Jobo 2550 Tank + "Color by Beseler" Motor Base

[KraftwerkNation63]

Hello Everybody,

I'm Théo from France. I'm 24 years old, and i begin to shoot with an US Camera. A Speed Graphic Graflex 4x5.

I'm at the step of the processing. But i have a lot of question about the system of the Beseler Base. I explain.

I use "Microphen" developer, on the explanation of this developer, it is written : "For rotary tank with continuous agitation and no presoaking, reduce above development by 15%". I found this sentence a little blurry. Because, all rotary system have not the same speed and other settings can change. I have a rotary base "Color by Beseler" with no reverse system.

I have make a simulation. I have put the two 2509n spire in my 2550 tank + 600ml of water. I have use my chronometer and my Jobo Tank make 40 revolution per minute.

So, i'm a little confusing about 2 things:

First: At which % i must adjust my developing time, with all this information? (I know for exemple that a CPE2, works at 30rpm in "speed 1" and 75rpm in "speed 2")

Second: I have seen a lot of person on many page of this forum who say that they don't change the sense of the Jobo tank during the rotation in unic direction. And a other person change the position of the tank... So: "Who is right?"

Thanks to help me

[diversey]

1) For rotary tank with continuous agitation, reduce development time by 15% compared to inversion film development, for example, inversion development is 10 min, your start rotary development time will be 8.5 min. Use 30 rpm, speed 1.
2) 30rpm in "speed 1" and 75rpm in "speed 2": 30rpm speed 1 is for film development; 75rpm speed 2 is for print development.
3) Unidirection or reverse direction: make sure your tank can have one full rotation in each direction when you use reverse motor base, or you need convert your motor base to unidirectional.

[koraks]

Rotation speed doesn't really matter for development time. It's continuous agitation and that's what counts.
Uou may find you get uneven development at certain speeds; some find better results at high speeds, some at low speeds.

[Jim Noel]

That information is for a Jobo processor.
I use both a Jobo and a smaller base like the one you have.
It is very easy to get carried away with minute details when processing. Simplify the process, especially in the beginning.
Don't worry about the speed of your base. I suggest you start by developing 1 or 2 negatives in the rotating tank for your regular tray time and 1 or 2 for 10-15% less. Print these and decide which works best to give you the kind of print you prefer.

[KraftwerkNation63]

1) For rotary tank with continuous agitation, reduce development time by 15% compared to inversion film development, for example, inversion development is 10 min, your start rotary development time will be 8.5 min. Use 30 rpm, speed 1.
2) 30rpm in "speed 1" and 75rpm in "speed 2": 30rpm speed 1 is for film development; 75rpm speed 2 is for print development.
3) Unidirection or reverse direction: make sure your tank can have one full rotation in each direction when you use reverse motor base, or you need convert your motor base to unidirectional.

Thanks Diversey. My Beseler base is unidirectional.

[KraftwerkNation63]

Rotation speed doesn't really matter for development time. It's continuous agitation and that's what counts.
Uou may find you get uneven development at certain speeds; some find better results at high speeds, some at low speeds.

In fact, i have heard that. Some people prefer low speed and other high speed...!

[KraftwerkNation63]

That information is for a Jobo processor.
I use both a Jobo and a smaller base like the one you have.
It is very easy to get carried away with minute details when processing. Simplify the process, especially in the beginning.
Don't worry about the speed of your base. I suggest you start by developing 1 or 2 negatives in the rotating tank for your regular tray time and 1 or 2 for 10-15% less. Print these and decide which works best to give you the kind of print you prefer.

Thanks for your help Jim! I have only a Beseler base

I have put the Jobo speed to compare with my base... And for the sens of the tank i must change it during the process? Or do you think it is not useful?

[koraks]

You'll have to see how it goes with the tank rotation in one direction all the time. You may or may not get uneven development. If you get bands of unevenness, you know what the possible cause would be.

[KraftwerkNation63]

You'll have to see how it goes with the tank rotation in one direction all the time. You may or may not get uneven development. If you get bands of unevenness, you know what the possible cause would be.

Thanks. So i will try with 15%