Tetenal c41 troubleshooting + general questions

[morback]

Hello,
I've been searching for some answers to my new endeavour: color developing (soon to be followed by RA-4 printing) and found some useful information but nothing that answered my questions directly. Let's start with the most aggravating issue:


Please have a look at this picture. I modified in Photoshop to try to bring out the issue more clearly. As you can see there are some "foam" looking density variations. These only appear on some frames and not all. I have noticed it in both 35mm and medium format, but as I said, they are not on all frames of the same film (as far as I have noticed).

Here is the processing for this image:

5mn dry pre heat as per JOBO instructions,
Jobo CPP2 on "P" agitation setting,
38C @ 3:15,
Stabiliser: 2 drops in 700ml of water, gentle hand agitation,
Hung to dry at room temperature.


These are very hard to see with the naked eye, but on this particular negative I could see it. There are no residues on either side of the negative.
Tetenal customer service did not get back to me, but a very nice gentleman from Jobo helped me. I am now looking for your opinion and experiences as to what you think causes this.



General questions:

1) the manual indicates different times depending on the number of films, 3:15 from 1 to 4 films, 3:30 from 5 to 8 and so on. If I want to do 8 films at once with fresh chemicals, I use the 3:30 times? For 10 films I would use the 9 to 12 films times (3:45), correct?


2) how do I compensate chemical exhaustion when mixing film speeds? It seem that a 400ASA speed film uses about 30% more chemicals, so do I count one roll of 400ASA as 1,3 roll of 200ASA? Meaning, out of 16 films per liter, I could wash 6x400ASA and 6x200ASA? How about the older 800ASA speed films?

3) there might be a chance for me to do some special developing for some local photographers. I want to provide the best quality possible. Locally I only have access to Tetenal but I travel to Europe from time to time and could get the Rollei kit. Should I bother or is proper developing technique more important than chemical brands for quality?

Looking forward to your input!
m.

 

[Rudeofus]

Just to be sure: can you tell us how much chemistry you used in one dev run, and which film tank you used?

 

[morback]

Sure:

Jobo 2502 (new series with black feels) with 1l of chemicals.


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[Photo Engineer]

The only factor that determines change in development time is the number of film sheets or rolls as described in the manual. AFAIK speed does not need to enter into this. But, you may want to check the Kodak web site. They have a good description of the need for compensation.

Ok, now, as for your problem, I think you may fix it by using a pre wet of 1' at 100F. Also, that looks like severe foaming that can be eradicated by a prewet or by tweaking the amount of developer used.

I hope that you used the rest of the process solutions. They are not mentioned. But just in case, it is often good to use a stop bath right after the development step. This stop is usually 1-2% Acetic Acid.

PE

 

[nbagno]

The stop bath as described by photo engineer cleared up a number of weird stains I had using a Jobo and Tetenal. I use a 1:30 stop bath after development then a 30 second water rinse then the Blix. I don't have a 2502 tank but 1L sounds like an awful lot of chemicals for one process run.

 

[morback]

Hi,

thanks for you answer. I did not explain myself properly. I was not referring to the development times but to the amount of film you can develop. All c41 developers seem to allow for less 400asa film than 200asa for the same volume. So the question was, how do you compensate when dealing with mixed asa workflow?

Yes, the rest of the process solution were used of course I follow the instructions to the letter. When you say amount of developer tweaking, are you thinking more or less? As I said, I use 1L bottles, though by the end (after 16 films) I must have around 800ml of developer in the bottle.

The Jobo fellow's recommendation were to increase agitation and skip (dry) pre-heating. His assumption was that maybe humidity during the pre-heating phase was the culprit.

To me the foam-like structure is quite striking. I wonder if while filling it up (cpp2 with lift) I'm not creating this foam?

nbagno: I usually have 4 rolls in the drum, and yes, it is above the minimum required. According to Jobo the minimum is 640 ml (21 3/4 oz) for the 2553 (I don't have the tank near me, looks like 2502 are the reels, and 2553 the tank number...). Is that extra 360ml too much and foaming up?

 

[Rudeofus]

I was not referring to the development times but to the amount of film you can develop. All c41 developers seem to allow for less 400asa film than 200asa for the same volume. So the question was, how do you compensate when dealing with mixed asa workflow?

C-41 developer is not a process fluid which suddenly falls off a cliff if you develop one extra roll of whatever speed film. Going through (there was a url link here which no longer exists), (there was a url link here which no longer exists) and saw no obvious faults in his negs, even with (there was a url link here which no longer exists) To the contrary, Stefan Lange of (there was a url link here which no longer exists) already sees process deviations after one reuse. YMMV ...

Since you plan on offering this as a commercial service, get some process control strips as soon as you figured out your foam patterns, and check for yourself where your process stands. C-41 was designed and optimized as high volume process with replenishment and permanent process control. If you want to deliver such a service for the occasional roll of film, you will have to do some tweaking yourself unless you want to process each roll single shot.

The Jobo fellow's recommendation were to increase agitation and skip (dry) pre-heating. His assumption was that maybe humidity during the pre-heating phase was the culprit.

To me the foam-like structure is quite striking. I wonder if while filling it up (cpp2 with lift) I'm not creating this foam?

Since the foamy structure looks white on the inverted scan, I assume it is extra density in your negative, yes? If this is the case, then developer spent more time in these spots than on the rest of your negative strips. Did you hesitate when pouring in the liquid, then poured in the rest? Did you spend too much time after pouring out the color developer, before you poured in the next liquid? Did the tank rotate when you poured in the color developer? According to C-41 process data sheets, 15 seconds of extra development are one full stop of push development, which tells me that such things can bite you badly.

 

[Photo Engineer]

Look at the Kodak site on C41 processing in tanks and drums. I think you will find that you can mix and match any speed film, and if you have to increase process times, the type of film has little to do with the changes needed.

Bad stopping by the blix (no stop), can cause darker areas on the film which show up as lighter areas on the final print. I suspect that you are having some problems there by not using a stop (and prewet)

PE

 

[morback]

Since the foamy structure looks white on the inverted scan, I assume it is extra density in your negative, yes? If this is the case, then developer spent more time in these spots than on the rest of your negative strips. Did you hesitate when pouring in the liquid, then poured in the rest? Did you spend too much time after pouring out the color developer, before you poured in the next liquid? Did the tank rotate when you poured in the color developer? According to C-41 process data sheets, 15 seconds of extra development are one full stop of push development, which tells me that such things can bite you badly.

No hesitation while pouring in, tank in constant rotation until the end. You might be onto something. It takes a bit to empty the drum and if foam is in there while I wait for the last drops to come out then it could indeed continue it's development process... I'm not sure how to accelerate the process though. It takes a good 15-20 seconds to empty the drum with the lift... That would make sense...

As for stop bath, I think I read here I can use the same chemicals as for B&W?

Thanks for the info on the ASA. I'll ignore the film speed and process the maximum indicated.

So, things to try:
1) pre wet
2) stop bath (Ilfostop ok?)
3) less chems (closer to minimum required, would also help in emptying the drum faster)

Great input, many thanks to you guys!

 

[Rudeofus]

The good thing about using a stop bath is that you don't have to remove the last drop of color developer before you pour in stop bath, the stop bath kills developer action anyway. This alone should improve process repeatability and homogeneity across the frame.

A while back PE mentioned that Citric Acid does some bad things to color processes, that's why he recommended an Acetic Acid stop bath. Sadly he couldn't tell us any details, but this Kodak publication claims that Citric Acid plus Rapid Fixer removes the orange mask (i.e. hurts dyes), something you want to avoid at all costs in normal color processing.

 

[Terry Christian]

Why only two drops of stabilizer per 700 ml? Stabilizer/final rinse is not the same thing as Kodak Photo-Flo and should be used at the manufacturer's recommended dilution.

 

[morback]

Why only two drops of stabilizer per 700 ml? Stabilizer/final rinse is not the same thing as Kodak Photo-Flo and should be used at the manufacturer's recommended dilution.

When used as recommended I get a lot of milky streaks.

 

[Photo Engineer]

I think that is the reference. I could not find it at all.

Citric Acid can hurt dyes!

PE

 

[Rudeofus]

When used as recommended I get a lot of milky streaks.

I assume you mean milky residues outside the emulsion side, not something within the emulsion. You should be able to wipe this residue away with a damp sponge or piece of cloth. Anything else is most likely not caused by the final rinse.

The (there was a url link here which no longer exists), aka STAB, for C-41 film contains a biocide which prevents growth of fungus and other tiny life forms that may feast on your film. Insufficient concentration of this biocide will not offer you this protection, and this will obviously not become apparent right away, but could irrecoverably damage your negs in the years to come.

 

[morback]

Yes, I understand that. But that was the only solution found (and recommended to me). What would be the minimum effective ratio then?


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[Rudeofus]

Yes, I understand that. But that was the only solution found (and recommended to me). What would be the minimum effective ratio then?

Assuming that kit makers won't put chemicals into a kit that have no effect, I would follow Terry Christian's advice and use final rinse "at the manufacturer's recommended dilution".

PS: did you try a damp sponge or piece of cloth to get rid of this residue?

 

[morback]

Well, I used a microfiber cloth, but I thought I should remedy the disease and not the symptoms. Or is everyone in the same boat? I think Robert Vonk from Fotohuis mentionend somewhere that stab can be diluted up to 50% more than indicated?

 

[Rudeofus]

Well, I used a microfiber cloth, but I thought I should remedy the disease and not the symptoms. Or is everyone in the same boat? I think Robert Vonk from Fotohuis mentionend somewhere that stab can be diluted up to 50% more than indicated?

You can dilute it to homeopathic dilutions and won't see any adverse effect right away. As a matter of fact some kits didn't even come with a STAB solution. Under optimal conditions film would last forever, but how sure are you that your film will always be stored in a cool and dry place? General consensus, tells us, that we need to protect our negatives with a biocide. Unless Mr. Vonk can point me to published data that proves, that an extra 50% dilution fully maintains the archival stability of color negative film, I would rather choose the conservative route and follow the kit instructions.

With that dry microfiber cloth you mentioned I would expect that you smeared the residue all over the film surface, but did not effectively remove it. My recommendation of a damp cloth (dampened with deionized water, of course), should take care of that residue for good, without putting the STAB's protective function in question.

 

[Photo Engineer]

Dampen with Stab or Final Rinse please.

PE

 

[morback]

update:

after getting some slight bubble stuff still, I followed PE instruction to the letter. It came out without bubbles (the first temp/water wash comes out with bubbles, so that might explain my first problem) but I feel there is some uneven development/color.

Sequence:

1mn water wash
3:15mn developer
1:30mn stop (sprint blok 1:9 dilution)
water wash
4mn blix
wash wash wash
1mn stab

Two example from the last film:

I seem to see some discolouration (blue) in the corners... Or is it just my eyes/screen? Only medium format seem to be problematic, 35mm has no issues (unless developed alongside a 120 film)...

Is this optimal result, or have I just exchange one set of issues for another?

m.

 

[Photo Engineer]

It is difficult to see the non-uniformity issues in these scenes as they are so "busy" with objects of different types. They look pretty good to me.

What I do see is that your blix time is very short. Usually a bleach and a fix for C41 can require anywhere from 6 - 8 minutes. You might look into this. Also, when I see good negs from 35 mm and a hint of a problem with 120 or larger, I look at solution quantity and amount of solution used. If you use too little, foaming can take place at the corners, and even if you use enough, high agitation can cause foaming along one edge.

PE

 

[morback]

Yes, it think the "business" hide a lot of "defects" in my self developed rolls. About this one in particular, I cannot really see it, but I can feel some uneasiness. I developed another 120 today, this time with 2 washes before developer and no stop bath. The idea being that the stuff that washes out from 120 might create the bubbles that overdevelop parts of my film while I empty the developer.

Here is another thought. I developed 4 35mm yesterday and only one film came out with something very similar but "blurry" :

And then a new issue:

So my new thought is this. It's still the stab. I'm not running it through the machine anymore, all I do is dunk the reel in the end and that's it. And I think this might still be a problem. I notice foam on the edges on medium format, and in the above example this was on only one film out of four processed together. So I'm guessing that one reel still had some stab residues on it.

I brought all my reels home and will scrub them in hot water to try to clean them as best as possible.

Also, is this too foamy?

It's my developer after pouring it back.

 

[Photo Engineer]

The answer is not in the stabilizer, provided you clean your used reels well.

The third picture shows distinct bromide drag which comes from incorrect agitation. The swirls on the first two are probably from bad agitation as well, or bad pouring of the developer or blix. If you pour the developer or blix in in an uneven fashion, then you run the risk of streaks like this.

PE

 

[sfaber17]

Also, is this too foamy?

I would say it is way to foamy. You shouldn't have any foam. Most people don't dare put their reels in the stabilizer. Those who do, scrub them thoroughly. Jobo warns against it.

 

[morback]

What is bad pouring / agitation in relation to cpp2? It doesn't seem I have much option as to pouring... For agitation I can only control the RPM...


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