Jobo Paper Processing - How to Do it Clean??

sorange · Jan 24, 2007

I'm in the early stages of setting up my first darkroom, with a used Omega C700 with dichro head and Jobo CPA-2 processor. I've finally gotten some decent test prints for exposure/development times, but I'm still getting ugly artifacts on the prints.

Here's what I'm using:
-- Jobo CPA-2 with lift
-- Jobo 2830 drum
-- Dektol at 1:4 strength

I start with a 2 min. prewet and develop for about 1:20. I'm using Ilford Multigrade IV RC paper (5x7), inserted into the drum with emulsion side facing out toward the ribbed walls of the drum.

There are often splotchy white areas on the print or at best small white smudges - even though development seems to be fairly even over the rest of the print.

So what am I doing wrong? And for bonus points, how in the world do you fit four 5x7 sheets into the drum without them blocking each other? For double bonus points, why is Jobo's online manual so lacking in practical information about placing paper in the drums (among other things)??

Nick Zentena · Jan 24, 2007

Is the drum dry?

Just be careful putting the paper in. Pratice just like you would with film loading.

fschifano · Jan 24, 2007

I'm not sure that the problem is necessarily limited to problems with the Jobo drum unit. It might be that you had some fixer on your hands when you plucked the paper from its package. I've done it myself and wound up with artifacts similar to what you are describing here while tray processing my prints. Never touch dry paper if your hands are not clean and dry.

Rolleiflexible · Jan 24, 2007

I'm probably not the best qualified to answer this -- on occasion I will print 16x20 fiber prints in a Jobo 3063, and when I run postcards I will process them in Jobo 3006 tanks. You mention two things in your workflow that sound odd to me.

(1) I believe the emulsion should face in, toward the center of the tank, not out toward the ribs.

(2) I do not think it is advisable to presoak the paper.

Others might have other and better ideas for you.

Sanders

sorange · Jan 24, 2007

Drum is dry (at least enough to focus on bigger issues), hands are dry. All chemicals have been pre-mixed and poured into the ready-to-use graduates in the Jobo unit.

Sanders, thanks for suggesting I reverse which way the emulsion is facing. That makes a little more snse & I'll try it tonight. As for prewet, I thought this was recommended by Jobo and several well-known Jobo users?

grahamp · Jan 24, 2007

You must have the emulsion on the inside, otherwise the chemicals will not reach the emulsion evenly. A pre-rinse is probably not going to make much difference on RC paper, but it does help with fibre base.

Rolleiflexible · Jan 24, 2007

I have much more experience with film than with paper in Jobo tanks. With film, a presoak is useful for a couple of reasons. First, it helps remove antihalation dyes. Second, it gets into the emulsion and slows down the development a bit. Jobo says that if you presoak, you don't need to adjust your development times to compensate for the constant agitation. That has been my experience as well.

With prints, well, that's a different matter, and now I am speculating a bit from more limited knowledge, so take this paragraph FWIW. Unlike film, a well-exposed print should be completely processed out. If presoaking paper displaces the developer in the paper and emulsion, it might inhibit the development of the paper. At best that would lengthen processing time. At worst it might lead to uneven development.

If one is processing fiber paper, then there is another problem. Jobo tanks were not designed for fiber paper but many of us use them for fiber prints anyway. The longer you leave a fiber print wet inside the tank, the longer the print presses against the tank ribs, and the more likely that the print will have indentations where the ribs pressed into the paper. And, also, the more likely the paper will crumple into a wad by the end of the process.

Again, I am not an expert on this -- perhaps others can chime in.

Sanders.

Nick Zentena · Jan 24, 2007

sorange said:
Drum is dry (at least enough to focus on bigger issues), hands are dry.

As for prewet, I thought this was recommended by Jobo and several well-known Jobo users?

Oh the road to hell is paved with dry enough. Trust me dry enough is bone dry. Even small droplets of water will cause problems. I let my drums stand and then wipe them dry with a paper towel. Doesn't take long but saves pain.

I do a presoak with colour. It warms the paper and drum. Lets the paper soak up water so it doesn't soak up so much developer. I can't see it hurting with B&W.

Neal · Jan 24, 2007

Dear sorange,

May I suggest that you save the Jobo for big prints and use trays for 11x14 and smaller?

Neal Wydra

pentaxuser · Jan 24, 2007

As far as fitting 4 5x7 into the drum at once, I understand there are separators which fit into the grooves. I have a drum which takes 2 5 x7 at a time and my experience is that without the separators then sometimes the prints will stay separate and at other times they will overlap and be ruined.

My solution is to use one 8x10 sheet on to which I make two prints, covering the bottom half of the paper, at each exposure, making sure that when taking the paper out of the papersafe for the second neg, I have got the unexposed part on top.

It helps that I do borderless prints at 5x8. Then it's simply a matter of guillotining the processed print down the centre.

pentaxuser

dancqu · Jan 24, 2007

Neal said:
... use trays ... Neal Wydra

Or use A tray much the same way A tube
is used when rotory processing. If one has
the dark space for loading a tube then
there's room for A tray. Dan

sorange · Jan 25, 2007

Nick Zentena said:
Oh the road to hell is paved with dry enough.

I think this quote should be immortalized.

jeroldharter · Jan 25, 2007

I find that batch processing multiple prints is very efficient using the single tray method and latex gloves. I can process up to 8 11 x 14 prints at once in a single 12x16 tray with no staining or marring of the emulsion. Also, It is alot faster than dealing with Jobo drums.

What is the purpose of using the Jobo for 5x7 RC prints? Seems like the trays, especially single tray, would be easier.

sorange · Jan 25, 2007

Neal said:
May I suggest that you save the Jobo for big prints and use trays for 11x14 and smaller?

Neal (& Jerrold), I've only just started printing and am doing so in my garage at night, so not a proper darkroom. The Jobo means minimal chemistry & fumes, and one defined space for processing both film and paper. Right now, I'm focused on fine-tuning the Jobo process to see if I can get good quality prints that way. If the Jobo is a poor choice for print quality then I hope the good folks on this forum will speak up about its limitations. Either way, I appreciate all the good feedback, because it will inform my darkroom design moving forward.

And... 5x7 RC prints because while I'm trying to get my chemistry, development times, and correct use of the Jobo refined, why waste the good stuff? ; )

Best,
-- Scott

dancqu · Jan 26, 2007

jeroldharter said:
"I can process up to 8 11 x 14 prints at once in
a single 12x16 tray with no staining or marring of
the emulsion. Also, It is alot faster than dealing
with Jobo drums."

I've managed 6 8x10s at once using an 8x10 tray.
That was years ago. Three tray processing was then
the Only way. Last night I worked with 4 5x7s testing
for the solution volume needed. A half liter will likely do.
Do you use slower chemistry when working a few
at a time? Perhaps more dilute? Dan

Ole · Jan 26, 2007

So far I've only done film in my JOBO, not paper.

But I can assure you that four sheets of 5x7" paper or film will fit in the 2830 tank! Us the spacers already mentioned, emulsion away from the walls, and don't even try to put anything in a drum that's merely "dry enough"!

Petzi · Jan 26, 2007

The emulsion must face to the inside of the drum!

I see no reason for a prewet.

Nick Zentena · Jan 26, 2007

You don't need the spacers. They might not hurt but it doesn't take much effort to load four sheets. Just stick your hand in there and feel the ridges in the drum.

sorange · Jan 26, 2007

SUCCESS!

Thanks to the many informed comments here, I am pleased to report last night I finally made my first good prints in the Jobo! Yeah!

The main thing I was doing wrong was facing the emulsion outwards in the 2830 drum, when it should have been facing in. I did prewet the RC paper again, but I haven't yet experimented to see if this is a necessary step. Diluted the Dektol to 1:4 and I think that helps.

And I finally figured out that orienting the 5x7 paper correctly can fit 4 sheets. :rolleyes:

Now that's settled, I can get to work on the image which is why I'm doing this in the first place! Thanks to all for sharing your knowledge.

-- Scott

ajduran · Jan 27, 2007

For sure putting the emulsion towards the side of the Jobo drum will cause blotches regardless of paper type. I've had some problems with streaking on RC papers without using a 'presoak'. Even still I've had problems with streaking until increasing developing times to 2:00 - 2:30. I guess it takes a little time for the developer to displace the water in the emulsion.

Never had a problem with FB papers though, even w/o presoak.

ajduran · Jan 27, 2007

By the way, lately I've been using D-72 1:9 for 2:30 in the Jobo drum, one shot. Gives nearly identical contrast as 1:3 and saves a bit on developer. I use 200ml each time then toss.

dancqu · Jan 27, 2007

ajduran said:
By the way, lately I've been using D-72 1:9 for
2:30 in the Jobo drum, one shot. Gives nearly
identical contrast as 1:3 and saves a bit on
developer. I use 200ml each time then toss.

Nearly a duplicate of my method of using a single tray.
An 8x10 works well with 250ml. A Cesco flat bottom tray
helps keep solution volume minimal. Stop is not used as
the one-shot very dilute fixer has not any carry over
build up. What carry over, what with such
very dilute developers? Dan

sorange · Jan 27, 2007

FWIW, I'm using only about 160ml of the Dektol per shot, at the 1:4 dilution. The Jobo 2830 drum needs only 100ml of chemistry, but I was erring on the side of caution while trying to get the process down.

Jobo Paper Processing - How to Do it Clean??

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