I've been trying to get some RA4 working here but haven't had any luck. I came back and read this forum many times, but still getting cian/green streaks and general cian/green fog, total lack of contrast.
Let me tell you what I have and what I have done so far:
No, I don't have a safelight of any kind.
Yes, it is completely dark in my darkroom. The entire processor is in the dark.
There is no outside, there is no light coming in.
I used so far 5 different papers, different batches, different sources.
Colette processor from Colex - but with no temperature control, running at 24C.
I used the Display speed, 115sec dev time, all pumps are fine
•changed the tanks order, added a stop bath between Dev and Blix (no change)
proceeded to try my old faithful
Nova slot processor - temp control, running at 35.5C
45s dev time
•mixed nem chemistry RA4 RT
•tried 29C, 32C, 38C also (no change)
•added prewet (no change)
•added stop bath (acetic) (no change)
•cut dev time to 30s (a bit of improvement)
•almost doubled Blix concentration (a bit of improvement in contrast)
Is there a chance that even with a stop bath, the blix is acting too slow and allowing the cian fog/streaks to form?
I'll try post some images on my blog: http://refotografia.wordpress.com/
Any input or ideas with be appreciated.
Cyan stain or coloration in streaks indicate that the developer was contaminated with blix or fix, that the stop was not good enough or complete enough, or that the lights were turned on before blixing was complete. I have never generated cyan stains by other means. Diffuse cyan streaks may indicate red light fog.
I'll wait to see a sample.
•the chemistry came in with typical coloration, and both times it was mixed I am sure I didn't mix anything I shouldn't.
•IIRC I added 120ml of Glacial Acetic Acid to 9 liters of water to make the stop bath used in the Colette, the other one was my regular B&W stop that was ready at the time. I'll try a newer Glacial Acetic Acid package, just to be sure, if I try developing again @24C, but @38C this shouldn't even be an issue, correct?
•lights vs. blix, I tried leaving the print longer in the blix with no sucess too.
I wrote the chemistry seller, asking if he had any other reports about the Blix he sold me.
In the mean time, I tried going beyond 2,5x the concentration of the Blix and I almost got a streak-free print.
The contrast is great!
But the streaks still show a random pattern, I experimented with the agitation in the first 5 seconds of the blix and was able to "control" the pattern of the streaks. Not very cientific, but in a weird way, I found when it happens. Could the fix be fast and the bleach slow?
Well, was the blix a 2 part blix? If it was a single part, then it may be bad and the extra concentration might be fixing that problem.
I'd get all new chemistry and start with that. It sounds like chemistry issues. I don't even use stop bath for RA-4 and have never had any problems like you describe.
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I always use a 2% acetic + bisulfite stop for both printing and film. The sulfite stops help to ensure that you do not contaminate the bleach with color developer. PE, care to comment here?
By denying the facts, any paradox can be sustained--Galileo
Originally Posted by Photo Engineer
I use 1 or 2% acetic acid alone. That is good enough.
A single part bleach fix (blix) has been associated with severe problems here on APUG. It is best to use a 2 part blix for paper.
Take a look:
On page 3 is referred the optional stop bath.
It may help...
I got in touch with the people that make the chemistry I'm using.
I explained my whole method of work and in reply they told me I could dilute the developer way more or use a starter.
It was an endless discussion, I figured I was right, they knew they were right.
I tried what they said just to prove them wrong and everything worked fine.
Apparently the developer was too concentrated and I never felt so stupid in my entire life.
I apologize for the post and everything.