Blue Tint in Kodak E6 Control Strip with Fujihunt C6R Chemicals

losheng · Jan 13, 2012

Hey, guys,

Recently a bunch of us have managed to get hold of the C6R chemicals from Fujihunt that's the equivalent of Kodak's E-6 process. We developed our chromes using either phototherm or Jobo equipments. After a few initial failures with over-active reversal baths, most of the developed slides are looking very good. Just to be anal about the process, I've run the the Kodak's E-6 control strip through these chemicals, and I seemed to have hit a wall with the slight bluish tint on the LD and HD portion of the strip. This is inline with the observation that some of slides developed carried a tiny bit of bluish tint.

I have tried various means to try to correct the problems - lowering the reversal bath concentration, to slightly varying the proportion of Part A and B of the color developers, and even adding sodium hydroxide to the color developers. All these changes didn't change the result of the control strip too much - which in one way, is great news - it shows just how robust the E6 process is; but the bad news is that i am unable to hit the nail of the problem to get the TD and HD square to the same neutral gray found on the reference strip.

Just wondering if you guys have any pointers on what could be the issue here? Would adding starter solutions to the First Developer and Color Developer help?

Mark Antony · Jan 13, 2012

Hi
You've done most things correctly in order to correct this. Low p.h is the normal culprit wrt blue cast on Kodak with CR56, the cast will be magenta on fuji film with the same problem. To fix this try a 10% aqueous solution of NaOH to the colour developer.
If you've tried this (and I can see you've used the NaOH) then it could be contamination of the first developer with fixer, or even insufficient agitation (unlikely with Jobo) too little part A in the colour dev will also cause this.
One last long shot is to buy some Fuji controls as well, remember to apply the printed corrections when you compare your strip to the reference after reading on a densitometer, you could just be looking at batch variation if you just compare by eye.
Good luck
Mark

losheng · Jan 13, 2012

Thank you, Mark!

Since the solutions are all freshly mixed for each run, I can't think of a reason how the first developer could have been contamination by the fixer, or get consistently contaminated. I have tried about 10 runs now. AFAIK, the reason behind the contamination causing the blue tint is that the fixer acts as a catalyst, thereby over accelerating the effects of the first developer. So, I'm wondering if slowing down the activity of the first developer by adding the starter solution will help. In Kodak's documentation, it did list as the lack of starter solutions as a possible cause of blue tints.

I have also reduced the concentration of Part B by as much as 10% to see if it makes any difference, and amazingly it didn't. I have also added the equivalent of 4ml per litre of 5N NaOH, and again, it didn't lift the tint by too much visually. This is pretty frustrating. I'm going to try raising the amount of NaOH even more. I don't have a densitometer, and I think it's a good idea to get one just to be methodical about the analysis.

This whole process is so robustly consistent that it seems nothing I do changes anything. I'm going to try adding salt, soya sauce and ketchup, and i bet the result is still going to come out the same!

Getting the Fujifilm controls is a good idea, but it's pretty hard to find. The usual online stores don't seem to stock it. Even the Kodak control strips are hard to come by these days. So far, only Kull and Company has it listed. I'm going to ping them and see how it goes.

Thanks for the reply!

mts · Jan 13, 2012

Are you including a sulfite-contining stop bath after the first and second developers? You must use different (separate) stop baths. A good rinse following the stop bath is also a good idea. You should measure the pH of the color developer and set it to specification (11.5 if I recall correctly, and 10.0 for first developer, but check me on those numbers).

Photo Engineer · Jan 14, 2012

Kodak and Fuji suggest different times in the first developer for their films. Are you using the correct recommended times?

PE

losheng · Jan 17, 2012

Hi, mts, PE, thanks for the suggestions.

I'm using Phototherm that has an built-in program for E6. There's a wash step after the first developer, but it uses water. I'm not sure it it is at all possible to introduce a separate stop bath.

As for the development time, I follow the instructions of the C6R faithfully. If anyone is interested, a copy of the instruction is here.

Do any of you think that starter solutions might help? In one of the Kodak documentation for E6 troubleshooting, the lack of starter solution is listed as one of the possible causes, and that's pretty much the last option that I have yet to try.

Photo Engineer · Jan 17, 2012

Lack of starter and the wrong 1st developer time are both possible problems.

PE

losheng · Jan 17, 2012

Photo Engineer said:
Lack of starter and the wrong 1st developer time are both possible problems.

Hi! With regards to the development time - should i try shortening or extending the development time?

I have gone ahead and place the order for the starter solutions for both the first developer as well as color developer. I will give those a try as soon as the stock arrives.

Photo Engineer · Jan 17, 2012

Read the Kodak and Fuji documentation regarding 1st development times.

PE

abbandon · Jan 28, 2012

losheng said:
Hi, mts, PE, thanks for the suggestions.

I'm using Phototherm that has an built-in program for E6. There's a wash step after the first developer, but it uses water. I'm not sure it it is at all possible to introduce a separate stop bath.

As for the development time, I follow the instructions of the C6R faithfully. If anyone is interested, a copy of the instruction is here.

Do any of you think that starter solutions might help? In one of the Kodak documentation for E6 troubleshooting, the lack of starter solution is listed as one of the possible causes, and that's pretty much the last option that I have yet to try.

Are you sure your chemistry is in date ? I ask because if you are following those instructions faithfully are you aware that Conditioner and Stabalizer were replaced some years ago by Pre Bleach 2 and Final Rinse.

I would love to provide a link to the Fuji Hunt current E6 Technical manual but the forum anti link protection really is comprehensive and I have wasted half an hour of my life already on alternatives that would usually work so the best I can do is say google for TB E6_E13_09-11.pdf its the first and only result I get.

I would also recomend you google for TIS Replacements for E6 Kits

The quote below is from it

Please note that the use of Pro6 First Developer and Pro6 Colour Developer as working Tank olution requires the use of special starter solution for each developer. This is not optional; you will not achieve a satisfactory E6 process without use of the correct starters.

An error has occurred abbandon! You must have 5 posts in order to post links. Your current post count is 0.

Any way that could be a bit more selective as in it is preventing the link in the orginal post

losheng · Jan 29, 2012

abbandon said:
Are you sure your chemistry is in date ? I ask because if you are following those instructions faithfully are you aware that Conditioner and Stabalizer were replaced some years ago by Pre Bleach 2 and Final Rinse.

Thank you so much for the information. Incidentally I have seen the same doc regarding the Pro6 system of chemicals. This particular document is hosted by Fujifilm Europe, so I wonder if the Pro6 system is simply the European designation of the same C6R chemicals that i have. I'm very certain that the chemicals is fresh, since it is made right here in Singapore, in an industrial area not more than 10 miles from where I live. The local Fujihunt manager has provided me with the following processing document:

Fujihunt C6R Chemical System

Development timing for each step is exactly the same as the Pro6 system.

In any case, the use of the starters is the last option that i have yet to attempt. I have ordered a set of starters that I will pick up tomorrow, and I will run another test strip through it and report back the result.

ls

losheng · Aug 7, 2012

Hi, guys, after more than hundred rolls of experimentation and tuning, I thought I will report back the findings, so that if there's anyone else working with the Fujihunt chemicals, he/she can learnt from my failures:

1. yes, definitely use the starters. I find the amount of First Developer starter adds a yellowish hue to the slides. Too much, and the hue begin to appear even in the transparent area (Dmin).

2. besides the starters for both First Developer and Color Developer, it's important to dilute down the reversal bath. Optimal dilution is 60-80% of the recommended concentration.

3. dilute down color developer by 10-15%.

With these changes, the processed slides have very beautiful and neutral tones. However, they are still not within the control-limits of the Kodak E6 Control Strips. I've getting very good support from Fujihunt Europe. With one-shot processors like the Phototherm, there's a lot of trial and error to get things spot on. The good thing is that Phototherm is incredibly consistent, as verified by measuring control strips from different runs of the same parameters.

I can definitely use some help with interpreting the densitometer results. If anyone of you have experience with it - please let me know! I'm more than happy to post the results online!

ls

Photo Engineer · Aug 7, 2012

Please post the curves from the control strips. I have had the experience of judging them.

PE

losheng · Aug 7, 2012

Great! Ok, here are the results from my last 2 runs:

<https://docs.google.com/spreadsheet/pub?key=0Auimm-WFQBCodENOZm5oNzZuVEg0U1VMZEdGTGlYM2c&single=true&gid=0&output=html>

The densities for both Color and Speed tend to be on the high side compared to the reference. Does it mean that increasing the First Developer processing time will bring the difference down?

Also, clearly the blue readings tend be off from the other 2. Do you have any suggestion on how to reign in the blue readings?

Thanks!

ls

Photo Engineer · Aug 8, 2012

Do you have a reference value? That would help.

Also, that Dmax looks odd to me. They are all way too low. If it is indeed Dmax, then the values should be in the range of 3.0 - 3.5.

PE

losheng · Aug 8, 2012

These are the deltas from the aim values. For the absolute values, I'll need to retrieve them from the densitometer when I get back to the darkroom. Would these difference values be enough to offer a clue to the problem? My understanding is that the process is within control limits when all these numbers are less than 0.1 - is that correct?

Photo Engineer · Aug 8, 2012

I should have realized that it was a delta value. Shame on me!

It appears that the Red speed is slightly high and Blue is just about right on. If that is the case, then the image should appear yellowish unless the contrast of the layers is very much off due to crossover.

You see, as a layer speeds up in a reversal film, the less density it contributes to the image or the lighter it gets. For example, to have a blue tint, you need lower red speed and green speed giving you more cyan dye and magenta dye.

Bottom line, the numbers make sense for a problem, most likely some sort of development problem, but there is not enough data in the control strip information to tell. Sorry. The high yellow Dmin does suggest underdevelopment in the First Developer.

PE

losheng · Aug 8, 2012

Greg: let me go back to plot the data on the form and have it put up here. Looking at the form, it appears that the tolerance for each of the key measurements is to be within 0.04, and anything between 0.04-0.1 is considered within Control Limit, and anything above that is out of control limits - am I right?

PE: Thanks for the feedback. What are the control limits? I think by extending the first developer time, I can bring the average Color and Speed values to be closer to the aim point. However, clearly the spread limit between the 3 colors is a bit too wide. Do you have any idea what factors control the color spread?

Thanks, guys!

Photo Engineer · Aug 8, 2012

You have to get the delta values from EK or Fuji.

Sorry.

Pe

losheng · Jul 17, 2017

Just to provide an update after several years of working on this - a few things have helped to narrow the spread of the values:

1. Yes, the use of starter solutions for the First Developer and Colour Developers is critical
2. Use 60% of the recommended REV values for one-shot processing
3. This one took us quite a while to discover: it's important to leave the freshly mixed solution standing for 30 mins before processing. When we didn't do that, occasionally we got what it looked like an over processed film. This one might be specific to use of one-shot processors like the Phototherm.

Hope it helps!

Blue Tint in Kodak E6 Control Strip with Fujihunt C6R Chemicals

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