Help diagnosing C41 development issues

[avose55]

Hi everyone! I'm a new user, newbie home developer, and first time poster. I have just began developing color negative film at home over the past month, and have had less than ideal results across my first four rolls using the ADOX C-TEC 41 Developing Kit (Mixed in 500ml batches) and a Paterson universal developing tank.


My first roll turned out decent with some very slight color shifts and uneven development, but overall passable and better than expected for my first attempt.

For this roll, I followed the directions for 38°C exactly as written in the ADOX dev kit datasheet. I maintained a water temperature of 38°C using a sous vide and measured the temperature of the chemicals to make sure they had reached the desired temp before beginning development. The tank was be agitated for the first 30 seconds continuously inside the water bath, and then inverted once every 15 seconds. The tank went back into the temperature controlled water bath after each agitation.

My second roll came out with heavy magenta casts, even though I followed the same procedure as the first roll and stored the chemicals in accordion containers will all of the air removed.

Below is an example of the difference in the negative base color in a roll developed by a lab and my roll developed at home, as well as a scan showing the magenta cast. What would cause the drastic difference in base color and magenta color cast? I am scanning with a Nikon Coolscan 5000 and can get accurate colors when scanning lab developed negatives.

I originally thought that it was due to poor temperature control and temperature fluctuations during agitation and pouring the solutions in and out of the Paterson tank. Before I developed my next roll of film I ran through the developing process using water in place of active chemicals and logged temperature measurements at different points. I found that from between removing the bottle from the water bath and pouring the solutions into the tank, I was losing ~0.5°C. Then after agitating via inversion once every 15 seconds, and the completion of the 3:15 dev time, I was losing almost 1°C. To remedy this, I increased the temperature of the water bath to 40°C and only started developing once the chemicals had reached 39°C so that dev would start and finish at 38°C ± 0.5°C.

This also did not help so I went on to mixing up a new batch of chemicals. Surprise, surprise, I still have heavy color casts and different colored film base when comparing to the same film stock that had been developed at a local lab.

Any insight would be greatly appreciated!

 

[koraks]

Welcome aboard @avose55 !

The tank was be agitated for the first 30 seconds continuously inside the water bath, and then inverted once every 15 seconds.

In principle, the frequency of agitation is fine, but "inverting once" might be a bit gentle. The essence of agitation is that it's, well, agitated. So it shouldn't be too gentle. If your single inversion is rather brisk, that's fine. If it's more akin to handling a two-day old kitten, it may be too subtle.

The photo of the two negative strips is too small to make out much, sorry. If you could post a larger version, that would help. The only thing I can say is that the top strip looks all wrong; it looks like over-developed ECN2 film. The bottom strip looks more like normally processed C41 film. What kind of film are we looking at here? And how was the top strip labeled 'Lab' actually processed?

The inverted color image (that does look very magenta indeed) shows odd density variations that could have several explanations. They might be simply be fogging to light or the result of uneven agitation and/or fill/drain rate problems (taking too long to fill/drain).

I think the ADOX instructions do not instruct you to use a stop bath, but I would recommend using one in a manual process anyway. You can make a perfectly fine stop bath for this purpose by diluting unscented cleaning vinegar by about 1+10 with tap water (use one shot; discard after use).

For more sensible comments, please post a larger picture of some of the affected negative strips.

 

[loccdor]

The inversion I do is to turn the tank from vertical to its side and back at a medium speed. If you hear that bubbly sound that rushing water makes when it goes very fast and mixes with air, that's too fast. You want to avoid surge marks. For C-41 I like to do 4 inversions every 30 seconds.

I have never divided the one liter kits. I always store them in liter bottles. Is it possible the solutions were not completely homogenous when they were divided?

Maybe a stupid question, but is it the exact same film with the same expiration date that you are comparing between lab and home? And which film is it?

 

[koraks]

If you hear that bubbly sound that rushing water makes when it goes very fast and mixes with air, that's too fast. You want to avoid surge marks.

I'd like to nuance this a bit. The point of agitation is to create a turbulent flow. This can create some sound by definition. That's perfectly OK. The risk of surge marks is not necessarily related to over-agitation; it's the effect of a mixed turbulent & laminar flow patterns that varies across the film surface. Overly gentle agitation carries a bigger risk in this sense than overly brisk agitation. One of the main determinants of surge marks are film type (120 and sheet film are more readily affected also because the image extends to close to the edges where any surge marks are more likely to emerge) and tank & reel/holder geometry (the 'claws' of the MOD54 are infamous).

 

[loccdor]

You could be right. But in my trials of semi-stand development, 30 seconds initial agitation plus one very gentle inversion at the midpoint of a 10 minute development was enough to get rid of all the negative side-effects of a full-stand development, so I struggle to reconcile that.

 

[avose55]

In principle, the frequency of agitation is fine, but "inverting once" might be a bit gentle. The essence of agitation is that it's, well, agitated. So it shouldn't be too gentle. If your single inversion is rather brisk, that's fine. If it's more akin to handling a two-day old kitten, it may be too subtle.

I invert the tank fairly quickly with a half turn which takes about a second to complete. Maybe it is too gentle? But I do hear the solution moving through the film reels.

Here are better photos of the two batches of negatives I’m comparing. They’re both Portra 400 which were exposed and developed normaly. Neither rolls were out of expiration and they sat for maybe 2-4 weeks between being exposed and being processed.

Lab developed negatives:

Home developed negatives:

Side by side:

 

[koraks]

semi-stand development

I'd be hesitant to draw parallels between agitation schemes with 10+ minutes between cycles and a scheme that approximates continuous agitation. It's correct that you can usually dramatically improve the problems in a fully stand development scheme by introducing one or two agitation cycles somewhere in-between the process. But this issue is different from the question how vigorous agitation should be in something like a C41 process.

Lab developed negatives:

The color of the base and overall color of the negatives is far more red than how Portra is supposed to look. Either the white balance of the digital photo of the negatives is extremely far off course, or there's a serious problem with how that film was processed. I suspect it's the latter. Is this a small 'boutique' lab or a large commercial outfit? Do you know how they process their film?

Home developed negatives:

These look more normal, but there is an odd shift towards blue. I do see some signs of light leak problems, potentially in the camera:

I'm not sure if this explains the overall blue/yellow shift entirely.
The odd blob in the second snippet above seems to be of the same general shape and in the same spot as the one you showed earlier:

My first guess is that this is a camera-related light leak. What kind of camera did you use for this film?

In your C41 process, do you use a stop bath? I would recommend this when developing manually with tanks.
I would also recommend running one strip of your film through the blix again (room temperature, 10 minutes would be OK) to see if this makes a difference. Although the 'blob' above seems more of a camera defect (since it's located in the same spot on two different frames), there's a chance that we're looking at retained silver, which will throw the color balance out of whack.

 

[avose55]

The color of the base and overall color of the negatives is far more red than how Portra is supposed to look. Either the white balance of the digital photo of the negatives is extremely far off course, or there's a serious problem with how that film was processed. I suspect it's the latter. Is this a small 'boutique' lab or a large commercial outfit? Do you know how they process their film?

I snapped these with my phone this morning before heading out to work, so it’s safe to assume the white balance is causing the lab developed Portra to look far more red than normal. All of my Portra negatives are a slightly deeper color than Kodak Gold 200 for example, which is a lighter orange. It’s a small local lab which I believe uses a noritsu with the standard c41 process.

My first guess is that this is a camera-related light leak. What kind of camera did you use for this film?

I’m shooting with an Olympus OM-2n which I’ve never had any signs of light leaks from since replacing the seals about a year ago.

In your C41 process, do you use a stop bath?

I haven’t looked into it yet. I just started out so figured it was best to stick to the kit instructions but after reading through a bunch of threads here, I’m going to add one.

 

[koraks]

All of my Portra negatives are a slightly deeper color than Kodak Gold 200 for example, which is a lighter orange.

Are you referring to lab-developed Portra and Gold? Can you show them side by side, please?
Again, the lab-processed strips look way, way too red. The only time I've ever seen something like that is when I mistakenly over-developed ECN2 film by a massive degree. It's far outside the normal bandwidth as far as I can tell now.

The light leaks along the sprocket holes can also be the result of the felt light trap failing somewhere in the process; in itself this is not a major concern. The yellow spots on the film along the roll are more problematic. I'm not sure yet what causes them.

See if the stop bath will make a difference for future rolls, and whether the re-blixing helps for this particular film. The rest of your processing sounds OK. Also, a temperature deviation of e.g. 1 degree will generally not produce very dramatic problems. No, the negatives will not be perfectly on spec, but most people won't even notice, especially not when film is scanned and then post-processed digitally.

 

[avose55]

Are you referring to lab-developed Portra and Gold? Can you show them side by side, please?

Yes the Porta 400 has a deeper base color than Gold 200 developed by the same lab. Both scan perfectly so I have a hard time believing that they were processed incorrectly, it must be something with the iPhone photo processing. I’ll scan a couple examples as positives and post later on.

 

[koraks]

Perhaps this illustrates my concern. Both strips are the exact same film. Left was overdeveloped due to a gross mixing error in the chemistry. Right is normally processed.
Healthy Portra looks closer to the sample on the right.

To be sure: the film on the left scans just fine.

 

[avose55]

Maybe this will help more. Here is a photo with white balance set to 5000K.

Top to bottom:
1) Kodak Portra 400 - Self Dev
2) Kodak Portra 400 - Lab Dev
3) Kodak Gold 200 - Self Dev
4) Kodak Gold 200 - Lab Dev

Everything that I have developed has a color cast, with the roll of Portra being the worst. The gold I developed came out pretty good, but still leans magenta

Here are the inverted negatives with no edits:

Portra 400 - self dev

Portra 400 - Lab dev

Gold 200 - Self dev

Gold 200 - lab dev

 

[koraks]

OK, it looks a little more normal now; thanks.

The Gold doesn't look too weird, but I agree that the dmin is very different. Inverted and crudely color balanced, the self- and lab-developed samples aren't worlds apart though:

This suggests that whatever is happening on the base is likely some relatively minor fogging on either roll - and I'm not convinced that your own roll is the one that's problematic.

I agree that the Portra roll is basically FUBAR. There's almost no color information in it. IDK what went wrong there; my first thought would be a major problem with e.g. chemical contamination, fogging to light etc. Was this the same chemistry (as in, the exact same batch) that you used for the Gold? Did you first develop the Gold in that batch of chemistry and then the Portra, or the other way around? If it was first the Gold and then the Portra, my guess would be that there's a contamination problem in your process.

Can you describe exactly how you handle your chemistry, please? From initial mixing all the way to present.

 

[foc]

I know it's always hard to assess a negative on screen but I wonder could the difference in the orange mask colour between home and lab, be caused by under fixing?

I know you are using a kit with blix (bleach/fix combines), where as commercial C41 has separate bleach and fix.

If you extended the time of the blix, to say 6 minutes, how would the results look like? C41 bleach and fix go to completion so you can't over-bleach or fix your film.

Just an idea?

 

[koraks]

I wonder could the difference in the orange mask colour between home and lab, be caused by under fixing?

Referring to the Gold 200 rolls, the interesting bit is that his home-processed roll has a lower d-min than the lab-processed film:

Thinking about this a little more: the difference seems to be that the lab-processed film as a more magenta base. This makes perfect sense if you keep in mind that the lab apparently uses a minilab machine, which means that the wash cycle will be pretty minimal. @avose55 mentions doing a 6 minute wash at 30-40C, which is pretty thorough (assuming it involves at least one or two changes of water). This will wash out more of the magenta sensitizing dyes; I think we recognize how stubborn these dyes can be (try to get perfectly clean wash water from a Kodak C41 film - there's always a little magenta!) Perhaps this is the simple explanation behind the difference in base color between the Gold films.

With the Portra film something odd is going on. That one has significant yellow dye stain all over the film apparently, and the color balance is out of whack even if you correct for this yellow/blue bias.

 

[avose55]

I agree that the Portra roll is basically FUBAR. There's almost no color information in it. IDK what went wrong there; my first thought would be a major problem with e.g. chemical contamination, fogging to light etc. Was this the same chemistry (as in, the exact same batch) that you used for the Gold? Did you first develop the Gold in that batch of chemistry and then the Portra, or the other way around? If it was first the Gold and then the Portra, my guess would be that there's a contamination problem in your process.

Yeah it's pretty bad. This batch of chemicals was used to develop the Gold first, then a roll of Ultramax (which came out somewhere in between the Gold and Portra quality wise), and then finally the roll of Portra.

After these 3 I discarded the full set of chems and mixed up the second half of the concentrates, figuring I'd start from scratch. I tried developing a roll of Portra 160 which came out equally as bad but with red shadows and cyan highlights upon scanning. So I think this is pointing me to a bad batch of concentrate?

Can you describe exactly how you handle your chemistry, please? From initial mixing all the way to present.

I mix all of the concentrates the same way:

1) measure specified amount of distilled water using a glass graduated cylinder and pour into a 1000ml pitcher
2) measure specified amount of CD part 1 using a glass graduated cylinder and pour into a 1000ml pitcher
3) measure specified amount of CD part 2 using a glass graduated cylinder and pour into a 1000ml pitcher
4) measure specified amount of CD part 3 using a glass graduated cylinder and pour into a 1000ml pitcher
5) Pour solution from 1000ml pitcher to 500ml amber bottle

6) Rinse both 1000ml pitcher and graduated cylinder with hot water and final rinse with distilled water

7) measure specified amount of distilled water using a glass graduated cylinder and pour into a 1000ml pitcher
8) measure specified amount of Blix part 1 using a glass graduated cylinder and pour into a 1000ml pitcher
9) measure specified amount of CD part 2 using a glass graduated cylinder and pour into a 1000ml pitcher
10) Pour solution from 1000ml pitcher to 500ml amber bottle

11) Rinse both 1000ml pitcher and graduated cylinder with hot water and final rinse with distilled water

12) measure specified amount of distilled water using a glass graduated cylinder and pour into a 1000ml pitcher
13) measure specified amount of Stabilizer using a glass graduated cylinder and pour into a 1000ml pitcher
14) Pour solution from 1000ml pitcher to 500ml amber bottle


Handling chemicals during development:

1) Open developer and pour into dev tank
2) Dev step is finished place funnel into developer bottle and pour developer back
3) Rinse film & twizzle stick with water for 30 seconds and dump (this will be replaced with a stop bath)
4) Open blix and pour into dev tank
5) Cap developer and rinse paterson tank lid and funnel
6) Blix step is finished place funnel into blix bottle and pour blix back
7) Rinse film for 6 min and dump (twizzle stick, paterson tank lid, and funnel are rinsed)
8) Cap blix
9) Open stabilizer and pour into dev tank
10) Stabilizer step is finished place funnel into stab bottle and pour stab back

All bottles have color coded caps that have not been interchanged. I use argon gas to displace oxygen in bottles before storing.

 

[avose55]

assuming it involves at least one or two changes of water

If I don't keep the faucet running it's probably about 6-8 changes of water

 

[gbroadbridge]

8) measure specified amount of Blix part 1 using a glass graduated cylinder and pour into a 1000ml pitcher
9) measure specified amount of CD part 2 using a glass graduated cylinder and pour into a 1000ml pitcher

Presume you mean BX Part 2 in item 9.

 

[avose55]

Presume you mean BX Part 2 in item 9.

Yes copy and paste error

 

[koraks]

a bad batch of concentrate?

99.96% of these problems are some form of user error; the trick is to figure out what went wrong here exactly.
Given that your rolls seem to have become progressively worse, I lean stronger towards a contamination problem. Specifically blix contamination of the developer. I'm not sure how/where that happens in your process; it looks good on paper. It depends a bit on how effective the rinse of the funnel and the paterson lid is (the latter is kind of notorious due to its shape), and also whether the storage bottles were perfectly clean to begin with.

In principle argon gas would be OK, but gases diffuse, so don't rely on a 'blanket' of gas, as it will not really work. However, if you have properly capped bottles, this shouldn't be an issue.
Personally I'm not fond of amber bottles because it's impossible to see the color of the contents. I prefer to use clear glass and store the chemistry in a cupboard. Of course, contents can be poured into a clear beaker for inspection in case of doubt.

Did your developer smell of ammonia, even if only a tiny bit?

 

[avose55]

Did your developer smell of ammonia, even if only a tiny bit?

Not that I can tell, no.

It sounds like my best bet would be to order new concentrates and start from scratch.

 

[koraks]

Okay, just checking. In some cases of (usually quite severe) contamination it's possible to detect an ammonia scent that results from the fixer part of the blix breaking down in the developer. However, even a tiny bit of contamination that would go unnoticed can/will have a dramatic effect on the working properties of the developer. Contamination of the developer with bleach and/or blix/fix is one of the most notorious problems in color chemistry.

It sounds like my best bet would be to order new concentrates and start from scratch.

Yes, I would say so; at the very least you know you're starting with a situation that should in principle work.

 

[Samu]

Using a 30 second water rinse as a stop bath could be the problem. It is most likely not stopping the development uniformly in all layers. Use acetic acid stop bath instead.