CombiPlan and R5 Monobath in lit room, best practices.

[Lenrick]

I have now developed a few sheets of Atomic-X film in R5 Monobath using a CombiPlan tank. Here are some thought if anyone else is thinking of doing the same (or something similar). I’m sure there are better ways of doing some of the things that I suggest, and perhaps a few steps can be eliminated.

One should note that the New55 Company has recommendations on how to best use their monobaths. One such recommendation is “In darkness, quickly immerse the exposed black & white film in the [monobath]...” I have no way of following this recommendation and must find a route which works in lit rooms.

One recommendation that I try to follow, however, is the following: “Avoid pouring the warmed monobath into a cold tank; streaks may result from temperature differentials and turbulence.”

My recommendations:
1) Do not develop 6 negatives in a single run, but a maximum of 4. The 2 inner slots must be occupied by film in order to protect the outer 4 negatives from pouring liquid. Make sure the emulsion on your 4 negatives are aligned to face the walls of the tank.

2) Make sure the tank is at the desired temperature (24C / 75F) by letting the tank float on water with that temperature before adding the monobath (do not forget to flip the tank to make sure both sides are at the desired temperature).

3) Add the liquid through the side-port so that the air can escape through the lid-port. Find the optimal angle for the tank, since horizontal position is not recommended. In horizontal position the liquid will go directly onto the negatives, plus you need more than 1 l of liquid for horizontal position. At the optimal angle, the 1l-bottle from the New55 web store is enough.


In the figure below you can see some of the artifact that can be avoided using these instructions.

[Lenrick]

In the figure below you can see an image developed using these instructions.

[Bob Salomon]

Take the top off your tank and look at the top edge of the tank, see the trough on the top? Now look at the bottom end of the Light Tight Hose Connector. See the opening for the chemistry?
When you fill from the top the chemistry goes through that opening and into the trough where it then runs down the side of the tank and not directly onto the film.
When you fill from the side the chemistry will run down the film.

[Lenrick]

Yes, you are right. But it takes too long time to fill the tank the way it was intended. Much much too long time, for my taste. The air does not escape fast enough.

Filling from the side port when the tank is angeled works better, I think.

[Bob Salomon]

Yes, you are right. But it takes too long time to fill the tank the way it was intended. Much much too long time, for my taste. The air does not escape fast enough.

Filling from the side port when the tank is angeled works better, I think.

Do you open an air path by giving the Light Tight Connector a half turn before filling?

[Lenrick]

Yes, yes I do...or did rather. I stopped filling the tank that way a long time ago, since I thought it took too long.

But to be fair, I have never measured the time it takes to fill the tank through the lid-port (with the port turned to "open"). I'll time myself soon, and compare that to filling the tank through the side-port (with the tank at an angle so that the liquid do no run over the negatives).

Maybe I'm simply biased, some solid numbers should be helpful.

[Bob Salomon]

Yes, yes I do...or did rather. I stopped filling the tank that way a long time ago, since I thought it took too long.

But to be fair, I have never measured the time it takes to fill the tank through the lid-port (with the port turned to "open"). I'll time myself soon, and compare that to filling the tank through the side-port (with the tank at an angle so that the liquid do no run over the negatives).

Maybe I'm simply biased, some solid numbers should be helpful.

You should find that the fill through the top and empty through the bottom times are the same as long as you open the air path on the top each time.

[scheinfluger_77]

I have had good luck on the Combi's by filling via a funnel connected to a vinal hose connected to the bottom port, with the tank in its upright position. Still takes about 30 seconds to fill but until I started doing this I would get random flow marks on the film. I was not using a monobath.

[Lenrick]

Interesting solution, Scheinfluger_77. Thanks for the tip.

How do you remove the hose in order to plug the port when the tank is full? Without causing a huge mess, I mean, assuming the hose is also full of liquid when you remove it. Or du you simply plug the hose when you agitate?

From my experience, the R5 Monobath is not forgiving to work with. But I would recommend everyone to try it because it is fun and will probably help you find "hidden" flaws in your current routine.

[scheinfluger_77]

Simple. I tip it over on its back, remove the hose, cap the hole, and go back to upright position. Yes there is a little bit of chem slosh but better that than processing marks in my view.