New Pyrocat-M experiences?

Tom Hoskinson · Aug 1, 2006

The differences between Pyrocat-HD, Pyrocat-P and Pyrocat-MC are very small.

I have a concentrated liter of each type mixed in Glycol. I am currently using the Pyrocat-MC because it gives slighty less general stain when long development times are used.

sanking · Aug 1, 2006

KEK said:
Sorry to cut in here also but i've been reading alot of the threads on the pyrocats and i'm a little confused. I just received pyrocat mc in glycol from PF and bought it for a shorter development time and continuos aggitation of sheet film. Did I buy the right pyrocat or are the differences so small between them it doesn't matter.

Kevin

I hope to address previous questions and comments by Evan and Lee, as well as this one.

The differences between all high acutance developers are really very small, and among the Pyrocats the differences are even smaller. However, there are specific reasons why one of the Pyrocats might be favored for a given situation. For optimzing development, taking into consideration the degree of enlargment anticipated, and the expected adjacency effects that would be expected from the type of agitation, here is what I would recommend.

With continuous agitation (rotary processing in Jobo or tubes, for example), Pyrocat-HD for 35mm, either Pyrocat-HD or Pyrocat-MC for medium format films, and Pyrocat-MC for sheet film.

For processing of 35mm and medium format negatives in tanks, with normal agitation (agitation once every minute), Pyrocat-MC. For processing same film in tanks with minimal agitation (agitation every 2-3 minutes), Pyrocat-HD.

For sheet film with normal shuffle processing, either Pyrocat-MC or Pyrocat-HD.

For sheet film with minimal agitation procedures, Pyrocat-HD.

For processing ULF film for alternative printing or AZO 2 with rotary agitation, Pyrocat-MC, because of the low B+F with extended develoment, especially Actinic filtration.

Do not feel constrained by any of this. Pyrocat-HD and Pyrocat-MC are both good general purpose developers and will give excellent results with most films, formats and any types of agitation. And the differences are subtle and nuanced rather than striking.

Sandy

eclarke · Aug 1, 2006

Thanks Sandy, Tom, Lee,
I am using only sheet film and will mix the MC tonight. I am not a densitometerist (??)
but will post my impressions..Evan Clarke

fhovie · Aug 1, 2006

Sandy! Thank you for making these wonderful options available to all of us. I want you to know you are appreciated - along with Pat and Ryuji - and others that make the art of photography a richer and more rewarding expression. Thank You

sanking · Aug 1, 2006

fhovie said:
Sandy! Thank you for making these wonderful options available to all of us. I want you to know you are appreciated - along with Pat and Ryuji - and others that make the art of photography a richer and more rewarding expression. Thank You

Thank you Frank. And I am very pleased to see so many people interested in honing their skills with traditional photographic processes.

Just one more note, and I hope it is not confusing. Because all of my original work with Pyrocat was with water based solution I used sodium metabsulfite as a preservate in stock solution A. When mixed in water the metabisulfite forms sulfite, which adds synergism to the developer and prevents oxidation. It turns out that ascorbic plays an almost exact role, at about 1/3 the amount of sodium metabisulfite, as Pat Gainer noticed in an earlier mesage in this thread.

'No metabisulfite or sulfite. I tried this to in order make all active ingredients soluble in glycol, and it works without sulfite. The same ploy works with the phenidone version, but there is no need for TEA to free the phenidone base. In other words, Pyrocat HD with about 1/3 as much ascorbic acid as usually used of metabisulfite, dissolves readily in glycol at a very moderate temperature and works, IMHO, like Pyrocat HD with the metabisulfite. Go figure!"

In other words, when mixing either Pyrocat-M, Pyrocat-HD or Pyrocat-P in glycol one can substitute ascorbic for sodium metabisulfite at the ratio of about 1:3, and results on the negative will be virtually identical. The advantage of using ascorbic is that it dissolves easily in glycol, whereas sodium metabisulfite must first be dissolved in hot water, then added to the glcyol solution.

However, if you mix Stock A in water the sodium metabisulfite is absolutley necessary as a preservative.

Sandy

Ryuji · Aug 1, 2006

sanking said:
However, if you mix Stock A in water the sodium metabisulfite is absolutley necessary as a preservative.

What if you omit ascorbate and sulfite from your glycol stock?

The preservative actions of sulfites and aerial oxidation of ascorbate are pretty different; they may work alike in your staining developers because you can't use much sulfites anyway, but I wouldn't generalize this relation to other cases.

There are some patents and other documents where ascorbate was used to replace sulfite as a preservative. One example was a color developer (again, only small amount of sulfite can be used). I don't know how well they worked.

Other examples include most of my ascorbate-Dimezone developers, in which higher concentration of sulfite clearly improves the keeping property.

sanking · Aug 1, 2006

Ryuji said:
What if you omit ascorbate and sulfite from your glycol stock?

The preservative actions of sulfites and aerial oxidation of ascorbate are pretty different; they may work alike in your staining developers because you can't use much sulfites anyway, but I wouldn't generalize this relation to other cases.

There are some patents and other documents where ascorbate was used to replace sulfite as a preservative. One example was a color developer (again, only small amount of sulfite can be used). I don't know how well they worked.

Other examples include most of my ascorbate-Dimezone developers, in which higher concentration of sulfite clearly improves the keeping property.

Omitting both ascorbic and sulfite from the glycol stock would not, so far as I can understand, have any negative impact on the keeping qualities of the stock, which would then be just pyrocatechin + a secondary reducer in glycol. However, either ascorbic or sulfite is necessary in the working solution. They add synergism, but more importantly, keep general stain to a minimum.

I certainly would not suggest generalize this relation to other developers. As you suggest, the amount of either sulfite or ascorbic that can be used in a pyrocatechin developer is very low, much lower for example than with pyrogallol. For example, increasing the amount of either sulfite or ascorbic in the current Pyrocat formulas by more than about 3X completely eliminates the stain.

In your ascorbate-Dimezone developers, does increasing the amount of sulfite increase synergism, or developer activity?

Sandy

sanking · Aug 1, 2006

sanking said:
In other words, when mixing either Pyrocat-M, Pyrocat-HD or Pyrocat-P in glycol one can substitute ascorbic for sodium metabisulfite at the ratio of about 1:3, and results on the negative will be virtually identical. The advantage of using ascorbic is that it dissolves easily in glycol, whereas sodium metabisulfite must first be dissolved in hot water, then added to the glcyol solution.

Sandy

Some might be interested in looking at families of curves for Pyrocat-HD, Pyrocat-M, and Pyrocat-MC. As you can see, from the perspective of sensitometry there is very little to separate them. The small differences observed are probably due more to different batches of Ilford FP4+ and slight inaccuracies in the method of testing than to absolute diffeerences between the developers. Other tests with the same film (emulsion batch) for one time of development (ten minutes) carried out at the same time have given virtually identical results.

BTW, these are real files of FP4+ developed in these three versions of Pyrocat. If you use rotary processing you could use the data for your own developing, bearing in mind that a SBR of 7 would be what you would shoot for in scenes of normal contrast. The numbers you see at the top of each curve, reading from left to right, are 1) time of development, 2) EFS, 3) CI, and 4) SBR. The ES is set at log 1.30, a value I consider about correct for VC silver papers.

The analysis was by Blue mode readings. The sensitometry does not tell us anything, of course, about appearance of grain and apparent sharpness. Other tests, including real life work, would be needed for that.

Sandy

haryanto · Aug 1, 2006

Thanks a lot to Sandy and others, for his generous to share his knowledge about Pyrocat HD,
I've used phd for 3 months, and now I give a try with Pyrocat MC but with distilled water + 1gr Potassium bromide, my problem is there's a lot of my negative has streaking (small area that has a lot of density) when i use semistand dev, 5 minutes pre wash, 1 minutes agitation, and every 3 minutes then,
does anybody know, why?

in the pyrocathd recipe, there's potassium bromide 2gr /1lt, and in pyrocat MC no potassium bromide, is it correct?

thanks before

gainer · Aug 1, 2006

Yes. No bromide, no sulfite or bisulfite.

haryanto · Aug 1, 2006

gainer said:
Yes. No bromide, no sulfite or bisulfite.

Thanks Pat Gainer, for quick reply,
what would it be if there's 2 gr/lt Pot Bromide?
what different betwen solving Pyrocat MC with distilled water and if it use Prop Glycol?

thanks before

sanking · Aug 1, 2006

haryanto said:
Thanks a lot to Sandy and others, for his generous to share his knowledge about Pyrocat HD,
I've used phd for 3 months, and now I give a try with Pyrocat MC but with distilled water + 1gr Potassium bromide, my problem is there's a lot of my negative has streaking (small area that has a lot of density) when i use semistand dev, 5 minutes pre wash, 1 minutes agitation, and every 3 minutes then,
does anybody know, why?

in the pyrocathd recipe, there's potassium bromide 2gr /1lt, and in pyrocat MC no potassium bromide, is it correct?

thanks before

OK, first, you don't need any potassium bromide in Pyrocat-MC (or in Pyrocat-M or Pyrocat-P) as you do in Pyrocat-HD. I believe this is because the pH of a working solution of Pyrocat-MC (and Pyrocat-P) is just about optimal, whereas with Pyrocat-HD, so you need a bit of restrainer to avoid reduction of non-exposed silver grains, which would cause a slight excess of B+F.

As for the streaks, could you describe how you are developing the film? In tubes, tray, on reels? And include any details you consider important.

BTW, I call the method of agitation you described above, i.e. agitation at intervals of every 2-3 minutes, minimal agitation, not stand agitation.

Sandy

haryanto · Aug 1, 2006

sanking said:
OK, first, you don't need any potassium bromide in Pyrocat-MC as you do in Pyrocat-HD. I believe this is because the pH of a working solution Pyrocat-MC (and Pyrocat-P) is about optimal, whereas it is just slightly too high with Pyrocat-HD.

As for the streaks, could you describe how you are developing the film? In tubes, tray, on reels? And include any details you consider important.

BTW, I call the method of agitation you described above, i.e. agitation at intervals of every 2-3 minutes, minimal agitation, not stand agitation.

Sandy

I've used tube for develop my FP4 and TMX100 4x5, agitations by rolling the tube 10 seconds in every 3 minutes

(you're right about excess BF with Pyrocat MC with bromide)

thanks

sanking · Aug 1, 2006

haryanto said:
I've used tube for develop, agitasi by rolling the tube 10 seconds in every 3 minutes

(you're right about excess BF with Pyrocat MC with bromide)

thanks

Did you develop with the tubes in horizontal orientation?

If so, it is almost certain that some areas of the film would have been developer starved during the period of rest.

For minimal agitation in tubes, you need to stand them in vertical orientation, and fill them with developer to the very top. That way, developer will be in contact with all of the film while it rests between agitation.

Hope this is clear.

Sandy

phfitz · Aug 1, 2006

Hi there,

Sandy:
"Further notes. My original work with the Pyrocat formula was carried out with phenidone. However, once the formula with phenidone was published I kept getting reports from people about substituting metol for phenidone at the same amount. The really confused me, because normally we expect about a 10-15-:1 ration of metol to phenidone to get the same level of activity. But results are results, so in March when I decided to test a couple of Pyrocat variants, the -P and -M variants, I decided to carefully test the optimum amount of metol in the formula, and what I found was that it was indeed about the same amount per weight as phenidone. I don't know how to explain this, but this fact is the primary key to the great qualities of Pyrocat-M and Pyrocat-MC."

So Pyrocat and Metol are an actual 'superadditive' pair, they have both been in use for 50 years and this is just being found out. There is hope for the future of film.

Pyrocat MC uses so little metol that people with a metol allergy should be able to try it out without fear of a rash. This can only be a good thing.

Thanks for the work and posting this thread.

haryanto · Aug 1, 2006

I've stand my tube vertikal, this is the photos, I attached here

sanking said:
Did you develop with the tubes in horizontal orientation?

If so, it is almost certain that some areas of the film would have been developer starved during the period of rest.

For minimal agitation in tubes, you need to stand them in vertical orientation, and fill them with developer to the very top. That way, developer will be in contact with all of the film while it rests between agitation.

Hope this is clear.

Sandy

sanking · Aug 1, 2006

haryanto said:
I've stand my tube vertikal, this is the photos, I attached here

Thanks for the images. Those fogged areas look like light leaks to me, not streaking from development.

The only othe explanation I could think of is that the film has been inserted into the tube with the emulsion facing the inside wall of the tube, and small areas of the film are not receiving any developer.

In any event, I am very confident that this event is not a developer problem, but some type of mechanical issue.

Sandy

Ryuji · Aug 2, 2006

sanking said:
However, either ascorbic or sulfite is necessary in the working solution. They add synergism, but more importantly, keep general stain to a minimum.

Just to clarify... Superadditivity of MQ and PQ type developers, and catechol/pyrogallol versions thereof, is said to appear when sulfite is present. But this is because, if sulfite is not added, hydroquinone or catechol can develop image faster and they may not need much help from Metol or Phenidone, especially when the pH is high enough. This does not mean sulfite is required for development. Someone on this forum sometimes states something that give me the impression of his misunderstanding.

This does not hold in ascorbate developers. Regardless of sulfite content, development by ascorbate itself is very slow, although ascorbate is a more powerful reducing agent. So both in theory and practice, superadditivity is not dependent on sulfite in ascorbate developers.

Developer activity (development time) and effective film speed may be modulated by the presence of sulfite. More importantly, tonal character and granularity are influenced by the amount of sulfite. In terms of practicality and reliability (from the user's view), sulfite is also an important developer constituent.

haryanto · Aug 2, 2006

thanks a lot Sandy for quick reply, I will search again for light leaks in my darkroom, so far as I know there's no leaks, but I'll check it again,

thanks again

sanking · Aug 2, 2006

haryanto said:
thanks a lot Sandy for quick reply, I will search again for light leaks in my darkroom, so far as I know there's no leaks, but I'll check it again,

thanks again

But the fogging is very specific, not what we would expect from darkroom leaks, which would cause general fogging.

Sandy

haryanto · Aug 2, 2006

yupe, the leaks come from one of my tubes, I paint it black, but some paint seems tear off from the tube,

I've used 3 tubes for develop I thought the fogged come from developer because there's randomly fogged not in all my negative

thanks

ongarine · Aug 21, 2006

My aim to try Pyrocat-M evolved in a batch of Pyrocat MC dissolved in water (no TEA in my darkroom at this moment) and used at 90% in the first week of its life to prevent the rapid damage of the Vitamin C solution in water.
I dveloped the following films:
Classic 400 Iso 120 Pyrocat MC 1:1:100 10,30 minutes 21 C
The negatives print better on graded paper n.3 Fortezo, sometimes shadows are too thin.
So I remembered that most of Classic 200 and 400 Iso were developed with a 2:2:100 diluition.
I tried the following combination:
Classic 400 Iso 120 Pyrocat MC 2:2:100 10,30 minutes 21 C
Classic 200 Iso 120 Pyrocat MC 2:2:100 8,30 minutes 21 C
They print very well on Fortezo grade 2 with very good shadows and higlights.
I have also the bunch of J&C Pro 100 8x10 to develope.
All the negatives were exposed in very gray day, no sun, and subjects are old castles and fortified walls.
I souped the four sheets for the test (two subiects with two different exposition) in:
J&C Pro 100 Iso 8x10 Pyrocat MC 1:1:100 13 minutes 21 C
Not so good to print on grade 3 Fortezo, too thin, but the negatives are really difficult, so I tried:
J&C Pro 100 Iso 8x10 Pyrocat MC 2:2:100 10,30 minutes 21 C
The result was really better and this morning I printed most of them on Efke Emaks grade 3 with a great satisfaction.
My final note is: is really Pyrocat MC different from HD?
The results show a really slightly differences in contrast MC more than HD, but the rest seems the same.
MC is very close if not the same that Pyrocat HD with a small amount of Vitamin C in it.
My tests are not made with specific instruments, only my eyes and a small experience.

gainer · Aug 21, 2006

Perhaps I can throw a little different light on your experiments. It has been known for some time that metol and ascorbic acid are synergistic without the presence of sulfite. The autocatalytic effect of developed silver on the development of silver has also been known, or at least theorized. It was desired to have a substitute for sulfite that could be dissolved in organic solvents as for example TEA or a glycol.

When water is used as he solvent for the stock solution, one should be able to make it with metol, p-aminophenol, phenidone, catechol and sodium sulfite, and without ascorbic acid. The stock will not last as long as would one dissolved in the organic solvent.

It appears from Sandy King's tests involving measurements of characteristic curves that there are differences among the varieties of Pyrocat, some of which might not be noticable by most of us.

Anyway, when you get some TEA and glycol, I'm sure you will want to try the organic stock solutions.

sanking · Aug 22, 2006

gainer said:
It appears from Sandy King's tests involving measurements of characteristic curves that there are differences among the varieties of Pyrocat, some of which might not be noticable by most of us.

Anyway, when you get some TEA and glycol, I'm sure you will want to try the organic stock solutions.

Mixing Pyrocat in glycol, whether -HD, -MC or -P, is highly recommened if you are not likely to use up the stock solution within about six months.

From the perspective of sensitometry there is very little difference between the three Pyrocats if measuring with Visual or Blue mode. And that is not by accident since I adjusted the amount of metol and p-aminophenol to give the same energy level as with Pyrocat-HD. However, for UV mode there is an advantage to Pyrocat-MC in that B+F or general stain is somewhat less with long develoment times than with Pyrocat-HD. Also, if you look at the grain structure through a microscope you will see a distinct difference between the three developers, which could matter for persons enlarging 35mm and roll film.

Finally, although my original testing indicated the contrary, a lot of additional testing recently has convinced me that Pyrocat-HD gives the highest EFS with most emulsions (which is just a tad more than D76 1:1 but less than Xtol by about 1/4 of a stop), followed very closely by Pyrocat-MC, with Pyrocat-P showing a loss of about 1/4 stop relative to Pyrocat-HD. However, as I have mentioned before in this thread, small variations i results are to be expected with formulas that we mix ourselves since we often wind up using chemicals from a variety of sources.

Sandy King

Ryuji · Aug 22, 2006

gainer said:
It was desired to have a substitute for sulfite that could be dissolved in organic solvents as for example TEA or a glycol.

Such substitute has been known and used in commercial products for decades.

New Pyrocat-M experiences?

Tom Hoskinson

sanking

eclarke

fhovie

sanking

Ryuji

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sanking

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haryanto

gainer

haryanto

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haryanto

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phfitz

haryanto

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Ryuji

haryanto

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haryanto

ongarine

gainer

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Ryuji

New Pyrocat-M experiences?

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