C-41 and E-6 Tetenal kits - Some troubleshooting

[propeller808]

Maybe a lab guru can jump in with some knowledge, I've run into problems developing with Tetenal kits. But since I develop large volume I have reasons to stick with them, so maybe I can iron out the issues.

Fresh C-41 develops nice enough, although there seems to be inconsistencies how film "overdevelopes" slightly on the sides, nothing major. Using the white balance pipette tool in Lightroom I see about 1-3% of difference in the Red channel between sides and center of the negative. I suppose I can live with it.

But when I develop long expired or even moderately expired film, the results are awful. There's extreme brown base fog that I have never been able to fix with re-blixing. Scanning that is disastrous, extreme color shifts, the sides of film completely burnt.

E-6 also develops dark and rather grainy. I often notice slight color shifts.


I develop using the Filmomat. What makes this machine special is it blows air in the tank instead of rotating agitation, then the cap of the tank shakes to throw the air bubbles back off the film. I doubt it's the machine though. I suspect something to do with the chemicals. All issues happen with fresh batches. I've tried the Tetenal leaflet troubleshooting with no answers.

How has your Tetenal experience been?

 

[Asha]

when I develop long expired or even moderately expired film, the results are awful

E-6 also develops dark and rather grainy. I often notice slight color shifts.

. I doubt it's the machine though. I suspect something to do with the chemicals

It's a long time since I used colour film and souped in tetenal kits ( both C-41 and E6) , however I don't recall having serious problems like what you are having.

Expired film , particularly colour, is probably not going to go in your favour so my response to that is avoid using anything but fresh if you demand perfect results.

Dark, grainy and colour shifts with the E6 sound too much like temperature issues to me but I'm far from an expert in colour films / developing, much prefering monochrome.

Sadly I am limited to the advice i can offer ....I'm sure others will help more

 

[propeller808]

The machine has a pretty clever temperature control system, it holds your chosen temperature in a flowing water bath which surrounds the tank and chemistry containers.
But expired film shouldn't look like that. With film getting more expensive, people are saving cents buying the already expensive expired stuff.

Black and white is much more organic, more variables. Much more convenient to develop by hand, no problems there

 

[trypdal]

How has your Tetenal experience been?

I only have experience with the C41 1L kit which I use sporadically with both 135mm and 120 film. Unlike you I do not do it professionally - I use an AP tank and do not invert, but constantly agitate using the twirl stick. I only use fresh film. I have had zero problems so far: my results are satisfactory, development is uniform, colours invert correctly after scanning the positives and the cleanliness of the resulting negative is superior to what I was getting when I used a C41 lab.

 

[dmb]

I note on the Filmomat website that they have moved from air agitaion to rotation for the latest model (and have an upgrade path) which allows more films per run. As I spend effort in keeping air away from my developers (C41 and B&W) I wonder if that is a factor. I know some industrial developing systems used gas agitation but inert nitrogen rather than air..

 

[Mostly Vintage Cameras]

Respectfully your best bet might just be to call Tetenal, they are very helpful as a rule. 0116 289 3644

 

[Asha]

But expired film shouldn't look like that. With film getting more expensive, people are saving cents buying the already expensive expired stuff.

Very much depends on the source and how it has been stored!
I fully understand the reasons for using expired film and am not opposed to using some myself.
If however perfect results are expected then fresh film and chemicals is, I think , a sensible place to start, don’t you??

It’s quite possible that your issues lie elsewhere and if that be with the chemicals ( you show your own suspicions in the opening post), then the advice to contact the manufacturer is imo the best advice offered so far.

 

[propeller808]

I appreciate the replies! I have a reply ticket opened with Tetenal

@dmb - I suspect that's because of the workload, they use chemical replenishing systems. The Tetenal consumer kits which I use are marked for small quantities anyway.

Does anyone have experience with effects of chemical crystallization, limescale or cross-contamination?
I'm thinking this because Filmomat's pump was exchanged for a slightly more powerful one. It was the same make, but it felt more agile, maybe some of the chemicals end up in the wrong place because of this or because of combination of these things. I clean the machine regularly, yet you never know. But these matters would affect a fresh negative surely?

 

[excalibur2]

I'm surprised PentaxPete hasn't posted as he seems to use old films and does his own development for his shots....IIRC

 

[Karl.t1965]

Just a bit of info, the Bellini C41 kit, you can now buy extra developer separately as they say all the other chemicals will last. Still only a 1 litre kit but nothing stopping you buying 2 kits and 2 extra developers for a 2 litre 24+ rolls kit