Jobo 2800 Series & Film Development

[photoevangelist]

This thread is for those of us who are stubborn enough to go against Jobo's warnings.

There doesn't seem to be a dedicated thread to this topic and information seems to be scattered everywhere, though there seems to be a good bit of interest in the subject. In this thread, post your experiences (success and failure) with developing film in the 2800 series print drums. It's my hope that we can learn from each others experiences and help others that are interested in using this mix.

[photoevangelist]

FP4 / D-76 1:1 20 degrees C / 500 ml chemistry in bottom half of Jobo 2850 with CPP-2 on F setting / 5 min Pre-Wash, 11 min development
* I used photoshop to bring the levels over to show the inconsistency better.

(I've since read another thread that D-76 should be used 1:2 or 1:3 in these print drums)

[photoevangelist]

HP5+ / D-76 1:1 20 degrees C / 500 ml chemistry in bottom half of Jobo 2850 with CPP-2 on F setting / 5 min Pre-Wash, 11 min development

* I used photoshop to bring the levels over to show the inconsistency better.

(I've since read another thread that D-76 should be used 1:2 or 1:3 in these print drums)

[djhopscotch]

Looking like you have flow lines in the sky, i had similar problems with the 2500 series with reels. I use a uni color non-reversing motor base. I started manually reversing the drum every 20s and it has seem to solve the flow line problems. Can you set the cpp-2 to either reverse direction more or change to a faster speed?

[photoevangelist]

Looking like you have flow lines in the sky, i had similar problems with the 2500 series with reels. I use a uni color non-reversing motor base. I started manually reversing the drum every 20s and it has seem to solve the flow line problems. Can you set the cpp-2 to either reverse direction more or change to a faster speed?

I'm on the lowest setting, which is F for film. Yes, faster speeds are available, six total. 0 = off, F, then 3,4 next P for print, then 6, 7.

[Sal Santamaura]

...CPP-2 on F setting...

...CPP-2 on F setting...

I'm on the lowest setting, which is F for film...

That doesn't reveal actual drum rpm unless you also factor in the processor's serial number and any upgrades that were incorporated into it:

http://www.largeformatphotography.in...l=1#post836600

[photoevangelist]

That doesn't reveal actual drum rpm unless you also factor in the processor's serial number and any upgrades that were incorporated into it:

http://www.largeformatphotography.in...l=1#post836600

Thanks for the information Sal! It must be 25 rpm. This is the older model without the upgrade.

[photoevangelist]

Okay here's another test using Rodinal 1:50. Got some uneven development in the sky again.



HP5+ / Rodinal 1:50 20 degrees C / 500 ml chemistry in bottom half of Jobo 2850 with CPP-2 on 25 rpm / 5 min Pre-Wash, 11 min development

* I used photoshop to bring the levels over to show the inconsistency better.

[photoevangelist]

This image was developed with the same image from above.



HP5+ / Rodinal 1:50 20 degrees C / 500 ml chemistry in bottom half of Jobo 2850 with CPP-2 on 25 rpm / 5 min Pre-Wash, 11 min development

[Sal Santamaura]

...It must be 25 rpm. This is the older model without the upgrade.

Your next trial should use a speed setting of 3-1/2 to achieve around 45 rpm.

Okay here's another test using Rodinal 1:50. Got some uneven development in the sky again....25 rpm...

Even at the correct speed, you'll probably still not achieve even results you're seeking. Expert drums were created for a reason. Note that the chambers in them aren't cylindrical. They're fat-waisted (reverse hourglass), made from sheet stock bent to the desired shape and glued together.

Sometimes it's best to stop being stubborn and heed the manufacturer's advice.