E-6 Reality Check on Wikipedia

Photo Engineer · Aug 23, 2007

Nick;

These are the correct formulas except:

1. You cannot and must not use Sodium Ferric EDTA in the bleach.
2. The first developer uses HYDROQUINONE MONOSULFONATE K salt. THIS IS NOT HQ.

I stress this strongly. Also

3. Note the presence of thiocyanate in the first developer!!!!!!!

These changes are critical to the functioning of the first developer and bleach. Unfortunately, I don't have the color developer formula.

The conditioner bath is correct. No current E6 process contains formalin AFAIK. The new couplers do not require it.

PE

Nick Zentena · Aug 23, 2007

I can type in the colour developer if some body wants. It just seemed the discussion was centering on the other parts.

Photo Engineer · Aug 23, 2007

I didn't say anything Nick because I cannot remember that formula and have no copies here. IDK if it is right or wrong, but your track record would make me think that the BJP has the right formula. (except for NaFeEDTA being a no-no).

Post the CD too.

PE

Photo Engineer · Aug 23, 2007

I would like to add that many equate HQ with HQ monosulfonate, but they are not the same. HQMS is milder and diffuses differently. HQ begins development rapidly in the top layer before diffusion has even taken place.

So, this upsets the balance of the development of the layers.

The SCN is needed to completely develop the emulsion and clear out the dmin of the positive image by developing all of the coated silver.

I cannot tell you the formulas, but I can tell you if you get it right.

I hope you understand.

PE

Nick Zentena · Aug 23, 2007

colour developer pH 11.6

EDTA NA4 3g
Potassium carbonate anhydrous 40g
sodium sulphite anhydrous 4g
potassium bromide 0.5 g
potassium iodide 1% solution 3 ml
citrazinic acid 1.2g
hydroxylamine hydrochloride 1.5 g
water to 1litre

Nick Zentena · Aug 23, 2007

Oops need to finish it-)
Add before use CD-3 10g
They also give the option of CD-4 7.5 g

Nick Zentena · Aug 23, 2007

They give alternatives for the first developer and bleach. Plus the choice of CD-4 versus CD-3. The alternatives look like the Watkins formulas I think. I wonder if the idea was to create something with easier to get [more common] chemicals.

Photo Engineer · Aug 23, 2007

Do not use CD-4. The image stability and dye hue will suffer as well as image stability.

In addition, and this may be important, but I think that the E6 CD used a high pH phosphate developer. As I said, I don't have the formula, but it seems to me that IIRC, the pH was around 11.x or something. This cannot be if you use carbonate.

Sorry I don't have that one thing in my memory.

I would have to say that you got everything but the color developer if my memory is reasonably accurate.

PE

Discpad · Aug 24, 2007

Thank you PE and Nick: I'll be updating the article this weekend, and posting a note here when I'm done.

Also, thank you PE for explaining the difference in action between hydroquinone and hydroquinone monosulfate.

Discpad · Aug 25, 2007

OK, PE and Nick, I updated most of the Wikipedia E-6 page, except for the fixer formula.

Photo Engineer · Aug 25, 2007

Dan;

The p-aminophenol in the reversal bath seems incorrect.

Also, the use of a ferricyanide bleach with no clearing bath is very bad.

The stabilizer can stand as is, but the modern formula has no formalin in it.

PE

Discpad · Aug 26, 2007

Got it... I'll correct it tonight.

stefan4u · Oct 29, 2007

E6 color developer

Here a really good working color developer reciept, I've done some researches and test, just try it...

Color Developer:
Aqua demin...750ml
Calgon2.0 g
Trisodium phosphate crystals . 36.0 g
Sodium hydroxide 10% solution ..19 ml (as much as needed to get a pH of 11,9)
Sodium sulphite, anhydrous .. 5.5 g
Sodium bromide .0.55 g
Potassium iodide 0.1 per cent solution 36 ml
Sodium thiocyanate1.0 g
Citrazinic acid 0.6 g ( don't use more or contrast and Dmax will suffer)
CD3 10.5 g
Water to 1 litre
pH 11,9-12,1

If using tab water, you have to take a different sequestering agent, such as HEPD and EDTA 4Na. Calgon only (hexametaphospate) will lead to percepiates...

Regards,
Stefan

Photo Engineer · Oct 29, 2007

Kodak did not use the current Calgon for any purpse since they changed the formula in the mid 70s.

PE

stefan4u · Oct 30, 2007

Dear PE !!

Yes, that calgon is a (known) bug, that's why I pointed to HEPD and EDTA 4Na. Another bug is the absence of 3,6-Dithia-1,8-Octandiole, which is not affordeble for me...
Anyway, this CD works really fine and since I found a forgotten bottle of mixed Kodak RA4-RT cd replenisher in the fridge which stood there for about 10 months and was in perfect working condition, I take Aqua demin. for all color developers...

But I do have still questions about the conditioner / pre-blech bath. Till now I've skipped that step, stopped after the CD rinsed for 4 min. and then went to the bleach. The bleach I use is not a E-6 one, its a C-41 bleach (replenisher) which I use undiluted in order to have an increased concentration of FeIII EDTA. Bleaching time is 10 min. Compared to tetenal 3 step chemistry (cave, Blix ...) the result is identical, but compared to commercial developed slides the D.min seems slightly increased.

Apart from using a different / adapted bleach,
if I mix up a conditioner bath with EDTA 8g to improve bleaching,
Sodium sulfite 10-12g to sulfonate residuals of oxidised CD and make them water soulble,
would it be better to use Thioglycerol 0,4 g or Mercaptotriacole as a bleach accelerator ??
I've read about the use of optical brighteners, (xy-stilbene) like "blancophor reu" in small ammounts in order to reduce dye stain. Does this makes sense, thought normal projection lamps do't, (or do only in minor ammounts) emmit UV ray's ??

Regards
Stefan

Photo Engineer · Oct 30, 2007

I could not make any suggestion for a prebath other than what Kodak uses. As for sequestrants in developers, Kodak used Quadrofos at the time I worked on that type of thing.

Kodak now uses Nitrilotriacetate IIRC, instead of EDTA in the C41 bleach. I can't remember if they changed over for E6. This is the new C41 Bleach III.

I would not use whiteners in film processes. They tend to yellow with age and when still active, can cause bluish color shifts.

The use of DTOD (the dithio ether alcohol) in the developer is far superior to thiocyanate.

PE

stefan4u · Oct 30, 2007

Dear PE !!

Thank you very much, seems I have to try harder to get the DTOD for the color developer and use a different bleach. Very calming too, that you don't recommand optical brighteners....

Regards,
Stefan

Photo Engineer · Oct 30, 2007

Well, Kodak sells DTOD at a very high price and only in bulk. There are several smaller sellers including one in Germany and one in the US. Prices range about $200 / 1/2 KG.

PE

stefan4u · Oct 30, 2007

Uuups, this makes clear why it's hard to get...

Propably I will do a minor increases of the Tiocyanate in the Color developer instead, maybe accompanied by a slight decrease of Citracinic acid to maintain Dmax. Then brewing an adequate Conditioner instead the stop bad, followed by a stronger bleach.

The results by now are quite well, anyhow they don't justify such extraordinary expensive stuff. It's only a hobby, consumption of time is OK if not desired but this...

Thank's a lot and regards again,
Stefan

bwfans · Dec 16, 2010

This thread come up all the time when I am searching E-6 formulas. But the current wiki article deleted all the references to the formulas. Does anyone know why and if the formulas in the 2007 wiki article is worth to be posted here, and if those are still the better version of published E-6 formulas?

Thanks.

stefan4u · Dec 18, 2010

High bwfans

I dont know weather and why the formulations are deleted either, but luckily there is a very good compilation of a variety of formulations on google docs. Feel free to praise M. Stanton for this goodie

https://docs.google.com/View?id=dhb94mck_38crprhxcf

In this compilation you will find, next to all color formulations you need, the persulfate/quinone bleach you asked for in the suggested replacement for Kodak e6 kit thread.

Highly recommended, print it out!

Recommandable no less is the following:

http://www.freepatentsonline.com/5948604.pdf

If you calculate it down you will find a very usable E6 formulation from Kodak (!).
This is a bit thinner than the normal (replenishable) E6 formulations, because its intended for single use only. You will remark that the FD contains only 18.4 g/l Potassium hydroquinone monosulfate instead of 22-24g/, the CD only 8.4 g/l CD3 instead of 10-10.5g/l, CZA only .6 g/l instead of 1.5g/l and so on. But in my eyes at least the FD is VERY usable mainly because the right developing agents are involved.

If you decide to take plain HQ in the first developer you have to add Benzotriazole (look at the google.docs compilation) for reducing the hyperactivity/unevenness throughout the emulsion layers and the occurring color shifts. This is considered as the wrong approach, but its an attempt
Regards,
Stefan

bwfans · Dec 22, 2010

Thanks Stefan I really appreciate your detailed help!

I just browsed the first link - it is the best source on E6/C41 chemicals/formulas.

E-6 Reality Check on Wikipedia

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