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  #1  
Old 23rd October 2016, 12:19 AM
kaifis kaifis is offline
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Default Problem with green / brown speckles in C-41 shadow areas

I am looking for some advise, just having started C-41 processing: As you can see in the attached images, there are green / brown speckles appearing in the shadow areas when I scan my negatives.

The film is Kodak Porta 400 (120), which is not out of date and has been stored in a fridge from when I bought it. It was developed in a Rollei Colorchem C-41 kit. The chemicals had only been mixed a couple of days before I developed this, and only a couple of films had gone through the baths before this one - so well below the chemicals' stated capacities. There are two things which, in hindsight, I did differently from the instructions, although I am not sure if they could have caused this: I agitated the film (in a Paterson System 4 tank) a fair bit more than stated, and I'd added a quick rinse between developer and blix bath. Beyond that, I believe temperatures were pretty exact at 38 degree C, and timing was at 3min 15sec.

What else? For the three weeks in Ghana (where the pictures were taken) the films were in quite a warm and humid environment, although not excessively so.

Just having started with C-41, I imagine it will most likely have to do with something during the processing... and so any suggestions to stop this from happening again would be hugely welcome - in particulary if you happen to have come across this type of defect before!

Kai

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Last edited by kaifis; 23rd October 2016 at 12:34 AM.
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  #2  
Old 23rd October 2016, 07:39 AM
John King John King is offline
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Default C41

Marks like this can occur when a film is kept in a fridge but is not allowed to regain room temperature before opening the foil wrapper, and is caused by dampness on the emulsion. This dampness does not have to be visible to cause the problem. Were the marks on every frame?

My other impression is a problem with the actual processing. What quantity of developer had you mixed before processing the very 1st film? Part used developers, especially C41 colour, do not always take kindly to being left for a couple of days before using them again. This may have exacerbated any problem relating to that in paragraph one.

Another possibility is, unless your measuring beakers, film spiral and internal parts of the tank are SPOTLESSLY clean there can be a small amount of chemical carry over. This is possible even if they are rinsed out afterwards. I found this out to my cost when I mixed my last batch of RA4 colour printing developer. I had to dump 2 litres of chemical from the NOVA Processor when it became contaminated. I now use only glass measuring beakers which eliminates one source of the problem.
I'm assuming you are using some sort of processor.

What brand of C41 are you using, Not that it makes much difference because they are all generic and can be intermixed.

I have been processing C41 since 1990 or so and have never used colour developer more than once and have never had this problem. I always work on the principal of 'use once then discard'. It may be more expensive but my results are consistent.

To cut down on costs, I have found that buying say a 2.5 litre kit, mixing the developer all at once but storing it in brown glass bottles (preferably in a dark place such as a cupboard) the pre mixed developer will keep without degrading over at least 2-3 months.
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  #3  
Old 23rd October 2016, 08:28 AM
JOReynolds JOReynolds is offline
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Default C41

Yes, the problem relates to processing but not necessarily developer exhaustion. It's best to follow the directions published by the chemistry manufacturer. They have experience and measurement equipment that no enthusiast could hope to own or master. I think that the problem occurs between starting to drain the developer and pouring in the blix. Firstly, why agitate excessively in the developer, although this would not necessarily cause the blotchiness you describe. When you have inverted the tank a few times, knock the tank against the sink to dislodge bubbles. Some types of spiral retain bubbles more than others. Second, why introduce a water step between developer and blix? Undiluted, blix is an effective stop bath but development will continue during a water step and, for as long as it takes to drain the developer, fill with water, drain the water and refill with blix, the blix cannot perform its function if the emulsion is swollen with water. If you want to retain the water bath, do the dev-water-blix steps in the dark, passing the spiral(s) between separate tanks.
If you find that developing for 3m15sec at 38C causes panic, look up the published times for lower temperatures - the procedure will be more leisurely and the results will be just as good.
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  #4  
Old 23rd October 2016, 09:34 AM
kaifis kaifis is offline
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Thank you both for your extensive replies, this is a great help! As far as I scanned them, there are similar marks on all the frames of this film - but I will scan them all and check this.

The brand of C-41 I was using is a 'Rollei Colorchem' 1l kit. I had mixed up the full litre, developed a test film (which came out fine), stored the developer in a brown glass bottle, the blix in a brown plastic bottle and the stabiliser in a white plastic bottle, all with protective gas, and then used them again a few days later to develop this film. The chemicals in the kit are meant to be re-useable for up to 16 films, and for two weeks minimum even if stored in partly-full bottles... at least according to their specs.

I developed the films in a one litre Paterson tank, which is kept in a temperature-controlled circulating mantle bath, and since I'm just starting with my C-41 setup, I had kept a fairly close eye on the temperatures of the solutions throughout the process from pre-soak to wash, and am quietly confident that this side was ok. (I'd spent a fair amount of time testing temperatures before I ran my first film through it...)

So I think that could in this case make two of the possible causes John mentions most likely: chemical carry-over and dampness on the emulsion. The measuring cylinders, storage bottles and funnels used to make up the solutions were all new (and are separate for each bath), since I bought them for C-41 to not mix them up with my B&W equipment. I had cleaned the tank and spirals out fairly well I thought... but maybe not well enough? I did the stabiliser in a separate tank and took the film off the spool for this step, so tank and spools had been washed for five mins already with the film after blix, before I gave them what I thought was a good final rinse once the film was out... but maybe not good enough! Do you extensively soak your spirals after your C-41 use to avoid cross-contamination? (The tank and spools were bought for C-41 as well, so had been new for the test film...)

Which brings me back to dampness, and I think there are two places where this might have happened: I was in Ghana for three weeks, during 'minor rain season' - which is pretty wet, warm and damp, and once the film was exposed, it was stored for a week in its opened wrapper inside a metal box. That would be annoying if this was the problem, since I'm not quite sure how I could avoid that in future, when taking photos on film while away! Store exposed films with silica gel, until back home?? Which does remind me that for the two weeks before exposure, the film in fact wasn't in a fridge but in my hotel room, which had no fridge...

Maybe the other option for dampness to have caused this could be just before developing? The film was stored back in the fridge before I developed it, and I had it out for maybe two hours before loading it into the tank... so I could give it more time?

Regarding Jo's thoughts of this happening between developing and blix, yes that would make sense too. I'd introduced it after reading that quite a few people are doing this (water after dev.), to extend the life of the blix solution - so it would be great to know if others who tried this encountered the same problem! I guess another way to protect the blix would just be a stop bath after developer instead of water? Or should I just not worry about developer carrying into blix regarding it's effectiveness?

Excessive agitation was simply down to reading not-very-clear instructions using this kit for the first time - no other intention behind this!

Will run another test film through the chemicals today or tomorrow, with the spools and tank cleaned as before, and maybe another one with spools soaked for longer, and with a stop instead of water after dev, to try to narrow it down. Thank you again for your help with this!
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  #5  
Old 23rd October 2016, 09:43 AM
JOReynolds JOReynolds is offline
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Stale developer will not cause blotchiness. But I don't understand why, as a C41 beginner, you introduce risky procedures not recommended by the manufacturer. And don't use an acid stop bath! Study the function of reducing agents - developers and EDTA bleaches
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  #6  
Old 23rd October 2016, 10:49 AM
kaifis kaifis is offline
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The reason I went for the rinse after developing is that there are quite a large number of tutorials and forum discussions for C-41 and Colorchem which recommend this, to avoid problems with the life span of the blix - and I think this might partly be due to the fact that the documentations coming with the Rollei kits aren't great, in particular when it comes to blix re-useability and life span. (The instructions for Rollei Digibase, their other C41 kit, in fact don't even mention the need of a wash between fix and stabilising, or of any wash at all... so it would clearly seem to be a bad choice to follow those instructions literally for example!)

Tetenal for their kit do specifically recommend the use of a 3% acetic acid stop bath for their C41 kit (http://www.freestylephoto.biz/static...structions.pdf)... so as with many things, there do seem to be a good many different ways to C-41 happiness! I totally appreciate that citric-acid stop is meant to be avoided though...

One other thing to take from this could be to go for the Tetenal kits, which come with better instructions...
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  #7  
Old 23rd October 2016, 11:08 AM
kaifis kaifis is offline
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Are there C-41 users on this forum who at some stage tried the water rinse after development and encountered similar problems, or who had similar blotchiness but traced it back to a different source (dampness?) - and who might have images they could post with it as a reference?
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  #8  
Old 23rd October 2016, 04:29 PM
John King John King is offline
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Default C41

As I mentioned before, I have been processing C41 for 26 years and I have always followed the same method.

1. No wet tempering bath, the tank is always warmed sitting in the JOBO as soon as the water heater is switched on and only removed imediately before filling with developer.

2. Development 3mins 15 secs development at 38c

3. Bleach immediately afterwards - no water rinse for 7 mins

4. Water rinse for 30secs

5. Fix for 7 mins

6. 6 x water rinse for 30secs each

7. Stabilser bath 1 min - full tank with no agitation

8. Hang to dry for as long as it takes.

The length of time for bleaching and fixing is extended by 1 minute each by personal preference.

In the time I mentioned I have used C41 kits from AGFA (until they went bust) Fuji, Tetenal, and Rollie Digibase all with the same sequence and temperature for processing perhaps close on 750 rolls and cassettes. I have made a mess of perhaps a handfull but that was not down to deviating from my sequence - it was me being clumsy! Yes I use a JOBO CPE2 which makes things easier but the tempering bath mentioned by the original poster will do just as well.
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  #9  
Old 23rd October 2016, 06:03 PM
Mike O'Pray Mike O'Pray is offline
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Just an observation here, kaifis but if you followed the same procedure for the speckled films as you did for the first film which came out fine then this suggests to me that your process wasn't at fault per se although that isn't to say that some kind of contamination didn't creep in as John King mentions

It has been a long time since I did any C41 but I have used several different kits and I cannot recall any speckles appearing. I would have slavishly followed the instructions which in the case of Tetenal, Nova Darkroom's own kit and Michael Maunder's own Speedibrew kits were very good

I followed a long thread on another site on the Rollei Digibase kits and you are right the instructions leave a lot to be desired

I attempted to find out from the various posters' contributions what a comprehensive set of instructions was and here they are based on my conclusions of what I read:

1. Pre-wash 2 x 30 secs( brings the film up to the right temp)
2. Developer 3 mins 15 secs(@37.8C)
3. Stop - 30 secs
4. Bleach - 6 mins 30 secs
5. Wash 4 x 30 secs
6. Fix - 6 mins 30 secs
7. Wash - 4 x 30 secs + 2 x 1 min
8. Stabiliser - 1 min

A fairly lengthy process as you will see but also quite comprehensive

N.B. I have a Digibase kit but have yet to use it so the above set of 8 steps are not based on experience but are what I intend to use when I do C41 with a Digibase kit

Mike
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  #10  
Old 23rd October 2016, 07:48 PM
kaifis kaifis is offline
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Thank you again for everyone's responses, and for sharing your procedures! It is interesting to read about the cutting or shortening of the tempering bath - other than to save time, is there a specific reason for this?

Yes, my test film which was done the same way came out without any speckles, and looked fine to me. (see attachments - these are cropped, hence the grain, and colour balance of scans needs work of course...) These are shot on Fuji Pro 400H though, unlike the 'problem film', which was a Kodak Porta 400.

So I do wonder if your very first response John, dampness or high humidity, might have more to do with the problem than the C-41 process itself. Following your response, I have been reading up on this and there are quite a few statements out there describing colour negative film as much more perceptible to humidity and less-than-ideal storage conditions after exposure than B&W - and conditions in Ghana really were not ideal for keeping film. Although unfortunately, I have not actually found any images online, of photographs which show humidity-damaged negatives!

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