More E-6 questions

Daniel Lawton · Nov 9, 2005

Hello everyone. So far I have processed 2 rolls of E-6 (Velvia 100) in Kodak's single use kit and they look pretty good but I had a couple of lingering questions. The first concerns the final washing method. Kodak recommends "3 or 4 short washes over 6 min if flowing water is not used." Would the Ilford wash method for B+W be sufficient for this purpose? Is there any danger of over-washing E-6 film and damaging the dyes? Secondly I hear different things about the use of formaldehyde stabilizers versus the "Final rinse" contained in the kit. Specifically, the formaldehyde stabilizers seem to be designed for processes that include a full wash and the "Final rinse" is for minilab processes that leave lots of residual fixer in the film. Basically I was wondering which is better for archival purposes when used with small tank home processing methods. Would the dyes last longer if I were using a formaldehyde stabilizer instead of the final rinse that comes with the kit? Lastly I also read on one of the APUG forums where someone said you have to use hot air to dry the film or else the dyes won't properly stabilize. Is there any truth to this? Kodak's info simply says "not above 140
deg F." Currently I have only been drying them at room temp. Like anything else with film processing there is alot of hearsay so I was trying to get the "real deal " so to speak. I know there are lots of people hear with a wealth of info.

gbroadbridge · Nov 9, 2005

Assuming you're talking about C41 colour process, you just need to wash, stabilize, and wash again. The result is archival.

Most stabilzer baths contain formaldehyde. Dont stress, but do wear gloves

Graham.

Daniel Lawton · Nov 9, 2005

Perhaps I am using the wrong terminology. By stabilizer I meant the final rinse solution contained in the E-6 kit which is to be used after the final wash and then hung to dry. As I understand it, Kodak has eliminated or significantly decreased the formaldehyde content of the solution. I'm not too worried about the health issues since I take the necessary precautions but rather I was wondering if the this solution is as archival as formaldehyde versions.

Photo Engineer · Nov 9, 2005

gbroadbridge said:
Assuming you're talking about C41 colour process, you just need to wash, stabilize, and wash again. The result is archival.

Most stabilzer baths contain formaldehyde. Dont stress, but do wear gloves

Graham.

Under NO circumstances should you wash after the stabilization step!

This applies to C41 and E6.

The stabilizer and final rinse solutions are different products intended for different chemical and processing conditions. Use the appropriate solution for your processor.

PE

Daniel Lawton · Nov 9, 2005

OK thanks PE. What about washing and drying? I noticed in some of your other posts where you refer to a full wash compared to a shorter one. What methods would constitute a full wash for E-6? Also does temperature matter when drying the film. Maybe I'm being paranoid but I'm just trying to make sure I do it right. Thanks

Dan

Photo Engineer · Nov 10, 2005

Dan, you cannot just wash and dry a color film. Nor can you wash and use photo flo or the like. You must finish color film processes with either a stabilzer or a so called "final rinse". These solutions contain ingredients necessary for dye stabilzation.

As for wash cycles, there are those for home processes (drum, tank, rack, etc) and for minilabs which use different chemistry and reduced wash rates and water flow. The chemicals are different in both cases and use of a given cycle with the wrong chemistry can cause problems.

If you use the RA C41 chemistry, the wash cycles are different than the straight C41 chemistry. I use straight C41 in my Jobo and use extra long washes with a good change rate. I have excellent dye stability. No surprise there to me. My washes meet or exceed the flow rate and times of the EK/Jobo instructions.

PE

edz · Nov 10, 2005

Photo Engineer said:
The stabilizer and final rinse solutions are different products intended for different chemical and processing conditions. Use the appropriate solution for your processor.

Actually not really. Its only that some vendors moved their use of Formalin in E-6 (which is needed) to a pre-conditioning bath instead of the final rinse which gets reduced to a stabilization bath to reduce the demands for washing. If you rinse your films well in water and use a Formalin based final rinse you can use it with ANY and ALL C-41 and E-6 process kits.
What is important in E-6 is the protein fixative (Formalin) and higher temperature drying. If you use a non-Formalin final rinse (for example Kodak's) with a chemistry chain that did not use Formalin in an earlier intermediate (for example Agfa's) you would be missing the cross-linking step needed to hold (embalm) the organic dyes.

Photo Engineer · Nov 10, 2005

edz said:
Actually not really. Its only that some vendors moved their use of Formalin in E-6 (which is needed) to a pre-conditioning bath instead of the final rinse which gets reduced to a stabilization bath to reduce the demands for washing. If you rinse your films well in water and use a Formalin based final rinse you can use it with ANY and ALL C-41 and E-6 process kits.
What is important in E-6 is the protein fixative (Formalin) and higher temperature drying. If you use a non-Formalin final rinse (for example Kodak's) with a chemistry chain that did not use Formalin in an earlier intermediate (for example Agfa's) you would be missing the cross-linking step needed to hold (embalm) the organic dyes.

Ed, the C41 stabilzer is still Formalin CAT 856 8792

RA4 Stabilizer LORR CAT 897 5146 is an Isothiazolin derivative

E6 Final rinse and replenisher CAT 890 9590 is a proprietary thiazolin -3- one, and finally, the E6 pre bleach CAT 164 6058 contains thioglycerol.

The only one still containing formalin that I could find was the C41 stabilizer.

The purpose of the formalin is to react with excess couplers to form the methylene bis coupler and prevent discoloration due to oxidation and light, and also to prevent reactions from taking place between the coupler and the dye which would lead to formation of leuco dye and loss of density.

Washing or using photo flo after the stabilzer would defeat the purpose by washing out the stabilzing chemistry before it had a chance to react with the couplers. Heat is not necessary for this reaction. Drying down will do it nicely.

It is my understanding that the E6 pre-bleach is there to help the bleach oxidize silver to silver halide rather than do anything for the dye stability. It reduces silver retention in highlights.

Older films from EK required formalin, but the more recent films from Kodak don't. You can use the newer stabilzers due to a newer coupler set. You can see notes to that effect on their web site. There are notices about mixing certain types of film in differently stabilzed processes. If you mix film types, it is best to use the formalin stabilzer to be on the safe side with both old and new film stocks.

I don't know about Fuji or Agfa films. At one time they all required formalin.

PE

edz · Nov 10, 2005

Photo Engineer said:
Ed, the C41 stabilzer is still Formalin CAT 856 8792

RA4 Stabilizer LORR CAT 897 5146 is an Isothiazolin derivative

I've only addressed C-41 and E-6. RA-4 is quite different and the final rinse is a stabilizer which really more a superwash.

E6 Final rinse and replenisher CAT 890 9590 is a proprietary thiazolin -3- one, and finally, the E6 pre bleach CAT 164 6058 contains thioglycerol.

The pre-bleach probably still contains formalin. I suspect the thioglycerol is in some buffering to significantly reduce the amount of Formalin needed (to get it under the MSDS radar perhaps) and discharged.

The only one still containing formalin that I could find was the C41 stabilizer.

Some companies do it even trickier. Tetenal, for instance, announced some years ago that their new C-41 final rinse was free of Formalin. It technically but effectively was/is not as they were/are based unpon Hexamethylenetetramine which decomposes to Formalin

Do films need the Formalin? Even though many films today come with a a Glutaraldehyde fixative built-in, a Formalin final rinse is still beneficial.

Photo Engineer · Nov 10, 2005

edz said:
I've only addressed C-41 and E-6. RA-4 is quite different and the final rinse is a stabilizer which really more a superwash.

The pre-bleach probably still contains formalin. I suspect the thioglycerol is in some buffering to significantly reduce the amount of Formalin needed (to get it under the MSDS radar perhaps) and discharged.

Some companies do it even trickier. Tetenal, for instance, announced some years ago that their new C-41 final rinse was free of Formalin. It technically but effectively was/is not as they were/are based unpon Hexamethylenetetramine which decomposes to Formalin

Do films need the Formalin? Even though many films today come with a a Glutaraldehyde fixative built-in, a Formalin final rinse is still beneficial.

Ed, I am quite familiar with all of that work. One of my patents covers the use of the bisulfite addition product of formalin for stabilzation, and the early E1 kits used paraformaldehyde (polyoxymethylene) or erroniously named sometimes trioxymethylene. That is how I keep formalin safely stored in my darkroom as a matter of fact so that I can mix it up from powder as needed.

I do not believe that hexamethylenetetramine (methenamine) decomposes readily into formalin. It is a nitrogen containing compound that can do this, but my handbooks don't even mention the decomposition as being important and the ammonia (amines) generated would not be beneficial photographically. I suggest that they might be using paraformaldehyde in the Tetenal kit, but it isn't important, as the final end product is formalin in either case, I guess.

AFAIK, there is no formalin in E6, and there is no glutaraldehyde fixative in any Kodak film. The solution is in the selection of the new couplers which do not need the formalin treatment. Kodak films used to use formalin hardener but changed in the 60s to a new hardener. All formaldehyde products were then eliminated from the coatings as the aldehydes in general were too reactive and caused a lot of side effects. This effect of formalin took place during keeping and resulted in a reduction in speed, contrast and color coupler activity in B&W and color films respectively. The new hardener solved these keeping problems.

There was a fogging effect also present due to the use of aldehydes. Any aldehyde in film is not good (look up 'silver mirror test' in analytical chemistry). The aldehyde tends to oxidize and the silver reduces. Very bad.

So, AFAIK, the only remaining aldehyde (lets say disclosed for sake of argument) is in C41 stabilizer and is not really needed for some modern films according to data on the Kodak web site.

PE

magic823 · Nov 10, 2005

Damn, I love these techie posts! Makes me want to go back to school and get a chemistry degree.

nworth · Nov 11, 2005

Photo Engineer said:
The only one still containing formalin that I could find was the C41 stabilizer.

PE

This is true for Kodak, but other kits still use formalin stabilizers for E-6.

Photo Engineer · Nov 11, 2005

nworth said:
This is true for Kodak, but other kits still use formalin stabilizers for E-6.

Sorry, I should have been more clear.

First, I was just referring back to my original post with the product #s from Kodak kits. and Second, Tetenal, which was the only other kit really mentioned says that they don't use formalin but really do in the form of the precursor.

Thanks. I hope that this is a bit more clear.

PE

Daniel Lawton · Nov 11, 2005

PE, you mention that Kodak's newer E-6 films don't require Formalin but are not sure about AGFA and Fuji. Does that mean I could possibly be jeapordizing the stability of Fuji films by processing them in the Kodak kit I bought? I use both Fuji and Kodak E-6 films so is it better to use another kit that is compatible with films that may require formalin?

Photo Engineer · Nov 11, 2005

Daniel Lawton said:
PE, you mention that Kodak's newer E-6 films don't require Formalin but are not sure about AGFA and Fuji. Does that mean I could possibly be jeapordizing the stability of Fuji films by processing them in the Kodak kit I bought? I use both Fuji and Kodak E-6 films so is it better to use another kit that is compatible with films that may require formalin?

Well, that depends on whether there is formalin in the conditioner bath, or whether the new 'stabilizer' I mentioned above will work for all films.

I honestly don't know enough, but I do know that Kodak goes to great length to NOT injure or degrade films from other manufacturers. We routinely tested Agfa and Fuji films for all parameters so as to insure compatibility within reasonable limits.

I truly doubt that there will be a problem.

In addition, there is so much cross licensing and andvance notification of changes between the companies, that there is little doubt in my mind that anything would go bad or wrong. The note about older films and newer films being different in this regard (on the EK web site) makes me feel that they would have mentioned Agfa and Fuji if there were a problem.

If you have any doubts, give the film a formalin treatment in the old stabilzer, but I would check with Fuji on that. I doubt if there would be any harm in the treatment or there would be notices elsewhere about it.

Has anyone checked out the Fuji web site? There might be information there.

PE

Daniel Lawton · Nov 11, 2005

Thanks again PE. I figured that since velvia 50 is one of fuji's older E-6 emulsions if there was a Fuji film that required formalin it would be this one. While I couldn't find any specific info on this subject they do say that Velvia 50 is designed for Kodak E-6, Fujifilm process CR-56 and Fuji/Hunt C6R. Being that the Kodak E-6 chemistry doesn't contain formaldehyde, it seems apparent that formalin/formaldehyde shouldn't be required for Fuji films either as you eluded to. Once again your knowledge on the subject has been extremely helpful to me.

Dan

gbroadbridge · Nov 12, 2005

Photo Engineer said:
Under NO circumstances should you wash after the stabilization step!

This applies to C41 and E6.

The stabilizer and final rinse solutions are different products intended for different chemical and processing conditions. Use the appropriate solution for your processor.

PE

PE, you are quite right, and I don't know what I was thinking when I suggested washing after stabilization. I just air dry.

Graham.

Baxter Bradford · Nov 12, 2005

Photo Engineer said:
I honestly don't know enough,
PE

I couldn't possibly disagree more.......

I think you do! A veritable photographic oracle.

And am in awe of your expertise and willingness to help on this forum.
Thank you very much for all of your contribution PE.

Photo Engineer · Nov 12, 2005

Baxter Bradford said:
I couldn't possibly disagree more.......

I think you do! A veritable photographic oracle.

And am in awe of your expertise and willingness to help on this forum.
Thank you very much for all of your contribution PE.

Baxter, thanks.

I really wish I knew more, and that my knowledge was more up-to-date.

I'm always glad to help. When you get 'old' the best thing you can do is pass your knowledge on to others.

I constrain myself to answers, and sometimes get too technical, but I could really go far beyond what I have posted sometimes, for example going into system design (emulsion, film or process) and other things not of general interest.

Anyone interested? Just contact me. I'm here.

PE

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