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View Full Version : Jobo Expert drums: do the chems get the back?



Nicolai Morrisson
1-Nov-2007, 14:36
I'm just getting started in 8x10 and don't have darkroom access, so I'm looking at the Jobo Expert drums. Does the chemistry get to the back of the sheet, or is the film pressed tightly enough against the inside of the tubes that none gets there?

I once tried processing 4x5 back-to-back, and while the emulsion side developed without issue, the backs stuck together, didn't let chemistry in, and I had to wash the anti-halation dye out at the end. I'm wondering if I'm going to have the same problem with the Jobo.

Thanks!

Shailendra
1-Nov-2007, 14:56
I just got into 8x10 photography and processed my first few rolls on a Jobo 3005 tank. I had consistent processing but used about 10% more fluid than suggested. I think you should have no problems with the Jobo Expert Drums.

Ron Marshall
1-Nov-2007, 15:19
It does get to the back. The Jobo is a good design and can easily and consistently be hand-rolled.

SamReeves
1-Nov-2007, 15:54
Agreed. Really excellent, but I add 20% more just to be on the safe side. Should a catastrophic life problem happen. ;)

Oren Grad
1-Nov-2007, 16:17
The chemistry does get to the back. I was told once by a Jobo rep that the wells aren't simple cylinders, but have a subtle barrel shape that facilitates circulation. I've never tried verifying that, but I've used Expert drums for many processing runs on a CPA-2 over 10 years, and the film bases have cleared perfectly every time.

Deane Johnson
1-Nov-2007, 17:09
Why does the chemistry need to get to the back?

Jan Pedersen
1-Nov-2007, 17:20
The fixer need to get to the back to clear the negative and that is a constant problem for me. I have used 50% more chemistry than called fore but still need to clear the film in a tray. Not that exited about the Expert drum (3005).

tim atherton
1-Nov-2007, 17:24
The fixer need to get to the back to clear the negative and that is a constant problem for me. I have used 50% more chemistry than called fore but still need to clear the film in a tray. Not that exited about the Expert drum (3005).

8x10 or 5x7 in the Expert Drum?

I've never had to re-fix any of the hundreds of sheets of film I've processed beyond what happens in the drum.

I'm trying to imagine what you must be doing wrong?

Deane Johnson
1-Nov-2007, 17:26
The reason I asked is that I used to use some Calumet plastic sheet film holders that held the film firmly against the plastic. Their indication was that there is no need for the back to receive chemicals as all of the action is in the emulsion. The back is nothing but the estar or whatever the base is made of.

It puzzles me that you need fixer to the back to clear the film. I'm not saying you're wrong, it's just something I never realized.

Jan Pedersen
1-Nov-2007, 17:26
Tim, it is the same problem wheter i dev 5x7 or 8x10
I presoak for 5 minutes but still have antihaltion dyes in spots and ocationally spots not completely fixed to.

Robert A. Zeichner
1-Nov-2007, 17:28
I have several drums of this type and most times, it is not a problem. Occasionally I'll have to clear a neg that has some residual dye stains. I prepare a small tray with fixer and a couple of minutes in that solution takes care of the problem. I then wash for a minute, hypo clear again and wash in my Gravity Works washer hanging in Kodak #4 5x7 hangers. A bit of a nuisance, but considering the consistancy of the develpoment possible with the Jobo system, it's a small price to pay.

SAShruby
1-Nov-2007, 17:30
Tim, it is the same problem wheter i dev 5x7 or 8x10
I presoak for 5 minutes but still have antihaltion dyes in spots and ocationally spots not completely fixed to.


Is the machine is properly leveled? What speed do you set? If table is not leveled, it might cause those problems.

Jan Pedersen
1-Nov-2007, 17:35
Peter, it is level at least within narrow tollerances. It is running on a Beseler motor base in one direction and would run of if not level.

Nicolai Morrisson
1-Nov-2007, 17:50
Thanks for all the replies! Every once in a while is OK, I just don't want to be double-fixing every last sheet. I wasn't planning on using T-MAX anyway. :)

tim atherton
1-Nov-2007, 17:51
It is running on a Beseler motor base in one direction and would run of if not level.

that could well be part of the problem

Have you tried reversing the drum several times during processing? (or introducing an "irregularity" on one of the roller wheels...?)

Jan Pedersen
1-Nov-2007, 18:09
The drum can unfortunately only run in one direction but i will flip the drum 180 degree next time i develop (Tomorrow) Just completing a couple of test sheets of TMY and again blue dye in a couple of spots after 20 minutes of rinse. No fixing problems this time though.
Is it possible that the Beseler is running to fast? I have a Unicolor motor base which is quite a bit slower than the Beseler. Did not try it casue it feels a little rinky dinky compared to the Beseler.

Deane Johnson
1-Nov-2007, 18:31
Tim:

I love your Immersive Landscapes. What an original idea, and what a great series.

Deane

tim atherton
1-Nov-2007, 18:35
Tim:

I love your Immersive Landscapes. What an original idea, and what a great series.

Deane

thanks... it's sort of incomplete and been left up in the air for a while.

I have a bunch more to scan, and also a whole lot of ideas for looking at the southern (where I am now) rather than the northern edge (where I was) of the Boreal forest and how it intersects with the city among other things

tim atherton
1-Nov-2007, 18:36
The drum can unfortunately only run in one direction but i will flip the drum 180 degree next time i develop (Tomorrow) Just completing a couple of test sheets of TMY and again blue dye in a couple of spots after 20 minutes of rinse. No fixing problems this time though.
Is it possible that the Beseler is running to fast? I have a Unicolor motor base which is quite a bit slower than the Beseler. Did not try it casue it feels a little rinky dinky compared to the Beseler.

Try the Unicolour and see if it makes a difference - I used one for quite a while with the same drum just fine (until I got an actual Jobo)

Brian Ellis
1-Nov-2007, 18:40
The fixer need to get to the back to clear the negative and that is a constant problem for me. I have used 50% more chemistry than called fore but still need to clear the film in a tray. Not that exited about the Expert drum (3005).

Deane Johnson
1-Nov-2007, 18:43
thanks... it's sort of incomplete and been left up in the air for a while.

I have a bunch more to scan, and also a whole lot of ideas for looking at the southern (where I am now) rather than the northern edge (where I was) of the Boreal forest and how it intersects with the city among other things

It's something that works best as a series, as you have presented it. It's very difficult to present meaningful images of this type subject matter, but the series approach really makes the images feed each other.

Jan Pedersen
1-Nov-2007, 18:53
Quote:
Originally Posted by Jan L Pedersen
The fixer need to get to the back to clear the negative and that is a constant problem for me. I have used 50% more chemistry than called fore but still need to clear the film in a tray. Not that exited about the Expert drum (3005).

__________________
Brian Ellis
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Last edited by Brian Ellis : Today at 18:44. Reason: Have no idea why it was posted



Have no idea why this was posted either!

Brian Ellis
2-Nov-2007, 12:00
Have no idea why this was posted either!

I didn't realize anyone would care enough to respond but if you must know, I planned a response and then decided not to send it so I erased my response but apparently inadvertantly hit the "submit" key.

Songyun
2-Nov-2007, 12:31
What model from unicolor would you recommend for 3010 and 3005? These drum are huge, I just got mine today.

Vaughn
2-Nov-2007, 12:33
The fixer need to get to the back to clear the negative and that is a constant problem for me. I have used 50% more chemistry than called fore but still need to clear the film in a tray. Not that exited about the Expert drum (3005).

I had similar problems with 8x10 FP4+ in the 3005. With some help from a Ilford QC-type person, we nailed it down to using a fixer with a hardener (Kodak Rapid Fix).

The last two batches of negs through the 3005 using Ilford Rapid Fixer (w/ no hardener) have yielded great results (with no out-of-the-drum fixing tray). Film can also have a gelatin layer on the back to counter the gelatin on the emulsion side -- to reduce the curling of the film when dry. My pet theory is that the gelatin on the back would get hardened by the fixer and would not totally release the anti-halation layer...I would actually end up with some white gunk (salts of some kind) left on the back of the film when dried.

When I run out of the Ilford Rapid Fixer, I will try some Kodak Rapid Fixer, but I will leave out the hardener.

Vaughn

Jan Pedersen
2-Nov-2007, 14:53
Vaughn, good to hear about your experience. I usually use the Zonal Pro EC Rapid Fixer but last week bought some TF4 from Formulary. No difference seen yet.
Will in a few minutes try the Unicolor base to see if a slower rotation speed will improve anything.
The Film i have developed with same results are TMY, TXP, Delta 100, Fomapan 200 and Classic 200

Vaughn
2-Nov-2007, 20:06
Good luck, Jan. These things can be very very frustrating.

I also do a pre-soak for 10 minutes -- most of the antihalation layer comes off with the presoak...at least with Ilford films.

Vaughn

Jan Pedersen
2-Nov-2007, 20:13
Well, Something points to the rotating speed of the Beseler base.
My last run of Delta 100 came out fine, only variable changed was the motor base.
The Unicolor is about half the speed of the Beseler so will stick to that one and see if i can get a good relationship with the Expert drum going.

Have never presoaked for 10 minutes but will try should the problem come back.
Thanks for the tip Vaughn.

jan

Vaughn
3-Nov-2007, 15:40
My ten-minute pre-soak is perhaps a bit towards excessiveness.

Great to hear about your success with the Unicolor base. Did you check on the wind speed outside? I swear that there are variables that affect our processes that we just don't know about!:eek:

Vaughn

PS...I am using about 500ml of fixer. I use a liter of water for the pre-soak, changed once during the pre-soak...probably do not need to change the water, but I am just standing there anyway. It gives me a feeling that I am actually doing something!