100, I'd make up 600 ml from 6 ml concentrate, and even for a single 35 mm I'd use the entire volume in a taller tank with an empty spacer reel.

Of course, others need not be as paranoid as I am. Everyone should do tests to see what works for him/her.
 
My largest daylight tank holds six 120 or 220 reels. When I've had a lot of film to run, it's been a big time saver. There's no reason not to use larger tanks as far as I can see, and processing in larger batches gives you more consistency from one roll to the next. With the large daylight tank, I usually pour in the developer in the dark with the lid off and lower the reels in on a rod, but then continue with the lid on and the lights on, and I don't have any uneven development issues.
 

For my equipment it certainly IS true. I don't get anywhere near 8-10 cm between films. If two 120's are loaded edge-to-edge in a Paterson reel, then the tip of the outer film barely manages to squeeze inside the ball bearing. It is a very tight fit. Rotary agitation causes the film to slide more easily in the grooves, and allows the two films to overlap. It is not only a development problem, but also for the sake of proper washing. I had a case where the films overlapped after I rotated the spool during fixing. Subsequently I could not get the fixer washed out properly. I had to take the films out while wet, rinse them while handholding, then dry and respool them to be sure I got all the fixer out. I was very annoyed with myself, but I learnt the lesson. I would have fewer qualms about multi-reel developing if I did very frequent developing. But since my chemicals tend to stand for a month or two, sometimes longer, in between developing sessions, I feel that my risk is best spread by handling smaller batches.
 

You should get 2 test rolls and load them in the light to see how this works. There is room on the reel for a 220 roll + plenty of margin, thus there is also room for 2X120 + some space in between. There might be less then 8cm, but plenty of space, still.

Two comments about paterson - the twirl agitation (which is not rotation) went out when cars had fins, and - ball bearings on the reels are a real impediment when loading non perforated film.

If you want to rotate, rotate the entire tank, otherwise, inversion is probably better then the twirl stick (and will help keep films in the same place you left them when loading).
Jobo reels, do not have any of the above mention problems (with or with out the use of the duo clip), the tanks use less chemistry and they do not leak.

All that said, stick with what works for you, or upgrade if you want more capacity with less worry.
 
Reinhold said:
If your room is dark enough to load the reels, it's dark enough to develop using clear acrylic tanks that you can make yourself...

Reinhold
Click to expand...

To add to my post #9 about using clear dip & dunk tanks in the darkroom; good re-mixing of the chemistry during agitation is important to prevent stratification in a fluid column.
To prevent it, I punch holes in a plastic can lid and put it at the bottom of the reels.
With each lift the fluid column is totally re-mixed, completely eliminating the possibility of "bromide drag" (a source of uneven development).

Reinhold
www.re-inventedPhotoEquip.com
 

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