Pyro / Catechol paper devs

[Tom Stanworth]

Hi,

I have seen a few refernces to these PAPER devs here and there and would like to know more about their qualities with regard to image characteristics. Dont you find messing about with prints sloshing about in trays with pyro a little scary! I am happy when it is locked in a tank, but we have all had a bit of splashback in paper processing. Are the concentrations lower for print pyro type devs? Most of all, do the prints look 'different' and if so, how? Do they have any sort of compensating effect up the scale as in the neg devs??

Cheers Tom

 

[Francesco]

Tom, all my AZO contacts are developed using a catechol paper dev and Neutol WA. Lovely tonal rendition and control of highlights. I would characterize it as mid- to high contrast in effect, which is why it typically is the second dunk in my procedures. I love it with AZO. As far as I am concerned it beats my Amidol developed prints and is more convenient - I no longer need to have powdered chemicals around the house as they come in a liquid kit form.

I always use Nitrile gloves and I do not slosh my prints in the trays - I use my gloved hands to make sure the paper is under water and then I leave them lying there until their time is up.

 

[Tom Hoskinson]

All developing chemistry should be handled with good chemical safety practices in place. Skin protection (I use nitrile gloves) is essential. Chemical dust and vapor is hazardous and thus must not be inhaled. Respirators or vented chemical hoods may be required for some mixing processes. Safety glasses may also be required.

Pyrogallol (1,2,3-Trihydroxybenzene), Hydroquinone(1,4-dihydroxybenzene) and Pyrocatechol (1,2-dihydroxybenzene) are very closely related benzene ring developing reagents. They are all toxic. In low (or no) sulfite solutions, they are all capable of staining the image and proportionally tanning the emulsion gelatin.

All of these reagents are used in both film and paper developing formulations. A very familiar formulation is Kodak Dektol (Metol/Hydroquinone).

I (and others) have been testing Donald Miller's PPPD (Pyrogallol, Pyrocatechol, Phenidone Developer) paper developing formulation.

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43 gm Sodium Sulfite
.3 gm Phenidone
10 gm Pyrocatechol
5 gm Pyrogallol
50 gm Sodium Carbonate
3.5 gm Potassium Bromide
Water to make 1 liter

Dilute 1-1 to make 2 liter of use solution

The phenidone should be dissolved in alcohol just as in the Pyrocat formula
As in all cases where exposure to Pyrogallol is involved, eye protection, nitrile gloves, and respirator should be worn. (Just as in any pyro formulation).

I am looking for alternatives to Amidol for developing Azo contact prints. Search APUG for PPPD and Amidol.

 

[Tom Stanworth]

Why are you looking for alternatives to amidol; Different look?

 

[Francesco]

Convenience (I do not need to have powdered chems around the house and no longer need to be mixing powdered chems every time I print) and look. Definitely the look!

 

[Tom Hoskinson]

Convenience (I do not need to have powdered chems around the house and no longer need to be mixing powdered chems every time I print) and look. Definitely the look!

Tom, my reasons are the same as Francesco's.

I have componded all the components of PPPD as long shelf life stock concentrates.

I have also succeeded in compounding a concentrated Amidol stock solution (I made a new batch Friday). I dissolved 24 grams of Amidol in 1 liter of hot (220 F) Propylene Glycol. This was done under a vented chemical hood with a hotplate/magnetic stirring bar combination.

 

[Silverpixels5]

I used Don's PPPD developer this last week with very good results. It was a bit too contrasty for my Azo negatives, but printed (enlarged from 6x6) with excellent results on some 10+ yr old Oriental New Seagul Select VCFB paper that I have. I have a negative of mine that would always blow the highlights out on paper(with Ansco 130 or Neutol WA), and with this developer I was able to get detail back in them, as well as a wonderful depth to the photograph. In order to cut the contrast down for Azo, I'll be leaving the pyro out and just go with straight catechol. I still love Ansco 130 both for its tonality and its VERY long shelf life, but I imagine I'll use the PPPD for final enlarged prints. For final Azo prints I plan on using Michael's Amidol formula. I still havn't tried it yet because I don't have enough prints to run through it in order to make the high price worth it....can't mix it up and only put out 5 prints....

 

[Tom Hoskinson]

I used Don's PPPD developer this last week with very good results. It was a bit too contrasty for my Azo negatives....

That is an interesting result. My experience with PPPD is that it gave me fairly low contrast on the current lot of Grade 2 Azo (compared to MS Amidol and Ansco 130).

I started with no KBr in the working developer. It gave me close to a grade 2, and very warm tones - with the Dmax going a bit red. I then added some 10% KBr (twice as much as Don recommended - I goofed) and the developer activity slowed way down. The image tone shifted to blue/black and the contrast dropped to between Grade 1 and 1.5.

I think contrast and tone control is possible by fine tuning the KBr ratio and by increasing/decreasing the dilution.

 

[Silverpixels5]

There seem to be two differences in our materials. 1) I have the old lot of Azo...before the plant change, and 2) I used Don's formula as written, but with 4 grams of Citric Acid to prolong tray life. With the Seagul I got very nice, slight warm tones...and its a cold tone paper as far as I know. I toned them in selenium 1:3 and they went back cold. The Azo developed to a neutral --> slight cold tone.....its kind of hard to tell. Now for one, my negative may have been bit too contrasty since I usually tend to go slightly over in my development of them. I don't know for sure though b/c I don't own a densitometer. I think next time I use the developer, I will have one tray with all catechol and no pyro, and the other with the formula you experimented with. I'm sure one will give me the print that I like from the negative, and work well as a soft developer. If you have any more trials with this developer or various combinations of it, please post your results. Thanks!

 

[David A. Goldfarb]

Regarding the cost of Michael Smith's amidol formula--what I've taken to doing when I don't have a lot of Azo prints to make is that I run the Azo prints first, then add the appropriate amount of KBr and benzotriazole to the amidol to run enlargements in it, mostly on Cachet/Maco Expo RF, which looks really nice in amidol.

 

[Silverpixels5]

Regarding the cost of Michael Smith's amidol formula--what I've taken to doing when I don't have a lot of Azo prints to make is that I run the Azo prints first, then add the appropriate amount of KBr and benzotriazole to the amidol to run enlargements in it, mostly on Cachet/Maco Expo RF, which looks really nice in amidol.

Thanks for the tip David! Now I can use that Amidol thats been sitting in my closet for the past 6 mos. I have plenty of enlargements that I can do, but only a few contacts that are worth running through Amidol.

 

[Donald Miller]

I have followed the results and Tom and of Ron as well. Ron's results are interesting since I have not used citric acid as a preservative before.

My results are not consistant with what Tom has indicated. But then I do not prepare stock solutions preferring instead to mix the developer from individual chemicals immediately prior to use. It takes a little longer but the results are consistant in my experience.

I have not experience the dmax going red in my use of the developer. I can not explain the difference other then the difference that I previously noted. (stock solution preparation).

Sandy King found the developer depleting very rapidly and that was due to the formula as published on www.unblinkingeye.com being inaccurate. (No sulfite noted in that published formula.)

I have found that increasing catechol proportionally to pyrogallol decreases contrast and effective paper speed. By increasing the pyrogallol proportionally to catechol the contrast and paper speed do increase in my tests. I have varied the proportion from 10-5 (catechol to pyrogallol) to 0-15 (catechol to pyrogallol). The remainder of the ingredients remained the same insofar as the ingredients themselves and the amounts used.

Lee Carmichael has used the developer from individual ingredients (no stock solutions) that I provided to him when he was at my home several months ago. He reports that the developer performed as I had indicated.

 

[lee]

Lee Carmichael has used the developer from individual ingredients (no stock solutions) that I provided to him when he was at my home several months ago. He reports that the developer performed as I had indicated.

That is how it worked for me.

lee\c

 

[Tom Hoskinson]

I have not experience the dmax going red in my use of the developer. I can not explain the difference other then the difference that I previously noted. (stock solution preparation).

Don, that is because you put Potassium Bromide (a restrainer) into your working developer and I did not.

As I previously tried to explain (and not very well), the red tones, high contrast and high activity level were the result of my deliberately mixing and using the developer without the Potassium Bromide - I wanted to see what the color and activity level would be without the bromide. When I added Potassium Bromide to that same working developer solution (twice as much bromide as I should have added), the red color disappeared,the developer activity slowed, and the contrast dropped. The resulting Azo prints were quite nice.

 

[Donald Miller]

Tom,
Thanks for clarifying this for me. I didn't understand that the prints with KBR added were acceptable. I wonder if increasing the pyrogallol proportion would bring the contrast to acceptable levels for you. Please let me know if this works for you if you decide to try it.

Don, that is because you put Potassium Bromide (a restrainer) into your working developer and I did not.

As I previously tried to explain (and not very well), the red tones, high contrast and high activity level were the result of my deliberately mixing and using the developer without the Potassium Bromide - I wanted to see what the color and activity level would be without the bromide. When I added Potassium Bromide to that same working developer solution (twice as much bromide as I should have added), the red color disappeared,the developer activity slowed, and the contrast dropped. The resulting Azo prints were quite nice.

 

[Tom Hoskinson]

Don, the first thing I will try is putting in your recommended amount of potassium bromide (3.5 gm Potassium Bromide for 2 liters of working developer).

IMO, the potential ability to raise and lower contrast and change the image tone by adjusting the amount of potassium bromide in the working developer is a good thing!

And as you have mentioned, adjusting the amount of Pyrogallol and/or Pyrocatechol, thus changing the Pyrogallol/Pyrocatechol ratio, are also potential "knobs" for adjusting contrast and tone.

Dilution is another potential knob.

Increasing the amount of water in the working solution should decrease the contrast and change the image tone (colder, I would think).

Decreasing the amount of water in the working solution should raise the contrast and change the image tone (warmer, I would think).