RA-4 prints coming out green?

1kgcoffee · Jul 18, 2019

Edit to add - thanks for the replies but I figured it out and its very silly. Chemicals and paper are good, but I happened to leave a graded filter for black and white printing in the carrier from my previous session!
Interesting problem here:
I printed off some negative film onto kodak endura with the usual settings. The unexposed borders are perfectly white, with good blacks and highlights yet tinted with a heavy green. Basically a green print. This led me to think perhaps the developer is off - its been sitting for a few months. If it were bad blix the borders would not be a perfect white.

So I use some fresh developer. Nice straw colour to signify freshness. But same results.

My question here is, if it is the blix, then why are the borders perfectly white? I understand that the borders should have colour dyes in them for the same greenish tint.

(I have to portion out my supersize container of blix before eliminating this last element.)

1kgcoffee · Jul 18, 2019

Alright, tried with fresh blix and same problem. I'm stumped...

Kino · Jul 18, 2019

Filter pack or dichroic head?

foc · Jul 18, 2019

Normally a green print means dev is contaminated with bleach-fix but you are getting white borders so it doesn't look like a dev problem.

Could it be a colour correction problem in the enlarger, new batch of paper, faulty colour head / lamp?

jamesaz · Jul 18, 2019

I'm gonna go out on a limb here but did you try taking magenta out of the pack? It is not unknown for paper to shift its response to light with age.

1kgcoffee · Jul 18, 2019

God I can be stupid - there was a magenta grade filter for printing black and white in the filter stage carrier. Havent tested yet but I'm sure that was the problem.

Kino,
To answer your question its an rgb LED bulb but I never had this issue with these settings. Funny thing is the magenta light that came out looks similar enough to usual rgb setting that I didn't notice.

pentaxuser · Jul 18, 2019

I take it that you are not a newcomer to RA4 printing and have had success with RA4 prints previously? If so then what I am about to say may be completely irrelevant but when I first tried RA4 from a properly processed C41 it was a print of the statue of the little boy in Brussels who is urinating and that came out green and yes my borders were fine like yours. To this day I am unsure what I did wrong but I can only conclude it was my filter balance so Kino's question may be on the right lines in terms of getting to a solution. From what you have said it would look as if it has nothing to do with the chemicals which leaves colour filtration as the likely cause

Did you go on to make other prints of other negatives and if so how did they turn out? It may shorten the time taken to reach a solution if you were to show us the negative and what your filter pack/ dichroic head filtration was and other examples of good or green cast prints.

The more you can give us in terms of information the quicker one of us or a collection of us can reach an effective solution.

pentaxuser

Kino · Jul 18, 2019

Problem solved = all good!

koraks · Jul 19, 2019

1kgcoffee said:
its an rgb LED bulb

Out of curiosity and my apologies for going slightly off-topic: can you share some details on the light source and filtering? Is it basically an additive color setup, or do you turn all colors on and then use subtractive filtering with a dichroic head or under-the-lens filters? How is the setup working for you in general?

BMbikerider · Jul 19, 2019

Don't worry it is all a learning curve, for some steeper than others.....at times.

In over 30 years of RA4 printing (on and off) I think I have made about every mistake in the book. Exposure mistakes, colour balance corrected the wrong way, badly developed films, etc etc and the list goes on. There was one problem I never managed to correct and that was occasionally, I would get random colour variations in patches that varied positions from print to print. Then not appear again for several months. New developer or bleach fix made no difference, it still came back.

I normally use a LPL7700 enlarger, but even after borrowing a Kaiser, the problem still manifested itself. Luckily, this seems to have self cured...how I don't know. I have not done anything to alter my methods or equipment and the problem has for the past year or so not appeared. It will remain one of life's little secrets.

1kgcoffee · Jul 19, 2019

koraks,
One caveat. Some of the more experienced members believe that it is not up to part with dichroic or additive heads. They do not recommend it. This may be the case as LED light sources are in their adolescence and do not have the colour purity of true dichroic light. Myself personally, I am very satisfied. Both in terms of cost, heat generation and results. It compares favourably to the minolta 45a head whose prints look very similar.

The bulb is a LIFX housed in a condensor, controlled by cell phone or tablet. Technically it's additive, but rather than controlling RGB, you control hue, saturation and darkness. When I am not doing something retarded like leaving graded filters in it produces very nice sharp prints.

pentaxuser,
I think you are correct in both our cases. I'm not sure how you managed to set the wrong filtration, but I managed to pull the wool over my own eyes and waste a few hours. All in good fun. Just as I was about to make the 4th (correct) print a friend stopped by but I'm sure with fresh chemicals and the usual settings it should produce something very nice.

1kgcoffee · Jul 19, 2019

BMbikerider said:
Don't worry it is all a learning curve, for some steeper than others.....at times.

In over 30 years of RA4 printing (on and off) I think I have made about every mistake in the book. Exposure mistakes, colour balance corrected the wrong way, badly developed films, etc etc and the list goes on. There was one problem I never managed to correct and that was occasionally, I would get random colour variations in patches that varied positions from print to print. Then not appear again for several months. New developer or bleach fix made no difference, it still came back.

I normally use a LPL7700 enlarger, but even after borrowing a Kaiser, the problem still manifested itself. Luckily, this seems to have self cured...how I don't know. I have not done anything to alter my methods or equipment and the problem has for the past year or so not appeared. It will remain one of life's little secrets.

Funny, I had a similar problem. Turned out that the bulb was sitting too close to the condensor, causing different colour balance in different parts of the print. It was subtle and I loved the fact that I was now making real ra-4 prints so didn't care. In my case raising the bulb using a roll of masking tape to shim it up evened out the colour balance. I think I damaged the condensor when I first bought it.

koraks · Jul 19, 2019

1kgcoffee said:
One caveat. Some of the more experienced members believe that it is not up to part with dichroic or additive heads. They do not recommend it. This may be the case as LED light sources are in their adolescence and do not have the colour purity of true dichroic light. Myself personally, I am very satisfied. Both in terms of cost, heat generation and results. It compares favourably to the minolta 45a head whose prints look very similar.

The bulb is a LIFX housed in a condensor, controlled by cell phone or tablet. Technically it's additive, but rather than controlling RGB, you control hue, saturation and darkness. When I am not doing something retarded like leaving graded filters in it produces very nice sharp prints.

Thank you for your response! Yes, I'm very much aware of the caveat. One particular issue is the central wavelength of the leds in question, particularly the red, which in LEDs is generally significantly below the peak sensitivity of RA4 paper. I am interested in your experiences as I've been working on a DIY RGB led head for my Durst 138. So far, the test results are quite promising, but so far I've only done a handful of color prints, but I have calibrated the setup for VC b&w and it performs very well for that purpose. Next step is to calibrate the color mode so that it works intuitively (ie similar to a dichroic color head). I still have to do some rigorous testing and frankly I do expect some differences between the led head and a "proper" color head, but I suspect I will probably be able to live with these differences. Hence my interest in the experiences of people who already use leds for color.
BTW I like your approach using an off the shelf solution; very convenient. It bypasses the hardware and software engineering I'm working on, although my "build from scratch" approach does provide more flexibility - it comes at a price though, but financially and in terms of time. But it's a fun project so far.

BMbikerider · Jul 19, 2019

1kgcoffee said:
Funny, I had a similar problem. Turned out that the bulb was sitting too close to the condensor, causing different colour balance in different parts of the print. It was subtle and I loved the fact that I was now making real ra-4 prints so didn't care. In my case raising the bulb using a roll of masking tape to shim it up evened out the colour balance. I think I damaged the condenser when I first bought it.

There is one thing that would definitely not affect the LPL 7700 and that is the fact it doesn't have a condenser! The light goes straight from the bulb reflector into the polystyrene mixing box through a heat filter. The colour changes resembled light streaks, very similar to very pale sunlight shining through a stained glass window. However where they appeared were totally random. Sometimes in the centre, sometimes on the right and other times on the bottom edge - really odd.

DREW WILEY · Jul 20, 2019

I have true additive RGB halogen colorheads as well as traditional CMY subtractive. But I can't envision anything in LED being in the range of spectral accuracy suitable for high quality color printing at this point in time, though it might be fun to experiment anyway. Designing an effective mixing chamber is an additional issue.

koraks · Jul 21, 2019

Yeah, it's a bit of an experiment. It helps that for me, dead-on accuracy is not a strict requirement as it is for you, so I may just get away with murder. But we'll have to see; it's still in the experimental phase.

DREW WILEY · Jul 21, 2019

Your experiments might come in handy later on, as LED options steadily improve. Just think of it as a prototype. Not every rocket design gets off the ground successfully. A few blow up. But that's how you learn.

koraks · Jul 21, 2019

That's right; it's kind of a Frankenstein device, but it seems to work in a way. I just did a session of tiny prints to get a feel for how it works and to my surprise, it does so reasonably well. In fact, I don't get much better prints from my regular M605 color head, so it seems to be OK for my purposes.
If I were to start from scratch, I'd hunt down some more appropriate leds; particularly the red ones seem to be critical. Many red leds have impure spectra with distinct green and yellow peaks, which is obviously undesirable. I think Cree, Osram and Lumileds have chips that are more usable - but they require reflow soldering which is something I'm a bit hesitant to drag into the picture. I currently use an integrated COB RGB module, which obviously is quite convenient - but also a compromise. Honestly I suspect the technology is ripe already, at least the crucial parts. It's just a puzzle waiting to be integrated.

RA-4 prints coming out green?

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