Tetenal C41 vs Kodak

[pentaxuser]

Thanks Athiril. My thoughts on the ratios are that to be on the safe side I might use 3 parts water to 1 part chems as per the Tetenal blix. In a Jobo 35mm tank and to make figures easy this would be 4Omls bleach or fix and 120mls water.

Can anyone comment on how many times bleach and fix can be re-used and equally importantly is 40mls of bleach or fix sufficient per film. In theory it should be, as even if you mix the two full containers so it is 3L +1L +1L then when you use 140ml for a film the portions of bleach and fix are just as they would be at 40mls per Jobo tank.

Finally what times for bleach and fix processing? My understanding is that neither can be overdone so safest might be the Kodak time which is what?

Thanks

pentaxuser

 

[alanrockwood]

Someone asked about using Trebla chemicals. I have a pdf file from Stephen (Stephen Horton I believe) from CPAC imaging with product descriptions, dilutions, times, and temperatures for using their Trebla chemicals for one-shot processing in a phototherm processor. The file includes information for both E-6 and C-41.

I imagine the instructions would likely work in other rotary processors as well.

I will attempt to attach the file here.

 

[Athiril]

Bisulfate is not used as a fixer. Thiosulfate is the fixing agent of choice in all fixers that I know of. Bisulfate may be an ingredient in some fixers.

In a blix, a fixer can actually drive the bleaching reaction towards removing the silver image and so can assist if the blix is formulated correctly, but most blixes are not done correctly for film.

PE

Tetenal Superfix Odourless is Sodium Metabisulfate though (and doesn't work at all on C41 films as a fixer when i tried it).

Thanks Athiril. My thoughts on the ratios are that to be on the safe side I might use 3 parts water to 1 part chems as per the Tetenal blix. In a Jobo 35mm tank and to make figures easy this would be 4Omls bleach or fix and 120mls water.

Can anyone comment on how many times bleach and fix can be re-used and equally importantly is 40mls of bleach or fix sufficient per film. In theory it should be, as even if you mix the two full containers so it is 3L +1L +1L then when you use 140ml for a film the portions of bleach and fix are just as they would be at 40mls per Jobo tank.

Finally what times for bleach and fix processing? My understanding is that neither can be overdone so safest might be the Kodak time which is what?

Thanks

pentaxuser

Bleach and Fix can be re-used more on their own then they can mixed as a blix with the tetenal kit in my experience.

You can over-fix, I read a thread somewhere that someone left some in some old fixer overnight, so we're talking in the vicinity of hours though, so as long as you dont forget that you left it in the solution, no you cant over do it.

as for 1+3 ratio... it's actually 1+1+3, thus 60 mL of bleach and fix in a 300 mL solution, so I put 60 mL of active chemical to a solution for the bleach and fix bathes as the 'sure fire to work safely' amount. (ie tetenal blix solution is 60ml fix + 60ml bleach + 180ml water and i just separate that into their own bathes)

 

[Photo Engineer]

Athiril, Sodium Metabisulfate is not a fixing agent, I assure you. Sorry.

It is known also as: 1,4-dihydrido-2,2,3,3-tetraoxido-1,4-dioxy-2,3-disulfy-[4]catena, 13455-20-4, 14970-71-9, 7631-94-9, bis(hydroxidodioxidosulfur)(S--S), CHEBI:29208, Disodium dithionate, DITHIONATE, Dithionic acid, Dithionic acid, disodium salt, H2S2O6, hypodisulfuric acid, NSC50070, Sodium dithionate, Sodium hyposulfate, Sodium metabisulfate, [(HO)(O)2SS(O)2(OH)]

In water it normally decomposes into Sodium Sulfate and Sulfur Dioxide. It might be induced into decomposing into Sodium Hypo, and if so then that is the fixing agent.

I doubt if that is the main ingredient and it is not intended as a fix under normal conditions. It is a rather rare chemical. I don't doubt that it could be present.

PE

 

[srs5694]

Thiosulfate is the fixing agent of choice in all fixers that I know of.

Formula #126 in Anchell's Darkroom Cookbook, 2nd Edition is Defender 9-F Rapid Thiocyanate Fixer. This uses potassium thiocyanate as the fixing agent. The description says it works in very low temperatures, or in a matter of seconds at room temperature. This is a B&W fixer, though; I have no idea what it would do to C-41 film. I've never used it. I mention it mainly to see what you have to say about it, since I'm mildly curious about it. (I have no intention of using it, since Anchell says the thiocyanate is a skin irritant, and I prefer to keep my darkroom chemicals as innocuous as possible. I'm happy with the speed of the ammonium thiosulfate fixers I use.)

 

[Photo Engineer]

Thiocyanate is a good fixing agent. It is used in only one commercial fixer on the market AFAIK. That said, it is a minor ingredient in the presence of Hypo! Use of a potassium salt in a fixer is not a good idea as shown in data in Mees and James. Potassium salts fix much more slowly.

Thiocyanate must be used with care. It can have bad effects on emulsion coatings under certain conditions.

You may wish to look at our C-41 blix patent. It uses thiocyanate. I am not unaware of it!

PE

 

[rootberry]

This seems very confusing to me. So is all this advocating the use of kodak chems over tetenal?

 

[Photo Engineer]

Use what works for you! However, keep in mind that Kodak and Fuji work together to share information and exchange patent rights on proprietary chemistry, but others do not AFAIK. Therefore, Kodak and Fuji are guaranteed to have processes as compatible as possible but you can see in another thread that there are even problems cropping up between these two giants from time to time when the processes get out of sync.

PE

 

[pentaxuser]

Use what works for you! However, keep in mind that Kodak and Fuji work together to share information and exchange patent rights on proprietary chemistry, but others do not AFAIK. Therefore, Kodak and Fuji are guaranteed to have processes as compatible as possible but you can see in another thread that there are even problems cropping up between these two giants from time to time when the processes get out of sync.

PE

PE OK would you now like to comment on the ratios suggested by myself and Anthiril and the likely safe usage of bleach and fix in terms of the number of times they can be used and the likely processing times for bleach and fix.

I can't speak for the rest of APUG but I for one respect your experience and knowledge and will not be holding you personally responsible for any issues with my processing of films in C41.

Unfortunately in the U.K and I suspect in other countries except the U.S. Kodak C41 chemicals are only available in almost mini-lab quantities so we are forced to decide between high cost and wastage if we use Kodak chemicals or much lower cost Tetenal chemicals but want to accept your findings that separate bleach and fix is the way to go.

Thanks

pentaxuser

 

[Tom Kershaw]

Pentaxuser,

Take a look at the Fuji-Hunt C-41 kit:

http://www.firstcall-photographic.c...s/0/fuji/fuji-c-41-film-x-press-kit-5-litres/

Tom.

 

[Photo Engineer]

And I have given so many possible Bleach and Fix formulas for RA and C-41 here that I'll leave it to you to do a search.

Sorry, but I get tired typing the same things over and over. My apologies.

PE

 

[naugastyle]

Athiril, I just developed my first rolls in Tetenal chemistry and decided to split the bleach and fix as you did, as it seemed like it couldn't hurt. I was wondering what your normal times for the bleach and fix stages are? I used the time in the manual--4 minutes for each--and the negatives turned out brown. I re-did each step (making it 8 minutes total for each step) and they look much better but I feel like my lab-processed negs are still somewhat brighter orange than this. I'll compare for sure when the rolls are dry. I wouldn't really want to add more time as this already puts it into b/w developing time range and there's a lot of appeal in the quickness of C-41 ! It does make me wonder if 1+4 is too high a dilution, although I understand the reasoning behind it.

 

[hrst]

Fujihunt 5l C-41 kit comes with 2,5 liter bleach, to be diluted 1+1. Due to shipping costs, it would surely be more concentrated if it was possible to make. So, 1+4 dilution sounds quite weak. Blix may work a little different way.

 

[naugastyle]

Tried a couple more rolls tonight. Added concentrate to make each part 1+3, bleached for 8 minutes and fixed for 8 minutes. Negatives were still brown. I'm now beginning to wonder if the Tetenal bleach/fix simply can't work for more than 4 minutes at a time. I redid it for 4 more each bleach/fix and the negatives look fine, I suppose...will have to see after drying if they're still not as clear orange as lab negs. Is there any chemical reason why bleach 8 min / rinse / fix 8 min / rinse would not work but bleach 4 min / rinse / fix 4 min / rinse / bleach 4 min / rinse / fix 4 min / rinse would work?

Of course now I'm eager to try blix as per instructions...these times are going too long to still have not-perfectly-bright negs.

 

[hrst]

It is always best to follow the instructions if you are not 100% sure what you are doing. Blix may be a bit different than just bleach and fix combined. I've got good results with Tetenal C-41 blix. If you want separate bleach and fix, don't buy Tetenal.

 

[Photo Engineer]

It is possible to compound a two part blix that will simply not work if split into a bleach and a fix. In fact, I have done this years ago as a lab experiment. I "proved" that Ferric EDTA would not work unless combined with Hypo. Of course I was wrong. I had designed a bad experiment.

So, splitting may not be a good idea depending on the formulation.

PE

 

[naugastyle]

Yes, I'd considered that too...that perhaps the two bottles cannot be considered as simply one bottle of bleach and one bottle of fix that you mix together. There's probably more to it than that. Oh well, it does seem that reasonable numbers of people get good results out of blix, so perhaps I'll just go back to using it the correct way until this kit is finished, then switch to Kodak if I think I'll be developing enough color to justify it.

 

[darkroom_rookie]

Unfortunately in the U.K and I suspect in other countries except the U.S. Kodak C41 chemicals are only available in almost mini-lab quantities so we are forced to decide between high cost and wastage if we use Kodak chemicals or much lower cost Tetenal chemicals but want to accept your findings that separate bleach and fix is the way to go.

Well, in my country (Croatia), you can easily get a full set of Tetenal mini-lab chems with a double quantity of developer (i.e. six bottles), properly separate bleach and fix in large plastic bottles plus developer starter and two-part stabilizer. All of it sets you back some U$150, and that will process at least 300 36-exposure 35mm films. Is that expensive?

 

[madgardener]

Speaking as someone who is not a chemist, and someone who has tried the Tetenal C-41 kit from Freestyle, I was not overly impressed with the results compared to when I send the film out for developing. I know nothing about the chemistry involved, but I did follow the directions provided with the kit.

My results were less than what I was expecting, though it could be that since it was my very first time developing C-41, I did something somewhere wrong. Basically what happened was the first 6 rolls were grainy but acceptable, but after that things went downhill very fast, to the point that I ended up with a magenta cast on my negatives and had to spend many hours on the computer cleaning them up.

I bought the Digibase C-41 kit with separate bleach and fixer, but sadly the developer part C was bad when I opened the kit. I am waiting to hear back from Freestyle. In the meantime, I am wondering if Kodak sells a kit for home C-41 developing, or am I going to be taking a lot more black and white pictures in the future?

 

[Roger Cole]

Kodak doesn't sell a "kit" anymore. I think you can get the components separately but only in pretty large sizes. Freestyle does sell the powdered C41 made by Unicolor. I have used Unicolor C41 many years ago, though it was liquid. If it's the same stuff just in powder form, it should be fine. Mine turned out fine.

They also sell their house Arista brand. I don't know who makes it, but it is liquid.

 

[hpulley]

madgardener:

I get at least 25 good rolls out of my 1L kits of JOBO/Tetenal 3-bath Press Kit. The grain is excellent to me and I'm not just saying that from scanning, that's from enlarging to RA-4 paper in my basement. The results I get are better than from the photo places near here (been around for decades, used to be very good but now mostly into digital). They don't process much film now so I think the results are worse than they used to be (used to be very good) but today I get better results at home, even with a blix kit.

What times for developer and blix did you use? What temperature did you use? How do you control the temperature? Did you pre-soak/warm as recommended? What agitation regimen did you follow?

 

[madgardener]

It was the Unicolor (Tetenal) kit from freestyle. I am using a Patterson super system 4 tank, and was using Fuji 800 speed film, 24 exposure.

The water temperature was between 101-103, The agitation was the same throughout the process. Constant agitation for the first 15 seconds, and 15 seconds for every minute thereafter.

For the wash, instead of using my Patterson wash hose, I manually rinsed (fill, shake, dump) for 5 minutes, stabilizer for 30-45 seconds, and then hang up to dry.

The first 6 rolls came out ok, but were grainy, and the last 2 (the kit said it was good for 8 rolls) had a magenta cast on the negatives. I realize 800 speed film is going to be a little grain, but this reminded me of the old Disc film, it was that bad.

 

[Tony-S]

Photographer's Formulary carries Kodak's Flexcolor in 1L kits.

 

[Roger Cole]

Unicolor and Tetenal are not the same, unless one has bought the other in recent years.

 

[Roger Cole]

Photographer's Formulary carries Kodak's Flexcolor in 1L kits.

For $29 per liter for just the developer?? Yeah, right, pull the other leg, it's got bells on.