Color Developer Quest

[newcan1]

After much research, I found a really good C-41 developer formula right here on APUG, and when I use it, I find that I can scan my negatives and need very little color correction.

Not so, unfortunately, with the formula I am using for ECN-2 films. The developer I am using for that is found here:

(there was a url link here which no longer exists)

Unlike C41, which has been the subject of much experimentation, there really aren't too many unofficial developers published for ECN-2. The above was really just a slimmed down version of Kodak's published formula, by removing certain chemicals that are hard to find or very expensive.

So here's the deal. The negatives develop to a good density, commensurate with the ISO of the film, but regardless of the particular ECN-2 film I use, a straight scan always comes out with a green cast. This can be corrected on the computer, or if i print analog, the cast can be corrected by filtration changes on the enlarger. There is no serious color cross-over or anything, just that the images always are a bit green if not corrected.

Because this happens across film stocks, my assumption is that the developer is not developing each layer correctly. It is perhaps developing the red and blue layers less than the green layer.

I am not a chemist -- but if I wanted to tweak the above formula, what things would tend to move the development in the right direction? I am hoping Photo Engineer or a similar inordinately knowledgeable peson could give me some things to try. I don't want to buy overly exotic chemicals, but I would love to end up with a formula for developing ECN-2 as successfully as C41.

 

[Photo Engineer]

Kodak has freely published the ECN2 formulas for all to see.

PE

 

[newcan1]

Hi PE - I realize this - and the formula I linked to in the previous APUG thread was an exact copy of a published formula minus certain hard to get chemicals (such as Kodak anti fog #4, Kodak Antifoggant AF-2000). To restate my original question, I would love to know what those chemicals do, and whether there are any non-proprietary substitutes that I could try.

 

[Photo Engineer]

Well, first, the formulas you refer to are not exactly the same as those published by EK, and I suspect that the difference in KBr level (an antifoggant) is there to compensate for the absence of AF2000 (another antifoggant). However, this change probably depresses edge effects and thus may make the film less sharp. So, IDK what to say to you except that it is the old Key + Lock situation. The film was designed for the developer and vice versa.

I'm sorry but someone has posted the name for AF2000 here somewhere. OTOH, you might try the following:

Benzotriazole, Phenyl Mercapto Tetrazole, or 5 nitro benzimidazole nitrate. The first two are available from the Formulary, which is where I got mine. I would use them very sparingly and the tests will have to be Trial and Error.

Also, you might note that the stop bath for ECN2 is dilute Sulfuric Acid. So, the reference you cite is not entirely correct, as I said. And, that is why I referred you to the original by EK first for starters.

PE

 

[newcan1]

Thanks PE! I have benzotriazole, so from what you say, maybe I should do a little trial and error with that and follow the Kodak formula for the amount of Potassium Bromide? Actually, I think the Kodak formula uses NaBr. I have KBr. Maybe the change in amount for the formula I am using is an adjustment for different molecular weight? I guess I will have to figure out what the correct amount of KBr would be, if indeed it is a valid substitute.

Should the addition of antifoggant affect the overall color balance?

The other missing ingredient is Kodak anti-calcium no.4. I am using distilled water, hence no calcium, but does this chemical otherwise affect performace, e.g., by affecting pH? Should I try adding a little Calgon, which I have on hand?

Finally: does the composition of the stop bath affect color balance? I just used a b&w stop bath (acetic acid based) followed by a rinse before bleaching. I do have some sulfuric acid on hand, is that likely to affect color balance?

I don't mind a little trial and error - I have probably enough ECN-2 stock at this point to last a lifetime.

And I want to thank you for your comments in this and other threads - you are certainly a wealth of knowledge for which I am very grateful!

 

[newcan1]

Also PE, here is a post in which AF-2000 is named:

(there was a url link here which no longer exists)

It seems from the discussion that it may not do much at all, so its absence may not explain my somewhat green bias. I'm beginning to wonder if the improper stop bath may be more of a cause? And I still have to figure out if Kodak Anti-Cal 4 is a big deal. Kodak's minimum quantities for this are huge and it's quite expensive. The AF-2000 on the other hand is not prohibitive but the minimum is 2x5L - rather a lot.

 

[Photo Engineer]

For Antical #4 use either Quadrofos or Sodium Hexameta phosphate. NaBr or KBr can be used as long as one compensates for the molecular weight differences between Na and K.

Sodium Nitrobenzene sulfonate is an antifoggant, and all antifoggants affect color balance slightly. Each one is different.

PE

 

[newcan1]

OK - thanks - sounds like we have a plan. I will use sodium hexametaphosphate and benzotriazole as I have them on hand, and see what happens! Does the composition of the stop bath affect anything? I guess that's the one outstanding question - I had been using acetic acid instead of sulfuric.

 

[Photo Engineer]

What do you mean "we"?

Anyhow, Sulfuric Acid would not have been used if Acetic Acid was acceptable. There is some benefit from Sulfuric Acid, I am sure, but since the MP product team was separate from the Pro and Consumer projects, I never interacted with them and thus don't know.

PE

 

[newcan1]

Interesting -- you know, the rinse after my acetic stop bath did look a bit pink, almost like there was still some CD-3 in there. Maybe acetic acid just doesn't kill it, but then RA4 stop bath is acetic, isn't it? Carry of developing agent into the ferricyanide bleach might cause a greenish cast, n'est-ce pas?

I will dig out my sulfuric acid and maybe do a test film tomorrow.

 

[Photo Engineer]

No acid will kill CD3 or CD4 for that matter.

The nature and effectiveness of the stop bath depends on the developer and the emulsion(s) being processed. Carryover of developing agent into a bleach is a very very bad thing. We used a good wash before the bleach and we also used a clearing bath of Sulfite to clean up the CD4 or CD3. It apparently is not needed here. At least not with Sulfuric Acid.

PE

 

[newcan1]

Interesting....I will pay more attention to the wash cycle between dev and bleach. I don't have a problem with C-41/CD4; there I am using a Sprint Systems stop bath which is really for b&w but I think is a buffered acetic acid (maybe buffered with sodium sulfite, I don't remember).

I have mixed a batch of ECN-2 developer with calgon and benzotriazole, if I have a moment tomorrow I'll shoot a test roll and develop and see what happens.

 

[newcan1]

I have shot a roll of Fuji Eterna Vivid 500T and will develop it in my test soup tomorrow.

But one thing is bugging me. The official formula calls for 4g CD-3 per liter. That just looks low to me, comparing with C-41 which uses CD-4 at about 5.2g/L. The ECN-2 replenishment version, however, calls for 5.2g/L CD-3 which just sounds more right to me. I may increase the CD-3 in my test batch a little, to see what happens. The ECN-2 "fresh tank" version is presumably designed for large tank, roller transport processors rather than my little developing tank. I'm guessing that my greenish bias could be a result of not enough developing agent?

 

[Photo Engineer]

Color developing agents can be used at lower concentration than B&W developing agents. They are effective in the range of 2 - 10 g/l and 10 g/l is on the very very high side.

If you got your figure from an EK publication (as we discussed earlier) then it should be correct. Higher levels will give higher contrast, shorter latitude and more fog. IDK what your green bias was due to, but I assume that you checked the pH, right?

PE

 

[newcan1]

I checked the pH, but only crudely, with a test strip. It was North of 10 and south of 11.

I'll keep the CD-3 at 4g/L as published and see what happens. I guess that otherwise, I'll have way too many variables - as I already have now, with Calgon and benzotriazole! Could be an interesting experiment. I will probably develop the negs tomorrow and scan tomorrow evening.

 

[newcan1]

Well test 1 turned out to be a failure. I used 2g/L of sodium hexametaphosphate instead of Kodak anti-cal 4, and 500mg/L of benzotriazole instead of AF-2000. I think it is the latter that let me down - there was hardly an image on the film, it was so pale. Even the orange mask seemed oddly pale. I will try again, with maybe 50mg/L benzotriazole. If that doesn't so it, I will have to reach out some more and ask what could be causing the red layer of the film to be under-developing (and possibly the blue layer also, as the cast is greenish). I am still tempted to up the amount of CD-3 to the amount used in the dev replenisher (5.2g instead of 4g).

PE, you asked if I checked the pH of the developer. What effect does pH have on color cast? If pH is too low or too high, what happens to color balance? Maybe I should get a pH meter for greater accuracy as right now I only have test strips.

 

[Photo Engineer]

Yes, 10 - 50 mg/l is more normal.

The pH has a profound effect on contrast, fog and speed. They all usually go up with pH.

PE

 

[newcan1]

OK well I guess I really overdid the benzotriazole! I'll shoot another test roll tomorrow and develop it in the next day or two. Many thanks for all your advice, PE!

I may sneak in a little extra CD-3 because even the small amount of benzotriazole is likely to reduce speed a little.

 

[Athiril]

What do you mean "we"?

Anyhow, Sulfuric Acid would not have been used if Acetic Acid was acceptable. There is some benefit from Sulfuric Acid, I am sure, but since the MP product team was separate from the Pro and Consumer projects, I never interacted with them and thus don't know.

PE

I was assumed this to be the handling, usage, and cost of bulk sulphuric acid over acetic acid. You also said Benzotriazole shouldn't be used in a colour developer solution previously.

Interesting -- you know, the rinse after my acetic stop bath did look a bit pink, almost like there was still some CD-3 in there. Maybe acetic acid just doesn't kill it, but then RA4 stop bath is acetic, isn't it? Carry of developing agent into the ferricyanide bleach might cause a greenish cast, n'est-ce pas?

I will dig out my sulfuric acid and maybe do a test film tomorrow.

This is normal.

I have shot a roll of Fuji Eterna Vivid 500T and will develop it in my test soup tomorrow.

But one thing is bugging me. The official formula calls for 4g CD-3 per liter. That just looks low to me, comparing with C-41 which uses CD-4 at about 5.2g/L. The ECN-2 replenishment version, however, calls for 5.2g/L CD-3 which just sounds more right to me. I may increase the CD-3 in my test batch a little, to see what happens. The ECN-2 "fresh tank" version is presumably designed for large tank, roller transport processors rather than my little developing tank. I'm guessing that my greenish bias could be a result of not enough developing agent?

The higher amount is for replenishment, replenisher is less diluted typically than seasoned solution, seasoned solution loses the developer agent and sulphite and etc over usage, you wouldn't just add tank solution strength.. needs to be a bit stronger to average it back out to tank solution/seasoned strength.

Also in the ECN-2 formula, there are discrepancies in amounts to account for losses due to aeration and mixing of the CD-3 and sulphite.


The amount you are supposed to mix up is 5.5g/L for replenisher and 4.0g/L for tank solution, the 5.2g/L figure is what you typically should get after mixing and aeration losses.


Developer carryover into a sulphuric acid stop bath generates sulphur dioxide gas, so be careful about that.

 

[newcan1]

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....!

 

[newcan1]

I am wondering.....I used an 85B filter instead of an 85A (as I don't currently have an 85A) -- perhaps that is the reason for the cast?

 

[kb3lms]

Hi newcan,

I've just started working with ECN-2 myself using 5207 250D Vision3. For developer I used the formula in the "ECN-2 For Pictorial Use" article. Once I have some good scans without other peoples children in them I will post some results. I've only processed one roll so far, but regarding color cast, I didn't notice any overall cast at all. But I can say that the 5207 tends towards a bluish cast on underexposure, and it doesn't take much, like I find when using Ektar. Since the stocks are supposedly closely related I guess that's not a big surprise. The day this roll was shot was mostly overcast with some breaks of full sun. The shots taken in full sun seem to be right on, shots when overcast are a little bit blue for my taste. The other comment I have is that the film does seem to like green in that green grass is GREEN. But skin tones and such were perfectly normal.

-- Jason

 

[newcan1]

Thanks for the info, Jason. I used the same formula for some Vision 3 250D, EXR 200T, Vision 2 500T, to name a few. I was not entirely happy with the formula. Looking at the pics I posted a couple of posts ago, I am thinking that my tweaks to the formula may be moving in the right direction. I should receive an 85A filter in the next few days and will re-shoot a test roll with that. I'm shooting another roll of Eterna Vivid this afternoon still with 85B filter) and should have the results today or tomorrow. If I get good results I'll post the formula-in-process here.

I don't think I had the same results as you with the Vision 3 250D. I shot some rolls last fall, and they had a slightly green cast which was easily correctable on the computer. I was also able to color correct in the enlarger, and made a few good prints. But my goal is to be able to scan and not have to color correct, which is more or less the case with my C-41 processing.

Do put up some of your pics when ready and we can compare notes. I'm particularly interested in uncorrected scans (like the one I posted above).

 

[Photo Engineer]

Go here for some comparisons of ECN2, Fuji and C41: Dead Link Removed

BTAZ is very powerful and affects color balance. Even at 20 mg/L you see effects here. Probably 5 mg/L or thereabouts would be more useful. And the difficulty of balancing is why I do not go around suggesting its use in color. Most color neg-pos systems rely on Halide salts to do the necessary antifogging.

The sulfuric acid may be used to insure quick stopping action for good uniformity. IDK for sure. It is different though and would not be used unless it were necessary.

PE

 

[newcan1]

I have seen that comparison before, PE - it is remarkable, but no surprise. I have found the Kodak Vision series stocks have the most amazing latitude.

Yes re: benzotriazole, I think my 20mg still caused an unacceptable loss in speed. I don't know what effect it has on color balance but maybe I will learn by reducing the amount. I will try 5mg/L this afternoon. I just sense that having a smidgeon of it in the mix will be helpful.

The sulfuric acid definitely seems to do something different. there is no pink hue to the wash afterwards - I think it really does work better than acetic acid in this case.

Finally (for now): PE, you have a thread here on how H202 can enhance contrast in RA4 printing. I tried that and it works very well. I was wondering if that is unique to RA4 or whether it may also raise the contrast of film? I ask because RA4 is CD3 based, like ECN-2 is.