...
...I do presoak twice at 100F / 38.5C for 30-45 seconds.
...So, next the Blix for 10-12 minutes (I do it longer than Tetenal recommends 6 minutes). Wash and Stab.
I do presoak twice at 100F / 38.5C for 30-45 seconds.
I use 2% acetic acid stop bath.
After stop bath I take the tank to the bathroom and wash film for 3’ with jobo bubble washer at 100F / 38.5 C
So, next the Blix for 10-12 minutes (I do it longer than Tetenal recommends – 6 minutes).
Stop is pretty much essential if you want to process 120 format roll film with Tetenal's C-41 soup. Tetenal's C-41 instructions (page 7) explicitly recommend a stop bath, because it "increases process reliability when the bleach fix bath is reused several times". It is also well known, that BLIX runs to completion, and Photo Engineer has repeatedly stated that BLIX times should be extended for complete silver removal.Stop is also not indicated so is running the blix longer (for what reason?).
This may well be the issue: there is a good chance that 500ml in a rotary processor don't agitate all that well, and give worse results than the recommended 250ml.500ml in a 1520, is about twice the needed quantity, and may or may not cause various pattern issues (no way to tell with your specific procedure as it is so far departed from the baseline), and would also be a thing to check.
How is 120 roll film different then any other roll or sheet film as far as a stop bath is concerned?Stop is pretty much essential if you want to process 120 format roll film with Tetenal's C-41 soup
It is also well known, that BLIX runs to completion, and Photo Engineer has repeatedly stated that BLIX times should be extended for complete silver removal.
This may well be the issue: there is a good chance that 500ml in a rotary processor don't agitate all that well, and give worse results than the recommended 250ml.
C41 chemistry is designed for one shot use and so is the Jobo system. The stated 55-60 rolls per 5L is a number derived of single use/one shot (for the developer at least, even if the blix can be re used). How many more rolls do you get out of re use? at what cost, at what risk? The kit is plenty reliable when using as one shot, and as you have found becomes completely unpredictable when re using it or deviating from the base line.PS: Using C-41 process chemistry single shot is quite expensive and not necessary, and these kits are specifically formulated for reuse.
Beats me. But seven years of experience with Jobo tank development of C-41 film tells me that there is a difference between 135 and 120 roll film. Several reports about yellow streaks with Tetenal's C-41 soup and 120 formatroll film were contrasted by many success stories from people with 135 format film, just like here. The difference here in this thread is that lrji does use a stop bath and still gets odd patterns on his film.How is 120 roll film different then any other roll or sheet film as far as a stop bath is concerned?
The instructions say 250ml, and lrji used 500ml, so you can't blame him for using too little chemistry. Even if the results look to PE's eyes like a case of too little process chemistry, this situation here is not such a case.PE also said you did not have enough solution in the tank. Following the instructions would be better.
The kit's instructions specifically describe how to use this kit multi shot. This is especially relevant if one uses inversion development with 250 ml chemistry per 135 format roll.C41 chemistry is designed for one shot use and so is the Jobo system. The stated 55-60 rolls per 5L is a number derived of single use/one shot (for the developer at least, even if the blix can be re used). How many more rolls do you get out of re use? at what cost, at what risk? The kit is plenty reliable when using as one shot, and as you have found becomes completely unpredictable when re using it or deviating from the base line.
As the OP is using a Jobo CPE2 rotary processor then I fail to see how the agitation is inadequate per se. However as maybe others have said the 1520 needs only 240mls for rotation so the CPE2 may be struggling to turn 500mls properly. 500mls or 485 mls to be strictly accurate is only needed when it is inversion agitation.
On the matter of using the developer on a once and dump basis can CATLABs or anyone else explain how 5L or 5000mls does 55 -60 films. If the tank needs 240mls for rotation but that will do 2x120 or 2 x 135 films then doesn't this give 40 films maximum from 5L of developer or have I missed something?
OP, I'd cut your developer to 240mls, use the top speed on the processor and see if this makes a difference
Best of luck
pentaxuser
Following the kit instructions would be the first thing to try, in order to trouble shoot your problem.
As the OP is using a Jobo CPE2 rotary processor then I fail to see how the agitation is inadequate per se. However as maybe others have said the 1520 needs only 240mls for rotation so the CPE2 may be struggling to turn 500mls properly. 500mls or 485 mls to be strictly accurate is only needed when it is inversion agitation.
On the matter of using the developer on a once and dump basis can CATLABs or anyone else explain how 5L or 5000mls does 55 -60 films. If the tank needs 240mls for rotation but that will do 2x120 or 2 x 135 films then doesn't this give 40 films maximum from 5L of developer or have I missed something?
OP, I'd cut your developer to 240mls, use the top speed on the processor and see if this makes a difference
Best of luck
pentaxuser
That is most certainly not in the instructions.
This may well be the issue: there is a good chance that 500ml in a rotary processor don't agitate all that well, and give worse results than the recommended 250ml.
The rotation speed may be too low. Start with the "P" setting.
Try filling a cylindrical container to the very top and then cap it! Now try to agitate! There is no movement other than thermally induced movement and thus with too much solution, the agitation decreases gradually to zero as you approach the max the tank can take. With a rotary processor this is critical, but with hand agitation it is just a tad less critical.
Also, read the Rotary Processing Journal published by Jobo. It is a series of very helpful articles in pamphlet form and published by Jobo over the years to supplement the manual. It it, they recommend higher speeds for some processes.
PE
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