I started out using the nbPyrocat-HD version, I then went to Pyrocat-MC and really was happy with it, but when I heard about Pyrocat-HDC I thought I'd give it a go and see how it compared. Well, I'm still using the HDC version and like it just as well as the MC version, but I could easily use either the MC or HDC and be happy for life. These Pyrocat formulas are the best thing since sliced bread. Of course for much of what I do Xtol-R does the job just fine.There's a variant of Pyrocat called Pyrocat HDC which could be of interest to those who want a long lasting variant of Pyrocat. It doesn't use metabisulphite+bromide and hence completely avoids water. I believe ascorbic acid which dissolves nicely in warm glycol provides the necessary acidic environment to prevent the oxidation of catechol. Developing time and results are supposed to be very similar to HD.
There's a variant of Pyrocat called Pyrocat HDC which could be of interest to those who want a long lasting variant of Pyrocat. It doesn't use metabisulphite+bromide and hence completely avoids water. I believe ascorbic acid which dissolves nicely in warm glycol provides the necessary acidic environment to prevent the oxidation of catechol. Developing time and results are supposed to be very similar to HD.
YES, Pyrocat-HD can experience sudden death significantly before you expect it and without warning.
I have a 15 month old batch, mixed in glycol, stored in amber glass bottles with a spurt of Protectan after each use, and kept at about 50-55F in the dark.
In "The Book of Pyro" Hutchings says that pyro by itself gives very low film speeds, usually half. Just trying to explain the complete lack of shadows.
Yes I watched a dude in my darkrooms process thousands of Acros 4 x 5 film in Pyrocat . He was no dummy , but at the time he was having this complete shadow low end failure consistently, and to my knowledge never sorted out exactly what happened, I think the experience really turned him off film and process as he has not done any since and at the time he was indeed a real keener.
I never in my whole career witnessed or seen this type of problem and like I said he was no slouch and he called every expert on Pyrocat and suppliers and during this time processed dozens of runs of test film that he specifically shot in my back alley to figure out the problem .. I stayed out of it as this project was his work , his financial commitment on film , chemicals and of course renting my space, but he was having these really unexplainable errors that everyone attributed to operator error .
I believe he was referring to Pyrogallol, although I would assume the info to be applicable to Catechol as well.Was Hutchings referring to Pyrogallol or Pyrocatechine (Catechol) or both?
According to the directions, you have to add a little water to the glycol anyway, so I'm not sure how a few drops more would make a big difference.since I switched from glycol to water based mixes, I have never had any issues with my pyro going belly up. the only reason I came up with is that the water from rinsing my syringe was somehow ruining the A solution. I use 2 syringes, one for each solution so as to not contaminate them...I guess the water cant screw the water solution, so to speak..
since I switched from glycol to water based mixes, I have never had any issues with my pyro going belly up. the only reason I came up with is that the water from rinsing my syringe was somehow ruining the A solution. I use 2 syringes, one for each solution so as to not contaminate them. Most of my sudden death came after major shooting trips. I would come home and develop 10-30 rolls of 120 film in a day. so between each batch I would wash and towel dry the syringe. it would get used again for the next batch and so on. like I said above, when I switched to using distilled water for the A solution, I never had the issue. I guess the water cant screw the water solution, so to speak. B is always mixed with distilled water. the nice thing is I can mix up 300ml and use it on 6 months or less and if not, I can dispose of it and not worry.
Alan, was your experience with sudden death a total loss of shadow detail, or something else?As IanG suggests, I think there is something much more complex going on with those of us who have experienced sudden death.
Alan, was your experience with sudden death a total loss of shadow detail, or something else?
I don’t remember if the catechol was the same color 18 months ago. Nor do I recall the color of my last batch of solution A, which was mixed using the same containers of all chemicals. What colors are others seeing?
These are the results i was having earlier this year. When processing in my 2500 tanks, the first batch would come out perfectly, the second tank-load would fail completely, with only the faintest detail visible.Basically, a total loss of the entire image. I could see just a faint trace of parts of the image.
Alan - If you still have the old batch, it might be worth trying it in trays?
I tossed it and mixed fresh just to verify for myself that one or more of my raw chemicals had not gone off.
It was nice to discover that the "sudden death" was really just me making a mistake.
I figured if Sandy had settled on the HDC then I might as well make the switch and never think about it again.@ParkerSmithPhotoPyrocat-HD is such a nice developer I keep using it. Based on discussion in this thread, though, I may give HDC a try.
Alan, I was about to toss my early 2016 Pyrocat-HD in glycol but decided to run a test roll, thinking that I may have made a dilution error when I experienced "sudden death." My guess was correct. The test roll came out perfectly. I ran part of the same roll through some fresh Pyrocat-HDC in glycol as well. The HDC looked a little denser, which was most likely the result of a slight variation in the B mix concentration. That is, my mix may have ended up stronger than the standard 75% solution of PC from Photo Formulary.
I also ran a test with the old A and the new B which very closely matched the HDC negative, further confirming my belief that my B mix might be a little stronger than standard.
One thing I did before making these tests was to create a dilution workflow checklist so that I marked off and confirmed volumes as I added each solution to the water. Sounds silly, but it's so easy to get working and kind of go on auto-pilot, and clearly I made that mistake last week (ruining four rolls), so this should help.
Good news is, this batch of Photo Formulary Pyrocat-HD in glycol has been in brown bottles with vacuum stoppers for coming up on four years, and seems to be working just fine. It was nice to discover that the "sudden death" was really just me making a mistake. I will post some pics of the negatives after they dry.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?