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Grizzly 6th September 2013 09:33 PM

Help with Tetanal C41 Kit

I am new to home colour processing and wanted a bit of information in regards to developing time. Do I need to adjust developing time for different ISO films? I have just completed my first 2 rolls of 400 ISO film and followed the instructions supplied with the kit. do I need to reduce or increase the developing/Bleaching stages for 200/100 ISO film?

I am using a Patterson tank with room for 2 rolls, can I mix different ISO films? For example; Develop 1- 200 ISO with 1- 400 ISO Film?

Any help greatly appreciated!



Mike O'Pray 6th September 2013 11:49 PM

Hi Chris and welcome to FADU. I have used the Tetenal C41 kit in the past and from what can remember the instructions were quite good.

There may have been no mention of different times for different ISOs in the instructions because there aren't different times :D

All C41 films need 3 mins 15 sec development time. However if I recall correctly Tetenal suggest you extend the times as you develop more films but my memory on this is getting hazy.

However the standard time for all films is certainly 3 mins 15 secs.

Get the temperature correct, follow the times given in the instructions and you'll get good negs.

It sounds as if you don't have a Jobo heated processor as you have mentioned using Paterson tanks. If you are relying on a water bath then I'd be tempted to ensure that its temperature is about 1 degree C above the correct developer temp to allow for its cooling over 3 mins 15 secs and for the time when you invert the tank out of the water.

If you are using a water bath and it isn't thermostatically heated to remain constant and you want to be absolutely sure I'd fill it with water at say 1 degree more then fill the tank with water at the correct development temp and do a dry( or is that wet :D) run and test the temp of the water in the tank at the end of 3 mins 15 secs to make sure it is still the right temp. If not then adjust the water bath temp and try again until you get very close to the right temp for the full 3 mins 15 secs. A drop of maybe 0.2/0.3 degrees C won't critical but if it's more then I'd adjust the water bath temp.

Bleach and fix or is it blix in Tetenal's case is much less critical and the water bath even if it losing heat should be fine.

Let us know how you get on


marty 7th September 2013 07:57 AM

Hello & welcome, Chris. Follow the excellent Mike's tutorial and you won't possibly have any problem. If you have hard water there add some wetting agent in the advised quantity to the stabilizing bath to avoid nasty drying marks. An acid stop bath between development and blix will extend the life of the blix (If I recall correct it is mentioned somewhere in the leaflet). Good luck.

Cheers, M.

Grizzly 7th September 2013 09:25 AM

Thanks guys...I am using hot water from the tap and taking a thermometer reading so the advice about a test run for temp is very wise. I have got 2 rolls to do this weekend so will post my results as soon as I have scanned the negs.

Thanks again!

Grizzly 7th September 2013 11:08 AM

My first colour processing attempt, I got a bit mixed up and instead of rinsing the tank with water after the Blix solution I added the stabiliser. After realising my mistake I then rinsed the tank with warm water THEN added the stabiliser again.
Now after checking the chemicals for my next process I have found the stabiliser is a red colour. i assume it has been tainted by the Blix solution. Is it possible to use the stabiliser again or should I get rid of it and buy some more?
What would be the results if I used this stabliser? Has anybody else made this mistake?

I have also read on a forum thread on Flickr that the stabliser stage is not crucial and it can be skipped and use photoflo instead.
Any ideas?


DavidH 7th September 2013 11:41 AM

Stabiliser is not essential. I had an e-mail exchange some time back with the chap who used to produce the Seedibrews kits(embarrasingly, his name escapes me). Those kits did not have stabilizer included. His tests confirmed that, although the negatives will fade quicker without the use of stabilizer, they will still be good for several years.
Naturally, if you have stabilizer you should use it. The negatives I processed without it are still fine after four or more years.
If you intend to continue C41 processing, my opinion is that the Digibase kit is significantly better than any other I have tried. It's a four bath kit, so not quite as straight forward as the Tetenal, but the keeping properties of both working solutions and concentrates are excellent, and their stabilizer-cum-wetting agent gives superbly clean negatives.

DavidH 7th September 2013 11:51 AM

I have just found an e-mail sent to me by Michael Maunder - yes, I finally remembered his name! This is the relevant part-

Forget stabiliser. In days of yore very necessary, but dyes are now so much more stable and so on. As long as you fix/blix properly, then wash fully, the negs will probably outlive you, particularly as even those 40+ year old negatives can be scanned to restore colour.
The proper stabiliser is formaldehyde and no Elfnsafety Commissar is going to allow that and if you try to buy, you'll get your collar felt as a terrorist, or worse - a chemist who knows what he's doing.

Mike O'Pray 7th September 2013 12:14 PM

Far be it from me to contradict Michael Maunder as I have had good advice from him in the past and used his powder C41 kits which are great if you do only a few films at a time but my understanding is that while modern C41 films are much better, stabiliser still helps protects the emulsion from being attacked by "beasties" that can eat it

Unfortunately I don't think that Photo-flo or other B&W wetting agents can do this.

I cannot say whether your stabiliser has been rendered less effective by blix but to be on the safe side I'd be inclined to dump it and mix fresh stabiliser. At least stabiliser doesn't "go off" as developer does and if unadulterated can be used several times.

A lot might depend on how long you want to be able to produce good prints from the negs and whether this will be done in a wholly analogue way in a darkroom.


Grizzly 7th September 2013 02:44 PM

Well I'm not too bothered about keeping the negs for printing as these are cheap rolls of film (some are Fuji Superia expired films from 2003 whcih I paid about 20p for on a car boot sale!) and some are Agfa poundland film. I have just quickly fired some rolls off specifically for trying out home processing, then scanned in. Unless there is something on there a bit special I have no plans to print any negatives.

As I understand it, stabiliser plays no part in the actual colour development process, it merely preserves the negatives for long life. Is this correct?

So I think I will try processing with the tainted stabiliser and see what happens, then the next time try without the stabiliser and compare results.

The frustrating thing is that I can't find anywhere in the UK that only sells stabiliser.

Thanks for the info all and I will keep you posted on my results.


Mike O'Pray 7th September 2013 05:19 PM

Yes you are right, stabiliser plays no part in the colour process and with cheap film which isn't meant to produce "keeper negs" then I'd keep stabiliser for the future when you might want to get better film and make negs worth preserving.

I think the Digibase kits are sold in either kits or as separate units so it should be possible to buy stabiliser separately. AgPhotographic, one of our sponsors, used to stock the Digibase kits but don't seem to now.

All you can do is a search. Try Firstcall.


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