Higher Contrast C41 or ECN-2 developer?

newcan1 · Jul 10, 2013

We have been discussing on another thread tweaks to an RA4 formula, and it has been established that reducing the amount of sodium sulfite and/or increasing carbonate can increase contrast in a print.

I was wondering if anyone has experimented with similar adjustments to alter contrast in C41 developing? I'm most interested to know if similar tweaks could cause an ECN-2 negative to develop with higher than normal contrast, without significant crossover, to assist in the normal printing thereof. For example, if I could up the negative contrast a bit, and up the printing contrast a bit, I could end up with a good print result. Any ideas?

polyglot · Jul 10, 2013

You can adjust contrast via development time, e.g. plus or minus 30s for about a stop push/pull. 1 stop pull on C41 makes it easier to print portraits on modern (high contrast) papers.

newcan1 · Jul 21, 2013

Push developing would make an overly dense negative, unless I under-exposed, which I doubt would be optimal, but maybe worth a try.

I was wondering what is the effect of re-developing after bleaching - so dev, stop, bleach, re-dev, bleach, fix. Also, is the normal C41/ECN2 bleach a rehalogenating bleach? Anyone? PE perhaps?

polyglot · Jul 21, 2013

newcan1 said:
I was wondering what is the effect of re-developing after bleaching - so dev, stop, bleach, re-dev, bleach, fix. Also, is the normal C41/ECN2 bleach a rehalogenating bleach? Anyone? PE perhaps?

What you're referring to is "rehal", after the rehalogenating bleach required to do this. It results in increased saturation as long as you bleach out the silver at the end. There's (there was a url link here which no longer exists) which talks about rehal for doing partial bleach-bypass.

newcan1 · Jul 21, 2013

Yes -- do you know if standard C41 bleach is rehalogenating? Or would I need to use say a potassium ferricyanide bleach with potassium bromide?

newcan1 · Jul 21, 2013

I saw the old thread - seems I would use the ferri bleach with pot. Bromide. But in addition to increasing color saturation, would a second development also increase contrast?

polyglot · Jul 21, 2013

newcan1 · Jul 21, 2013

OK well I guess that will be my experiment for tomorrow!

Athiril · Jul 22, 2013

If you want to 'double develop', it'd be developer, stop, rinse, fix, wash, ferri bleach, wash well (or sulfite bath then wash), develop, bleach, fix, wash, etc.

I added extra KBr to my C-41, to increase developing time while losing film speed at the same time, so I could 'pull' without lowering the contrast.

newcan1 · Jul 22, 2013

Athiril, putting the fix ahead of the bleach, what is there left to redevelop? I thought it was develop, stop, rinse, ferri bleach, wash well, develop, bleach, fix etc. I.e, no fix until after re-develop. I thought the aim is to rehalogenate the silver produced in the first develop, no?

newcan1 · Jul 22, 2013

Oops - Athiril - of course you are correct - disregard the last post!

newcan1 · Jul 23, 2013

Is it necessary to expose the film to light after rehal bleach?

newcan1 · Jul 24, 2013

Well I just got some interesting results. I shot some Vision2 250D film. I always modify the ECN-2 developer to use 5.2 mg/L CD3 instead of 4mg. Also, I use Calgon instead of Kodak AntiCal #4 as the latter is only available in huge quantities

This time I developed the film for 4 minutes at 106 deg F, then did the rehalogenation thing, redeveloping for another 4 minutes.

Printing the results on Ektocolor Edge, the colors were dead on accurate, with no detectable crossover, and contrast was almost to where I wanted it. (I also modified my RA4 homebrew to use 6mg/L CD3 instead of 5mg). The addition of 2ml/L hydrogen peroxide give an excellent result.

A couple of observations: The pictures are razor sharp; the redevelopment must do something to increase sharpness. But there is enhanced grain, especially in the blue color. I'm not sure if much can be done about that.

I'll probably fine tune the contrast with H202 some more, but all in all, I really like the rehalogenation/redevelopment technique where ECN-2 film is to be shot for RA4 printing rather than scanning.

StoneNYC · Jul 24, 2013

newcan1 said:
Well I just got some interesting results. I shot some Vision2 250D film. I always modify the ECN-2 developer to use 5.2 mg/L CD3 instead of 4mg. Also, I use Calgon instead of Kodak AntiCal #4 as the latter is only available in huge quantities

This time I developed the film for 4 minutes at 106 deg F, then did the rehalogenation thing, redeveloping for another 4 minutes.

Printing the results on Ektocolor Edge, the colors were dead on accurate, with no detectable crossover, and contrast was almost to where I wanted it. (I also modified my RA4 homebrew to use 6mg/L CD3 instead of 5mg). The addition of 2ml/L hydrogen peroxide give an excellent result.

A couple of observations: The pictures are razor sharp; the redevelopment must do something to increase sharpness. But there is enhanced grain, especially in the blue color. I'm not sure if much can be done about that.

I'll probably fine tune the contrast with H202 some more, but all in all, I really like the rehalogenation/redevelopment technique where ECN-2 film is to be shot for RA4 printing rather than scanning.

Are you able to scan them too? can we see a straight scan result vs a print result of the same image? I'm about to do my first run on the ECN-2 shot with an amber flash to compensate for the Tungsten (mine is 500T) and JUST today got in my 85B filter, so I'm going to go through another roll today/tomorrow and develop both, but before I do, I would like to hear advice on the full process, all the chems etc. I don't mean to be greedy since you seem to have done the legwork, but I also can't fiddle too much on my budget haha.

Thanks.

newcan1 · Jul 24, 2013

Hi Stone:

Basically I normally use Kodak's formula for ECN-2 but (1) use some sodium hexametaphospate (I can tell you how much tomorrow) instead of the Kodak anti-cal, and I up the CD3 to 5.2 mg/L. I use C41 bleach or use the Kodak formula for the ferricyanide bleach. Stop bath - if you really want to use sulfuric acid you can mix from battery acid (from Autozone), but I find that white vinegar mixed 50-50 with water does just fine. C41 fixer seems fine. I'm sure some here will castigate me for this anecdotal advice. Negatives straight processed this way on up-to-date ECN-2 stock (such as Vision2 or Vision3 or Eterna) scan exceptionally well, subject to contrast adjustment on the computer; at least as well as Portra and maybe even better.

I haven't scanned the double-developed negatives yet. They are in my darkroom downtown -- I'll bring them home tomorrow and scan some. If you want to see some scans of regularly processed ECN-2, let me know.

StoneNYC · Jul 24, 2013

newcan1 said:
Hi Stone:

Basically I normally use Kodak's formula for ECN-2 but (1) use some sodium hexametaphospate (I can tell you how much tomorrow) instead of the Kodak anti-cal, and I up the CD3 to 5.2 mg/L. I use C41 bleach or use the Kodak formula for the ferricyanide bleach. Stop bath - if you really want to use sulfuric acid you can mix from battery acid (from Autozone), but I find that white vinegar mixed 50-50 with water does just fine. C41 fixer seems fine. I'm sure some here will castigate me for this anecdotal advice. Negatives straight processed this way on up-to-date ECN-2 stock (such as Vision2 or Vision3 or Eterna) scan exceptionally well, subject to contrast adjustment on the computer; at least as well as Portra and maybe even better.

I haven't scanned the double-developed negatives yet. They are in my darkroom downtown -- I'll bring them home tomorrow and scan some. If you want to see some scans of regularly processed ECN-2, let me know.

Yes an example of each in similar light situations and similar scene would be great, I know that's not always possible but it's a start

Athiril · Jul 24, 2013

newcan1 said:
Well I just got some interesting results. I shot some Vision2 250D film. I always modify the ECN-2 developer to use 5.2 mg/L CD3 instead of 4mg. Also, I use Calgon instead of Kodak AntiCal #4 as the latter is only available in huge quantities

This time I developed the film for 4 minutes at 106 deg F, then did the rehalogenation thing, redeveloping for another 4 minutes.

Printing the results on Ektocolor Edge, the colors were dead on accurate, with no detectable crossover, and contrast was almost to where I wanted it. (I also modified my RA4 homebrew to use 6mg/L CD3 instead of 5mg). The addition of 2ml/L hydrogen peroxide give an excellent result.

A couple of observations: The pictures are razor sharp; the redevelopment must do something to increase sharpness. But there is enhanced grain, especially in the blue color. I'm not sure if much can be done about that.

I'll probably fine tune the contrast with H202 some more, but all in all, I really like the rehalogenation/redevelopment technique where ECN-2 film is to be shot for RA4 printing rather than scanning.

More contrast = higher MTF response.

newcan1 · Jul 24, 2013

Athiril: forgive my ignorance: What is MTF response?

Athiril · Jul 25, 2013

newcan1 said:
Athiril: forgive my ignorance: What is MTF response?

Modulation Transfer Function for a given spatial frequency.

http://www.normankoren.com/Tutorials/MTF.html
http://www.normankoren.com/Tutorials/MTF1A.html

Higher Contrast C41 or ECN-2 developer?

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