ILFOCHROME HOME-BREWED BLEACH

[hrst]

Now hrst is working out a home brewed bleach - a good news.

Brooks is, in fact; I'm just testing his stuff . But it seems quite good.

 

[Wayne]

This is encouraging.

 

[Stephen Frizza]

I've got the first results now, and I can say that;

This stuff really seems to work. Brookse has done good work. I have perfect black and white, vibrant colors and only little crossover, and quite easily.

There is only a very tiny bit of silver for blix to remove after the dye bleach and fixer.

The very first test sheet was great. No problems arised yet.

I'll continue to work with this and report when I have more specific results.

I'm working with trays.

Hello I have been finding following this post interesting I am curious are all your tests as to how well the process is working done via making a print and being happy with the result or are u actually running Ilfochrome control strips through your chemistry and comparing the results of a control strip to the manufactures? if not will u be doing this once your established and happy with the soup your making? i would love to hear further about this.

 

[brookse]

Stephen.. I must admit I was totally taken aback by your control strip post. Over a number of years I have been scouring the web pages of most US ilfochrome distributors, and have never seen any mention of process control strips, nor any manual which might accompany them. After your post, I immediately did a google search, and attempted a search on the Ilford site, with very little to show for it. The only google hits were for P4 and Ilford Micrographic film pdfs, which are quite useless. There was one vague illusion to P3X control strips in the specification section for P3X on the B&H site. This site would have to represent one of the top US distributors...but never has there been a stand alone entry for process control products. I believe that Wynit and Freestyle are dittos. Having used the classic Kodak Z-manuals for process monitoring, my main question to you is: Does such exist for Ilfochrome? If so, does the manual demonstrate common sensitometric deviations from the norm, and definitive corrective moves, specifically for each case. This information would be quite valuable. However, the initial excellent work by Hrst (Thanks 1,000,000 Hrst!) is being conducted with a formula which keeps active components to a bare minimum....but he is going to concentrate on capacity issues as he goes along. So, if the process control that you practice down under involves mainly replenishment rates etc. then its a bit premature. Another question... Exactly how do you use the dark blue spot on the right of the strip? What exactly do you do, if densitometry here shows deviation? Does it involve use of "conditioner" or "additive" ? Your input will be greatly appreciated!

 

[Stephen Frizza]

Stephen.. I must admit I was totally taken aback by your control strip post. Over a number of years I have been scouring the web pages of most US ilfochrome distributors, and have never seen any mention of process control strips, nor any manual which might accompany them. After your post, I immediately did a google search, and attempted a search on the Ilford site, with very little to show for it. The only google hits were for P4 and Ilford Micrographic film pdfs, which are quite useless. There was one vague illusion to P3X control strips in the specification section for P3X on the B&H site. This site would have to represent one of the top US distributors...but never has there been a stand alone entry for process control products. I believe that Wynit and Freestyle are dittos. Having used the classic Kodak Z-manuals for process monitoring, my main question to you is: Does such exist for Ilfochrome? If so, does the manual demonstrate common sensitometric deviations from the norm, and definitive corrective moves, specifically for each case. This information would be quite valuable. However, the initial excellent work by Hrst (Thanks 1,000,000 Hrst!) is being conducted with a formula which keeps active components to a bare minimum....but he is going to concentrate on capacity issues as he goes along. So, if the process control that you practice down under involves mainly replenishment rates etc. then its a bit premature. Another question... Exactly how do you use the dark blue spot on the right of the strip? What exactly do you do, if densitometry here shows deviation? Does it involve use of "conditioner" or "additive" ? Your input will be greatly appreciated!

I am also surprised how little information is on the web about ilfochrome control strips however yes there is a massive amount of information supplied by the manufacturer regarding these control strips. All the information I have ever seen comes nicely supplied in hard copy. Three large binders (hundreds of pages) full of important information relating to the control strips how to measure them and what their readings mean and how to correct the process for hundreds of sensitometric deviations. This information delves into when first tanking up, use and replenishment info, conditioner info, additives, issues with temp, time and specific gravity etc...

The mysterious blue dot at the end of the control strip is for measuring masking

While we are on the issue I am curious how does the specific gravity of your home brew compare to the commercial product?

 

[Photo Engineer]

Unfortunately, most people do not have hydrometers (http://en.wikipedia.org/wiki/Hydrometer) hanging around the house to measure specific gravity. This is probably unimportant in this "home brew" work anyhow as the formulas are quite different than the originals, I think.

I have found two possible sources of Sulfamic acid though. One is marked 100% pure Sulfamic Acid and is sold as Etching Acid Crystals to be used in preparing concrete floors for painting or other coatings. The other, which I have not been able to verify except by hearsay is the cleaner for water stills. It is the acid cleaner used to remove scales from still condenser that accumulates over time when you distill water.

PE

 

[Ray Rogers]

Stephen.. I must admit I was totally taken aback by your control strip post. Over a number of years I have been scouring the web pages of most US ilfochrome distributors, and have never seen any mention of process control strips, ... Another question... Exactly how do you use the dark blue spot on the right of the strip?

What did I miss? Have you guys been talking off list?
If you are unaware of any control strips, how do you know about the dark blue dot?

Is the answer in this: There was one vague illusion to P3X control strips in the specification section for P3X on the B&H site.

???

 

[Stephen Frizza]

What did I miss? Have you guys been talking off list?
If you are unaware of any control strips, how do you know about the dark blue dot?

Is the answer in this: There was one vague illusion to P3X control strips in the specification section for P3X on the B&H site.

???

I posted a picture of an ilfochrome control a few weeks ago please see
(there was a url link here which no longer exists)

 

[Ray Rogers]

Thanks Stephen..

 

[brookse]

With reference to the Ilfochrome PQ B&W developer, and its replacement by a commercial MQ product such as Dektol(diluted), some previous thread posts are relevant:

bwfans(above)includes a reference from PSA journal. But of course, only the first page is revealed at no charge. http://findarticles.com/p/articles/m...8/ai_11882356/

Nevertheless one statement from that page seems to jump out:

"Is there any trade-off [using Dektol]? Yes. You lose over a stop of sensitivity and considerable change in color balance as shown by the two examples."

and there is the following APUG reference:
(there was a url link here which no longer exists) ......which includes

A) an experimental entry by Lopaka:

"Printing from a known image, one 8x10 each developer variant, same enlarger height, f-stop, time and filter pack. All from the same box of paper. All processing done on JOBO CPP-2 once and dump. Bleach and fix drawn from same working solutions mixed for the session. Alternate developers run at same time/temp as Ilfochrome dev. Where there is ref to sodium thiosulfate, it is crystal obtained from Digitaltruth, what looked to be approx 1/4 teaspoon weighed out at 0.8 gram on lab scale accurate to +/- 0.1 gram. Where used, it is at 0.8g/litre of working solution dev. Control print made with fresh Ilfochrome developer in same session.

1) Dektol 1:3 - print ok density/contrast with some yellow shift, looks to be correctable with filter change

2) Dektol 1:3 w/sodium thiosulfate - same as (1) but a bit lighter, like somewhat overexposed

3) Ilford Warmtone 1:9 - almost a match for (1)

4) Ilford Warmtone 1:9 w/sodium thiosulfate - pretty good match for (2) "

and B) An entry from Mmerry:

"I've had some success with Dektol 1:1 and ~1/4 tsp hypo/liter. The print is a bit duller than I'd expect, but that may be due to me trying a new process Difficult for me to tell what is my fault, the fault of older paper and what is the fault of the developer mix. As noted above, dektol without the hypo introduces a yellow shift I found hard to correct for. I'll be doing more extensive testing in the upcoming months."

All of the above refer to a major color shift with Dektol. Two of them define it as a yellow shift, and we can infer that this is likely the case with or without hypo. However, only in the last reference do we have the possibility that the yellow shift may be "hard to correct for."

Based on the results Hrst has obtained so far, I do not believe we are suffering from any major, problematic color shifts using the divided developer. Furthermore, the theoretical increase in yellow/red saturation, due to reduction of parasitic blue absorbtions by both the magenta and cyan dyes, seems indeed to be induced by the inclusion of hypo(even if scanning may exaggerate the effect slightly).

Hrst's result, also at 0.8g hypo/L, is in contrast to Wayne's entry in the above thread:

"I came across one of the old divided developer formulas that used to work, back in the day (ie before my day). They only contain 1/8 teaspoon of hypo/liter. I tried quite a few using that quantity. I never had any troubles using that amount of hypo (they just didnt do much for contrast), so you might want to try that. Or you can derive your own optimal quantity from testing. Have fun."

 

[Wayne]

I'm not sure which part of my statement conflicts with Hrst's results, but I'm not keeping close track either. All I meant was that divided developer no longer has much effect for contrast control, and it used to before I started chromes in the mid-late 90s, and that the amount of hypo is not critical, eg 1/4 or 1/8 t should work (but see PE's earlier comments on that, I am not any sort of chemist).

 

[Photo Engineer]

Too much hypo or variable hypo can cause variable contrast and dmax in the yellow (top) layer. This can extend to other layers depending on level.

Just wanted to be clear.

PE

 

[Dr. no]

Any progress?
Any good kitchen recipes?
I ran a batch from an old kit this week, the first third of the run was good, but then the bleach seemed to fatigue and got bad really quick (both with fresh and "semi-replenished").

 

[hrst]

I started experimenting with developers, trying to get rid of that red-cyan crossover, but it seems it can be quite a difficult task, at least for me :rolleyes:. By adding more bromide, I've been able to decrease the red-cyan crossover but it changes to magenta-green crossover.

I've found that thiocyanate (KSCN or NaSCN) can give quite a nice masking effect that lowers contrast and gives a boost in shadows.

 

[Dr. no]

I've been looking for phenazine and quinoxaline--various forms are available (or at least advertized) by some supply houses at various prices that make random experimentation less attractive.
A couple questions:
1. which forms of these are suitable (or best) for bleach?
2. better sources?
3. is the catalyst actually consumed in the process (if so, it should not be called a catalyst!) or is the really low pH lost--in other words, would replenishing the acid restore the activity?

The last I should be able to check for myself, but I didn't think about it in time last time I ran a batch.

4. Since the P3 components are available, at least putatively, has anyone tried using the bleach with Dektol and regular fix?

 

[Photo Engineer]

I have a 1g sample of Phenazine from Spectrum that just arrived. Due to the extremely hot weather, I have not done any experiments with it. I hope to get a sample of the Quinoxaline soon.

They are true catalysts and are not consumed in the reaction. The dye is reduced and the Silver is oxidized. If you use Sulfuric Acid, the reaction forms two Amine fragments which form a salt with the acid and the Silver forms Silver Sulfate.

PE

 

[Dr. no]

So, adding a little H2SO4 might prolong the usefulness of the bleach? (Linear kinetics on the catalyzed reaction? Increase time with further dilution of the reagent? Reaction to precipitate out the salts? so many interesting questions...) Aim for pH of 1?

 

[Photo Engineer]

I suggest reading some of the patents on Dye Bleach granted to Ciba in the 60s and 70s. There are dozens of formulas that use many different acids. The pH is generally less than 3. IDK if just adding acid will "replenish" the bleach because Silver Sulfate is formed and dissolves to some extent in the bleach rendering it less capable of bleaching more Silver metal.

PE

 

[TimmyMac]

4. Since the P3 components are available, at least putatively, has anyone tried using the bleach with Dektol and regular fix?

And also, does the bleach in the P30 kit have extra capacity (ie. does the limiting factor in the capacity of the kit have to do with the fix/developer?)

 

[brookse]

The pool of acid in Ilfochrome bleach is quite large. As the catalyst is indeed regenerated in the process, the major cause of exhaustion involves loss of the silver ligand (I-) which drives the equilibrium toward dye fragmentation. Loss of the antioxidant will also lead to aerial oxidation of the ligand. There is however another major consideration: When the catalyst is used alone in a bleach composition (especially with the very active phenazines), the dye destroyed is super-proportional to the amount of silver present. The result is an image which is VERY high in contrast. The same super-proportionality exists in chromogenic developers such as the E-6 color developer. Thus, the need for citrazinic acid as a competitive coupler to reduce contrast in E-6 becomes obvious. Ilfochrome bleach utilizes a competitive oxidant which will remove silver in the same fashion as ferric-edta, WITHOUT reducing the dye. This simultaneous competition allows a lower contrast image to be obtained, along with the removal of ALL SILVER at the conclusion of the bleach treatment. Therefore, another major cause of bleach exhaustion would be decreasing concentration of the competitive bleaching agent.

 

[Photo Engineer]

Strictly speaking, Iodide is not a ligand. It will form a true salt with silver ion. It is not ideal in that it forms the Silver salt, forms HI and is oxidized to the Iodate. I am not aware that it is used in the modern bleach due to the difficulty of fixing out AgI. Improperly fixed Ilfochrome prints show yellow highlights of unfixed AgI, and all prints kept over a long period of time have a mild residual acidic odor even with extended wash times.

In addition, Ilfochrome uses a patented multilayer structure to reduce contrast.

In traditional Ciba bleach, it contained Sulfuric Acid which forms the soluble Silver Sulfate during bleaching and thus the bleach acts in some regards like a blix. The newer bleach uses sulfamic acid which also forms a soluble salt with Silver ion.

PE

 

[Dr. no]

Actually, the currently-shipping, all-liquid kit is back to sulfuric. The prior liquid/powder kit had sulfamic.

 

[brookse]

Yes Dr. No....you are correct. Also, iodide and/or iodide-bromide mixtures have been ubiquitous in Cibachrome and Ilfochrome formulations as the silver salt-formers. Thus, given the low solubility product of AgI, I do not believe that silver sulfate has anything but a fleeting existence. Highlights are always yellow (AgI) post-SDB and high concentrations of ammonium thiosulfate are needed to fix quickly. The internal masking system does reduce contrast slightly, but its major function is to correct for unwanted dye absorptions. There is most definitely further contrast control via the aforementioned competitive process in the SDB bath itself.

 

[plus]

Hello,

I'm an italian professional printer; I'm working with my friend brooks to his ilfochrome home brewed system and I would like to let you know that first results are GORGEUS !

I invested my time and some money in this project but no regret at all. We started from fuji velvia 50, one of the hardest slide to reproduce with a proper color balance due to known crossover problems (cyan highlights, magenta shadows). The first results are so exciting that we decided to go deeper trying not only to make it a real alternative to ilfochrome but also improving it.
In fact we are going to start right now the "fine tuning" step; one of the most interesting aims of this step is modulating the contrast grade so that you can pair it with the kind of paper you are using (clm.1k or cps.1k) building some kind of "chemical contrast reduction mask".

Thanx brooks for giving me the right incentives to keep on being so excited in my "beta tester" position...


cheers!
plus

 

[Wayne]

Good to hear it...looking forward to hearing more news on this.