Cyan Color Cast

I am on the cusp of giving up color printing because of the shortage of materials (film, choice of paper, and expensive chemicals) Now another reason may have cropped up and one that I am at a loss to work out what is going wrong.

My set up is in a room approximately 5m x 2.5m narrowing at one end to 1.5m. The wall are painted off white. My 'wet bench' is on one side with a DUKA safelight directly behind me facing the wall so the light is always reflected. The light is at the '10' setting on the adjustable internal baffle. The problem is an almost impossible situation where I cannot get rid of a cyan cast. The RA4 Developer is one made by Fuji, the paper is Fuji. (I prefer Kodak for both of these but they are unobtainable in UK.) The film stock is a mixture of 35mm and 120 Kodak and Fuji. All the processing is done in a NOVA 12x16 deep-tank which is strictly replenished by the recommended quantity of developer (Fuji's figures).

Suspecting the safelight was at fault, although I have used one for at least 28 years with no problems. I carried out a strip test where I exposed a piece of printing paper where I exposed strips of the paper for up to 50 seconds in 10 second steps. It was developed (45s) stop bath (15s) followed by bleach fix (45s) and only on the last strip was there any visible change of colour. Even that was not so much cyan, but just a very faint darkening from the white paper which was of course the 50second step.

I have timed my process from taking the paper out of the box, exposing it under the enlarger, then to putting it into the processor and with a total time of 35s. My average exposure under the enlarger is around 15s using 35mm or 120 film. In the processor that is to all intents and purposes without any light exposure because the borders are pure white.

To try to correct the cyan cast I altered the filtration by adding Yellow and Magenta and even by as little as 5-10units (Kodak values and I never use the Cyan filtration) it just flips to the opposite colour cast. There does not seem to be a happy medium. I have even changed the paper from the one I have been using, to a new box of Fuji with a completely different batch number and that does not make any noticeable difference.

When printing B&W I use the same enlarger and the magenta and yellow filters to change the grades and there is never problem.

BMbikerider said:

just a very faint darkening from the white paper which was of course the 50second step.

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On the color balance of an actual image, this will make for a severe cyan cast. The safelight fog acts as a pre-flash and it can have a significant influence on the printed image even if it doesn't yet visible fog the unexposed margins.

Try developing some prints without the Duka safelight being on. If the cast goes away, you've found your problem.

In my experience, it's very, very hard to work with a safelight with color paper. Color paper from many years ago used to be much slower, so safelights were a realistic option. Now, the only viable way to use a safelight is either to have it at a level that barely makes anything visible, making its usefulness virtually nonexistent, or to use a slightly brighter safelight but only for one or two seconds to quickly locate something. Personally I don't bother with any safelight because it's more trouble than it's worth and there's no safelight level that is actually helpful and won't create color casts or even visibly fogged highlights.

Fwiw I vaguely recall a fairly recent post, perhaps in the last year (?), where someone was also getting a cyan cast. (It might have been visible on the white borders; I don't recall.) The poster finally discovered, or perhaps realized, that there was a fairly new piece of equipment in the darkroom which had a red pilot light. (It was not actual darkroom equipment, but perhaps part of HVAC equipment, or whatever.) Said pilot light was not always on, only coming on intermittently to indicate that a certain function was in operation. So... the red pilot light was not noticed in a normal inspection cuz it happened to not be on at the time. Also, when the guy was printing the pilot light was behind him, so he wouldn't notice it coming on periodically. Nuf said?

Good call, @Mr Bill. It was a ceiling smoke detector as I recall.

Another thing to check is how much your enlarger leaks light. Put a lenscap on your enlarging lens and then plug up all the light leaks you can find.

No smoke detectors in the dark room nor are there any other lights apart from the safelight. Yes there are some minor light bleeds from the enlarger but insufficient to cause any colour casts which would have been apparent when I did the strip test. I used the timer that controls the normal exposure but with the lens cap in place and even then there was only a tiny difference in the strip which received 10 secs exposure to the last one that had 50.

I am starting to think it is the Fiji RA4 developer and if that is causing the cast there is no way I will be able to dial it out.

Are you using correct starter for the developer?

BMbikerider said:

I am starting to think it is the Fiji RA4 developer and if that is causing the cast there is no way I will be able to dial it out.

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I'm using Fuji developer as well. No cyan cast. I don't think it's a very likely cause, really. I've worked with pretty "out there" RA4 developers that were way off spec. Cyan casts are rare, not to say non-existent, with this cause.

Safelight fog, however, is a very obvious and plausible cause. Or perhaps your Duka is sacred enough to rise above any suspicion?

brbo said:

Are you using correct starter for the developer?

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Yes.

koraks said:

I'm using Fuji developer as well. No cyan cast. I don't think it's a very likely cause, really. I've worked with pretty "out there" RA4 developers that were way off spec. Cyan casts are rare, not to say non-existent, with this cause.

Safelight fog, however, is a very obvious and plausible cause. Or perhaps your Duka is sacred enough to rise above any suspicion?

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It is plain common sense that if there is no cyan cast when a piece of unexposed paper is tested in steps from 10 seconds up to 50 seconds in a completely blacked out room and it is only on the 50 second step that a very - very faint change in the paper is detected. That change of tone was not even real cyan - almost an undetectable, barely visible grey.
That only leaves me to think it may be the developer may be the problem. Not the developer per se, but contaminated with either stop bath or bleach fix. I will change the developer today although it is no where near at it's end of life and see what I get.

Are you printing with a new negative? If so, how about printing from an older one which you have already produced a good print from. Try to match it.

BMbikerider said:

It is plain common sense that if there is no cyan cast when a piece of unexposed paper is tested in steps from 10 seconds up to 50 seconds in a completely blacked out room

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Alright, but then I misunderstood when you posted this initially:

BMbikerider said:

I carried out a strip test where I exposed a piece of printing paper where I exposed strips of the paper for up to 50 seconds in 10 second steps.

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With 'exposed' here (in the first instance) I assumed you meant 'exposed to darkroom safelight conditions'. My apologies, I should have asked for clarification of the puzzling quoted sentence.

BMbikerider said:

That only leaves me to think it may be the developer may be the problem.

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Not necessarily. It can be aged paper, it can be dichroic fog due to the stop bath or blix, or it still can be lighting fog but you simply haven't spotted the light source yet. Concerning the latter: I can see fairly well even under very low light levels, but e.g. my girlfriend is near-blind under conditions where I can easily navigate a 'dark' space. It's very well possible you have a light source that you simply haven't spotted. I can't of course tell from here what your darkroom looks like and what the likely culprits may be.

The fact that you saw a difference in the exposure durations suggests that the problem might somehow be related to the handling duration before the paper is being processed. The fact that apparently the 10-second 'exposure' (to what?) strip doesn't show a problem (unless I misunderstood your experiment) suggests the chemistry is certainly not the cause of the problem, otherwise you'd have the same problem all the time, regardless of prior paper handling.

Have you tried taking some paper out of the bag and immediately developing it?
And then having a piece of paper just sit out in the darkroom for 120 seconds, in complete darkness, without exposing it to anything at all, and then developing it?
What differences do you see in the two test strips?

It seems it was none of the above, at least not the safelight or any other lighting problems

I drained he Nova and washed it out several times then re- filled the jacket with fresh water. I mixed new developer, stop bath and bleach fix then left it to heat up. The 1st print showed my colour balance I had been using was quite a way of what was needed. Actually getting into the red end of the spectrum. Probably I was changing it trying to correct the problem- but failing. After corrections to the filtration, the colour cast has now gone.

Success!
I always forget that the Nova processors are like a replenishment line.

The other lesson I feel that needs to be taken here is that in the case of an experienced user such as BMbikerider who has had complete success with a DUKA safelight without casts, then suggestions that it is the DUKA that's the problem should at the very least be much further down the list of faults. There is a tendency to seize on the DUKA as the first cause

For some reason DUKA safelights seem not be used by anyone here except BMbikerider and myself, both of whom have had success with the DUKA but whenever we mention the DUKA we get an almost Pavlovian reaction from members that this safelight is the automatic root of any of our RA4 printing problems


pentaxuser

BMbikerider said:

It seems it was none of the above, at least not the safelight or any other lighting problems

I drained he Nova and washed it out several times then re- filled the jacket with fresh water. I mixed new developer, stop bath and bleach fix then left it to heat up. The 1st print showed my colour balance I had been using was quite a way of what was needed. Actually getting into the red end of the spectrum. Probably I was changing it trying to correct the problem- but failing. After corrections to the filtration, the colour cast has now gone.

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After all this, will you miss the cast?

pentaxuser said:

There is a tendency to seize on the DUKA as the first cause

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From my point of view because I've done quite extensive testing with safelights for RA4 and the unsuccessful attempts produced something that fit the problem description quite well. It was a very plausible cause indeed.
Anyone who has printed extensively on RA4 will confirm that safelights are tricky business in this practice.

koraks said:

Anyone who has printed extensively on RA4 will confirm that safelights are tricky business in this practice.

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I have experimented with a very dark green safelight, which is so dark as to almost be unusable but didn't seem to cause fogging issues. Suspect however that working in complete darkness is the better option.

Tom Kershaw said:

I have experimented with a very dark green safelight, which is so dark as to almost be unusable but didn't seem to cause fogging issues. Suspect however that working in complete darkness is the better option.

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I had a very dark green filter on a Durst tri-color safelight and after 15 mins I still couldn't see my hand 6 inches from my face so was useless but the operative word here, Tom is "suspect"

It is suspect as opposed to know. Darkroom printing of even b&w is getting to be a rarity amongst newcomers to film so the prospect of trying RA4 under total darkness is largely a non starter in my opinion so any safelight that gives newcomers any chance to see safely is to be welcomed

At the right level of light my experience is that the DUKA provides enough illumination to see and to do so safely

pentaxuser

pentaxuser said:

the prospect of trying RA4 under total darkness is largely a non starter in my opinion

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That's like saying that the prospect of being in the outdoors would scare newcomers to hiking away.
Newcomers who would struggle with color casts and fogging would eventually give up; if they'd just work in the dark and find out in 10 minutes that this isn't as difficult or scary as they might have expected, they could have good prints on the first go and be motivated to continue.

pentaxuser said:

At the right level of light my experience is that the DUKA provides enough illumination to see and to do so safely

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Then again in various threads we have encountered the phenomenon that you didn't see color problems that were rather obvious to me. For all I know, what you consider as a safe level of illumination isn't necessarily all that safe.

Sirius Glass said:

After all this, will you miss the cast?

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Not one little bit.

From all the replies to this post it is obvious to me that some responses were made without FULLY reading what I had done and then thinking about what the possible problem is/was and I had already covered light leaks/Duka use and in my mind eliminated them.
As I said, I have been printing RA4 for close on 30 years and always using a Duka as well and this was a completely new one to me.
I suspected the chemistry although it has always been rigidly replenished as per the manufacturers recommendation for both Kodak and Fuji. (they have different rates) Then I read that one possible cause was contamination with stop bath and as the stop bath slot is next to the dev slot...................

I will change my working practices and between every print/test strip I will be wiping down the top of the divider between them especially, the flat topped ledge.

BMbikerider said:

some responses were made without FULLY reading what I had done

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I did read what you wrote in full, but as I indicated before, it was worded in a way that made it hard to follow for me. English is not my first language and as soon as someone repeats words like 'exposure' in the same sentence without specifying what kind of exposure it's about, I might get confused. That's what happened, or otherwise I would have already seen that you had tested the safelight specifically.

Moreover, you also noted a difference in the degree of cyan fog in the strip you exposed to safelight conditions the longest. The logical conclusion is that your safelight in fact *does* do something undesirable. That you choose to ignore this issue, is up to you to decide. I'd be worried about it, and here's why:

If your paper darkens, this means that the color balance has already shifted quite significantly. Now, in general, you can filter your way mostly out of such a color cast and obtain a near-neutral balance. This *seems* to work fine as long as you always expose the paper to the safelight for exactly the same amount of time. After all, longer exposure will create a larger color shift, and that will create a moving target situation. So for one thing, a safelight fogging situation as in your case easily creates a situation where you find yourself chasing your own tail and not being able to figure out what's going wrong.

Secondly, the fact that you can nearly eliminate a color balance problem, doesn't mean that your prints are as good as they can be. If you compare a safelight-fogged (but 'properly' balanced print) with one that was not fogged, you may find that the hues are purer, some colors gain saturation (especially strong primaries) and the prints overall look more 'natural' for lack of a better word.

Now, you can choose to ignore everything I say, and that's perfectly fine by me, but rest assured I don't pull all of this out of my ass. As said before, I spent quite some time testing this particular issue and the above phenomena were very clear observations on my part.

If your paper whites fog even the slightest at a 50 second exposure to your safelights, you have a distinct problem. Either you live with it and create suboptimal prints, or you deal with it. Choice is yours! Good luck and have fun!

pentaxuser said:

It is suspect as opposed to know. Darkroom printing of even b&w is getting to be a rarity amongst newcomers to film so the prospect of trying RA4 under total darkness is largely a non starter in my opinion so any safelight that gives newcomers any chance to see safely is to be welcomed

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I'm a newcomer to darkroom printing and I don't use a safelight (for colour or bw).

(It's probably easier if you don't know what you are missing?)

Unfortunately I was not blessed with the eye sight levels of working in the dark as well a cat nor do I have IR vision to make life a lot easier in the dark room. Yes working with no light contamination would be perfect but life is not perfect - far from it.
As the 'slight' almost imperceptible changes after 50 seconds exposure is not visibly there after 40 seconds and I have the paper in the developer usually less than 30 seconds after removing it out of the packet what exposure there is matters not one jot!
I said I suspected that chemical contamination was the problem and after changing them I think that has proved me right.
I think that the bias against any sort of safelight, especially the Duka, is down to having the light levels adjusted too high in the 1st place, as I discovered nearly 30 years ago. Mine is set at less than 1/5th of the maximum intensity which is still pretty subdued considering the reflected light has to travel to reach the paper. I think I could manage to go a fraction lower, but as the safelight does not give me a problem why should I?

BMbikerider said:

As the 'slight' almost imperceptible changes after 50 seconds exposure is not visibly there after 40 seconds

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The thing is, it is visible as a change in color balance, and that's going to create problems. I explained above.

BMbikerider said:

I said I suspected that chemical contamination was the problem and after changing them I think that has proved me right.

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I don't doubt you were right about that! But I also don't doubt that you have another problem hiding underneath it.

BMbikerider said:

I think that the bias against any sort of safelight, especially the Duka, is down to having the light levels adjusted too high in the 1st place, as I discovered nearly 30 years ago.

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Of course, light levels do matter. But as said before, I've done extensive testing, and there's just not a lot of margin of having a safelight at all, and not creating color balancing problems. The margin is in fact so small that I don't even bother with it for regular use. I will continue my testing, though!

And I don't have a cat's vision - pitch dark is pitch dark for me just as for anybody else. But in a room you're familiar with, it's still very easy to navigate despite a total lack of light. And I do have little beacons of small glow-in-the-dark material that help me orient. That's more than enough to work comfortably by.

brbo said:

I'm a newcomer to darkroom printing and I don't use a safelight (for colour or bw).

(It's probably easier if you don't know what you are missing?)

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Fine but I'd respectfully suggest that you may be the exception that proves the rule

pentaxuser