Jobo - Uneven developing

Light, film, exposure..
smbooth
Posts: 405
Joined: 29 Jul 2012, 00:20

Jobo - Uneven developing

Postby smbooth » 31 Aug 2014, 12:47

Have anybody experienced these kind of development fault when using a Jobo 2500 series tank. I haven't been using one until recently and although this is the first time its happened on 810 sheet i like to know if it not unusual to see.
I'm assuming its from the developer washing around the little film clips that slide over the drum ridges, the sheets i developed following I didn't use them and the sheets developed fine. But that said I have not have it happen on 45 / 57 or other 810 sheets.
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Lachlan717
Posts: 494
Joined: 03 Aug 2012, 16:49

Re: Jobo - Uneven developing

Postby Lachlan717 » 31 Aug 2014, 15:20

Shane,

Looks like some form of disruption to the initial developer flow, although the linear nature of the pattern would seem counterintuitive given the drum was rolling...

Did you do a prewash?

jamespierce
Posts: 22
Joined: 15 Jul 2013, 18:16

Re: Jobo - Uneven developing

Postby jamespierce » 01 Sep 2014, 09:44

Are you doing the 8x10 as if it's a sheet of paper print drum style ? Or do you have the cat labs 8x10 film spiral for these tanks ?

smbooth
Posts: 405
Joined: 29 Jul 2012, 00:20

Jobo - Uneven developing

Postby smbooth » 01 Sep 2014, 19:48

Lachlan: with the drum it stands upright and the developer get pour in to the top which then flows down the tube into the bottom of the drum making no contact with the film until its turn on it side when put onto the drive magnet. At that point the developer flow 90 degree to the marks for a short time before the drum starts to rotate in the same direction of the marks. I don't prewash.

James: the tank is a 2800 series jobo but the print drum cup has been replaced with a funnel and centre tube which I think turns it into a 2500 series. I don't know if the inner make-up of the drums are different, I don't think so. Mine has ridges about 2mm and spaced about 20 mm apart, then there are 4 bigger ridges which fit 8 inch wide film, or using the other ridges fit 7 inch. On to the ridge you can fit a small split tube which traps the film in place but it seems to stay in place without them as well.. In short I'm using it like a paper developer tank. I didn't know you could get a 810 spiral like the 45 one.

jamespierce
Posts: 22
Joined: 15 Jul 2013, 18:16

Re: Jobo - Uneven developing

Postby jamespierce » 02 Sep 2014, 17:13

Right - I tried that early on and couldn't ever get consistent results I was happy with... Found it a bugger to get the film to clear well etc. I haven't tired one, but if I didn't have my big expert drums I'd try this...

http://www.catlabs.info/product/catlabs ... ssing-reel

Looks a bit fiddly to load, but for occasional use it would be fine.

Lachlan717
Posts: 494
Joined: 03 Aug 2012, 16:49

Re: Jobo - Uneven developing

Postby Lachlan717 » 02 Sep 2014, 17:55

I do my 7x17 in 2XXX drums. I just slide the film in between these ridges that you mention. I've got clips but have never used/felt the need to use them.

Never had a issue doing it that way. Never had film slip out, or weird development.

I leave the film clear of the bottom of the drum (25mm+) and run it on a lift Jobo at slowest speed.

Of course, YKMMV...

smbooth
Posts: 405
Joined: 29 Jul 2012, 00:20

Re: Jobo - Uneven developing

Postby smbooth » 02 Sep 2014, 19:01

Lachlan, I didn't have any issue when the clips were removed, might be standard practice now.

James, I have seen these, but a bit like you I think they look fiddle to use.

Warmtone
Posts: 50
Joined: 30 Sep 2012, 21:03
Location: Melbourne

Re: Jobo - Uneven developing

Postby Warmtone » 10 Sep 2014, 08:59

I use the Jobo CPP2 and various Jobo drums including an expert drum for 5x7 negs
To some extent unevenness depends on the developer you using and also the type of tank.
Some developers are harder to work with than others eg pyro which I think works better in a tray.

A pre soak is a good idea and promotes even take up of the developer. Secondly I think unevenness can be due to standing wave patterns in the developer due to the repeated pattern of the rotation process. Ideally you want random flow of the developer Another factor for processors is the speed of rotation which needs to be kept slow. I wished the CPP2 would rotate more slowly. Some people suggest periodically removing the tank to invert it and break up any regular flow patterns .

The Jobo Exert drums are excellent but expensive I bought mine used.
I am about to try Ilford DDX in the Jobo CPP2 with FP4 and will let you know how it goes.


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