Getting ready to do E6 processing with a Jobo expert drum...

[Vaughn]

I use 50 rpm with expert drums for color, per Jobo’s recommendation.

Regarding opening the tanks with air, if you fill the tank to the top it creates a very low drama lift instead of pop with the foot pump. I wouldn’t use compressed air given the cost of the expert drums.

Have you counted the number of revolutions per minute? I am curious if the 50 rpm setting actually turns a drum the diameter of a 3005 Expert drum that fast.

[Larry Gebhardt]

Have you counted the number of revolutions per minute? I am curious if the 50 rpm setting actually turns a drum the diameter of a 3005 Expert drum that fast.

I have not measured it, but next time I process some film I'll try. My ATL 2000 has 25, 50, and 75 RPM options. My perception is they are probably close to that, with the 50 RPM feeling twice as fast as the 25 RPM. Part of the problem with measuring it will be that the drum reverses every turn or two, so the rotation speed is not constant. What ever it's doing is working since the film comes out nice and even, including at the slow speed which I use for black and white.

[Steven Ruttenberg]

Fill the Expert drum all the way to the top with water. Then top removal with the pump is no big deal. The top just lifts up smoothly. Just press down on the pump with your hand, takes very little force.
The water will overflow out of the tank when the lid comes off, so do this in the sink.

I like that idea!

[Steven Ruttenberg]

I found when doing E4 and later E6 the color developer goes to completion and I could extend the time and get richer looking color. My hand developed slides always looked better than the ones I sent out to be machine processed. This should cover your question about diluting the color developer. Your apparent overexposure might be from the color developer being underdone. As the first developer is the critical one it should never be diluted more, timing is critical there unless you are pushing the film.

I believe the developer was good. I processed 40 sheets and many were exposed normally which leads me to believe I need to modify how I am metering in the field for slide film

[Steven Ruttenberg]

Have you counted the number of revolutions per minute? I am curious if the 50 rpm setting actually turns a drum the diameter of a 3005 Expert drum that fast.

I have not. I use it on oscillate so it kinda doesn't matter? I use an after market rotary machine. Works pretty slick. I have two of them so I can set one up while the other is doing its thing. Could use two more.

[Steven Ruttenberg]

I think for really critical work, ie, the ones you just cant f up, I will hand process in a tray regardless of film type. I have processed 60 sheets of 4x5 now in the jobo and have about an 11% failure rate in that the development was uneven or streaky, what appears to have been airbubbles stuck to the film, stupid stuff like that. I may have to rap the tank on counter harder.

[Tin Can]

Keep it simple

I had a hard time learning Sheet

I made my entire system as mindless as I could

Then never changed anything

and I won't

[Duolab123]

Nothing magical about processing sheets of E6, other than the price of film. The expert tanks are splendid when teamed with a Jobo CPP processor. I can't afford much 4x5 Ektachrome, beautiful stuff though.
First developer times and temperature are ultra-critical. I would run a test before committing precious frames.

[Vaughn]

I have not. I use it on oscillate so it kinda doesn't matter? I use an after market rotary machine. Works pretty slick. I have two of them so I can set one up while the other is doing its thing. Could use two more.

No, it does not matter...I was just wondering what the actual drum rpm would be, compared to the setting used on the Jobos.

On motor bases such as the Unicolor or Beseler, the motor speed is constant and the diameter of the drum/tube will determine actual rpm. The diameter of the Expert Drum 30xx series is about 8 inches and it takes awhile for the wheels of the motor base to turn that 25 inches of circumference. If the Jobo processors spin the drums on their axis, then the rpm would be consistent over different diameter drums and tubes at the same setting, I'm guessing.

I am just trying to imagine a 3005 drum rotating over three times the speed of mine (my 15 rpm vs Jobo's 50 rpm)...

[Mal Paso]

Wow! I never tried a drum. I built a 1 gallon water jacketed E6 batch line from welded ABS sheet and surplus Kreonite parts. I would turn it on in the morning and process when I got back from the shoot. It would process 20 4x5s at a time and you could replenish. Is this One Shot use of the chemistry?