Color Developer Quest

[Photo Engineer]

Peroxide and other oxidants can be used to increase contrast of color images during color development or afterwards in an amplifier both (See a patent by Travis). It works with many processes, but is complicated by the yellow silver filter layer and by catalytic poisons. Therefore, it works poorly in some films with a yellow silver layer or with DIR or DIAR couplers or with very high iodide films.

I only fully recommend this with the RA4 process.

PE

 

[newcan1]

Ok well I did test 3 today. This is the developer formula I used:

Distilled Water 21 to 38°C (70 to 100°F): 850mL
Sodium Hexametaphosphate: 2.0g
Sodium Sulfite (Anhydrous): 2.0g
Potassium Bromide (Anhydrous): 1.4g
Sodium Carbonate (Anhydrous): 25.6g
Sodium Bicarbonate: 2.7g
Benzotriazole: 5mg
CD-3: 5.2g
Distilled Water to make
1L

I used the published sulfuric acid stop bath, and a ferricyanide bleach.

The image attached below is one of the un-manipulated image scans from this test film. The colors are very close to the original subject. Other images on the film showed colors more vivid than the original, but this is Eterna Vivid film, so that is to be expected. The real question is how well this developer formula will work with other ECN-2 emulsions.

I will try it tomorrow with some old, cold stored EXR 200T film and see what happens.

I should mention that in these tests, I did a pre-soak as the ECN-2 process assumes a pre-soak in removing the remjet backing. In my world, Kodak remjet needs to be removed at the end of the process, but Fuji remjet seems to fall away in the developer. With Fuji films, I may actually presoak in the ECN-2 borax solution instead of water, to see if the remjet will fall away before the developer stage.

One final comment: I have shot certain subjects on other film that appeared to be sharper than the results I got with this film/developer combination. Looking at my developer formula, is there anything that you see that would diminish sharpness? PE has commented that KBr is high, but in fact, the Kodak formula calls for NaBr, and the difference is attributable solely to molecular weight. Does benzotriazole affect sharpness? Maybe I should reduce it further or eliminate it?

 

[kb3lms]

Very nice. I may have to get some benzotriazole.

 

[Athiril]

I haven't had any problems with an acetic acid stop, but I use it one shot, I can make a comparison on the weekend to see if there is a difference. To expand on the reasons I assumed sulphuric acid was used.. it's about 1/10th the cost isn't it of glacial acetic acid, in the quantities used by the motion picture process, that can add up to a lot of savings in overhead, and as far as I'm concerned I'd probably prefer to handle sulphuric acid in a motion picture processing lab for various reasons.

Hi all - thanks for the comments.

I tried again, this time with 5.2g/L CD-3, 28g/L (if I remember correctly) Sodium carbonate (ie a little higher than the published formula), and benzotriazole at 20mg/L. That stuff is really powerful, and in my next test I will reduce it further to maybe 5mg/L. Everything else was per the published formula (except 2g/L Calgon instead of anti-cal 4).

I still have a bit of a cast. Of the images below, "eterna-test2-1.jpg" is a straight, unmanipulated scan showing a slightly greenish cast. The 2-1aa file is color corrected as closely as I can get to the actual subject. For this, on Corel Photo Paint, I added 12 units of blue; nothing else. The third image, 2-1bb, has some contrast enhancement to punch it up a bit.

So the bottom line is...... test 2 needed a little bump in blue to get a correct output.

Any suggestions for how to improve the development of the blue layer? I know I have a lot of variables going on. I am not sure that the benzotriazole is really having any effect on color balance. I will reduce it next time, and eliminate it after that, to see what happens. Increasing the CD-3 seemed to be a good idea, and is perhaps consistent with Athiril's comment above. The cast is less than when I started, although I am using a much fresher stock, and that could account for that.

I could probably acquire some AF-2000, but not the Anti-Cal 4, the minimums are too high.

I have to say, this Eterna Vivid stuff seems pretty awesome - very fine grain for a 500T, and as I paid $90 for 1,000 ft, a lot cheaper than Portra! Now if only I can develop it properly....!

That's funny, here you simply cannot get AF-2000, but can get Anti-Calcium No 4, as Kodak Australia do not import AF-2000.. so I just use the ECN-2 Kit for developer, Part A and B.

You should try a test with no benzotriazole.

 

[newcan1]

Athiril, interesting that you use a part A and part B kit. With C41 I mix a part A and part B concentrate, and then add the CD4 when the concentrates are mixed.

I would like to mix concentrates for my ECN-2 formula. Perhaps PE or another supremely knowledgeable being could advise me which chemicals could be mixed as a part A, and which Part B.

 

[Photo Engineer]

You know that pH is critical!

PE

 

[Athiril]

Athiril, interesting that you use a part A and part B kit. With C41 I mix a part A and part B concentrate, and then add the CD4 when the concentrates are mixed.

I would like to mix concentrates for my ECN-2 formula. Perhaps PE or another supremely knowledgeable being could advise me which chemicals could be mixed as a part A, and which Part B.

What do you mean? With the Kodak Flexicolor C-41 chemicals, the developing agent CD-4 is in Part C, sounds like you do not have a complete kit. And I think Part C is acidic iirc

ECN-2 developer is in 2 parts, CD-3 is contained in part B, there's no HAS which is part B in the Flexicolor kit, part A contains the alkali.

 

[newcan1]

For C-41, I use dry chemicals and mix a part a and a part b stock solution. When I mix them together, and with water, I then mix the cd4 into a small amount of water and add it.

I would like to do the same for my ECN-2 - mix stock solutions and add the CD-3 when I prepare working solutions. I'm just not sure which chemicals would go with which into stock solutions.

I may try without benzotriazole - as I mentioned (but no one commented on), the images are less sharp than others taken on different films. I don't know if the antifoggant is responsible for that or not.

 

[kb3lms]

Here is a two-part formula for ECN-2 that I stumbled upon a few weeks ago that I added to my files. I cannot vouch for how well it does or doesn't work because I haven't tried it. But maybe this is what you are looking for?

These formulae by George Ashton were originally published in Darkroom Techniques in 1983:

Colour developer Part A
Water at 70-80 °F 800 mL
Calgon 2 g
Sodium sulphite (anhydrous) 8 g
Sodium bromide (anh) 4.8 g
Sodium carbonate (anh) 100 g
Sodium bicarbonate 10 g
Water to 1000 mL

Part B
Water at 70-80 °F 80 mL
Potassium metabisulphite 2 g
CD-3 10 g
Water to 100 mL

Mix one volume of A with three volumes of water, then add 10 mL of B per litre of the A+water mix. For example, one litre of developer would be made with 240 mL part A, 720 mL water and 40 mL part B. Use one-shot.

 

[newcan1]

Interesting, KB3MLS - it looks like everything but the CD3 is in part A - which makes sense - I think with C41 only the HAS is in part B, which is not being used here. I think I will take that approach and use my formula to calculate the concentrates.

Is KB3MLS a call sign? Are you a radio ham? (I am).

 

[kb3lms]

Yes and yes. There are a lot of hams in these forums. Analog photography and analog radio seem to go together, especially the vacuum tube boat anchor crowd. I am not in that fraternity, yet.

 

[newcan1]

I guess so. I am KJ4KET. I confess I am rather fond of vacuum tubes, but I won't clog up this thread with that!

 

[newcan1]

PE, here is a question for you, if you would be so kind. I am using Ferricyanide bleach for my ECN-2 and C-41. In another recent thread, you indicated that to prevent staining, the bleach phase should be preceded by and succeeded by a sulfite clearing bath. Would you recommend that here, and if so, what strength solution would I need? I assume sodium sulfite and wonder how many grams per liter. I know the official ECN'2 formula does not require this, but it would not cost much and the official formula only lists the ferricyanide bleach as an alternative.

 

[Photo Engineer]

Any color developing agent carried into a Ferricyanide bleach bath will oxidize and if the solution is not very acidic the developing agent will couple with the film and form stain. In some cases it is so severe and non-uniform, it will cause total loss of the image.

Use of a stop, a long wash, or a clearing bath (Sodium Sulfite in water), or a mix of all 3 will prevent this stain. Going from the clearing bath into the bleach directly will prematurely exhaust the bleach.

Current negative films are not tested with a Ferri bleach. They used to be up until the mid 70s. Therefore, image stability is not known.

PE

 

[newcan1]

So if I did stop bath, then rinse, then clearing bath, then rinse, then bleach? Would I need another clearing bath after the bleach? It's worth it if it maintains the integrity of the bleach and prevents stains forming. I'm going to mix some fresh bleach to develop my test # 4 tomorrow, so it would be useful to know.

How much sodium sulfite per liter?

I really appreciate your help.

 

[Photo Engineer]

You do not need a clearing bath after the bleach. Just wash well and then fix.

You need a clearing bath before the bleach. It should be about 20 g/l Sodium Sulfite at a pH of around 7. If it is acidic, say pH 4.5, it will smell horrible but it will be a good stop and clear. Kodak used to make a clearing bath with that type of composition. It contained Acetic Acid and Sodium Acetate along with the Sulfite.

PE

 

[newcan1]

Thanks PE - this is greatly appreciated. I will use the sulfuric acid stop bath and then a brief wash. Then the 20g/L clearing bath and another brief wash before the ferricyanide bleach. My test no. 4 is Eastman Vision3 250D film, using the same developer as in my prior posts, to see if the lack of sharpness I documented is the film or the developer. If this film is unsharp, then I will eliminate the benzotriazole and see what happens. I know that Vision3 250D is capable of great sharpness.

 

[kb3lms]

I did not use a sulfite clearing bath but I believe I will in the future. With C-41 I always use a sulfite clearing bath. One time I did not and learned that lesson. You get very high DMIN and nearly unusable negatives. But I did not notice that problem with the ECN-2 film. However, I feel that the use of the clearing bath with any ferricyanide bleach is a "best practice."

PE: does the 2% Sodium Sulfite clearing bath hold for C-41 as well? I have been mixing it somewhat stronger than that but sounds like I may just be wasting sulfite.

-- Jason

 

[Photo Engineer]

A clearing bath before all Ferricyanid, Dichromate and Permanganate bleaches is virtually essential.

PE

 

[kb3lms]

A clearing bath before all Ferricyanid, Dichromate and Permanganate bleaches is virtually essential.

PE

PE, I'm sorry. I meant was the 2% concentration the correct strength with regard to C-41. Absolutely agree on the need for the bath.

-- Jason

 

[Photo Engineer]

A good C41 or RA4 stop bath should be 1 - 2% Acetic acid. If you are using one of the 3 bleach types I mentioned above, then adding 20 g/l or thereabouts, of Sodium Sulfite would be a good idea to prevent stain.

PE

 

[kb3lms]

Oh, are you saying it's OK to add the sodium sulfite to the stop bath? I didn't know you could do that and I've always done it as a separate step.

 

[Photo Engineer]

Yes, Sulfite is a normal ingredient in many stop baths so that it is a stop and clear.

PE

 

[kb3lms]

@newcan1: Was this the final formula that you ended up using?

Distilled Water 21 to 38°C (70 to 100°F): 850mL
Sodium Hexametaphosphate: 2.0g
Sodium Sulfite (Anhydrous): 2.0g
Potassium Bromide (Anhydrous): 1.4g
Sodium Carbonate (Anhydrous): 25.6g
Sodium Bicarbonate: 2.7g
Benzotriazole: 5mg
CD-3: 5.2g
Distilled Water to make
1L

Also, any thoughts on the 2 part developer?

 

[Photo Engineer]

No color neg-pos developer contains BTAZ as far as I know.

Also, the pH is critical for color to balance the 9 emulsions and therefore should be specified in any formula.

PE