Pyrocat-HD Sudden Death!

A

Alan9940

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I thought my brethren here might find some interest in the following thread that I just posed on the LFPF:

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I know this has been discussed a bit in other threads, but thought I'd pass on a warning that...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. I mix it myself and have done so for more than 10 years. Before that I bought it from PF and had a batch of that go bad in about the same timeframe. No warning. When I mixed A and B together, it turned the appropriate color. I know some of you have had it go bad and others have it last for years. I'm really starting to not trust it due to this Xtol-like sudden death. If I keep using it, I'm going to mix a small batch in distilled water and toss every 6 months or so.

Anyway, just thought I'd pass this along...
**

I know Ian G doesn't seem to have this problem with Pyrocat-HD, but it's the second and, maybe, third time that it has happened to me. FWIW
 
Back in the 60’s when we were looking for maximum tonal range we mixed pyro from the raw chemicals, it was a lovely developer as long as you didn’t mind brown fingernails and a rather short shelf life.
I have never used Pyrocat but guess that it does have a limited shelf life.
 
Mine Pyrocat HD Part A in water lasts at least 3 years, in Glycol I have some that's ( yrars lod. The sudden daeth happens when the Sodium Mrtabisulphite has completely broken down to Sulphite and no longer protects the Pyrocatechin which then oxidises very quickly.

If possible don't use Sodium Bisulphite it gives off less SO2 than Metabisulphite and subsequently less protection.

Ian
 
:eek: oh, no, that fills me with confidence as i head into the darkroom after a great weekend of exposing 5x4 film !!

Alan - is this related to the PF dry-mix Pyro or to home-made mixtures?

I believe Ian "rolls his own" Pyro, whereas many others have to rely of the PF powders.

Mike
 
You could always make life simple and use dilute ID11. This controls the highlights just as well as Pyrocat, aiding darkroom printing, and you won't see any difference in the final print. Dilute Perceptol gives the same benefits.

Alan
 
ID-11 was our usual developer, mostly deep tank but occasionally diluted, but never found it could compete with pyro if you wanted detail in the blacks and very white highlights.
 
Praxinoscope said:
ID-11 was our usual developer, mostly deep tank but occasionally diluted, but never found it could compete with pyro if you wanted detail in the blacks and very white highlights.
Click to expand...

Hi; we may be talking about different things here. I was talking about ID11 at a dilution of 1:2 or 1:3. Your deep tank ID11 was stock solution, I imagine. And I was talking about Pyrocat HD, which you say you have never used...

Shadow detail is a product of exposure, and how well the film developer can deliver film speed. Diluted ID11 and Pyrocat HD have no difficulty in delivering box speed, and in direct comparison tests that I did, both delivered shadow detail in equal measure. And so did Perceptol at 1:3. Rodinal, on the other hand, when used at various dilutions, consistently showed a loss of film speed, and slight lack of shadow detail.

Highlight detail is a product of how well you can get the developer to restrain the highlight densities of the film. Pyrocat HD is well known for staining the negative, in proportion to the amount of activity. So the highlights get stained most, and this stain resists further highlight development. This results in negatives exposed in high-contrast lighting printing easily in the darkroom. But you get exactly the same control of the highlights with ID11 at 1:2 or 1:3, and with Perceptol at 1:3. In a direct comparison test I couldn't see any difference.

But there is something else. Pyrocat HD, well diluted ID11 and well diluted Perceptol all do a great job of delivering full mid-tone densities, whilst restraining highlights. there is no depression of the mid-tones. So you get nice bright prints. Not so with Rodinal, which I found depressed the mid-tones and resulted in a duller print. And Xtol, I found, was even worse.

Alan
 
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We did occasionally use ID-11 diluted at 1:3, but still found a pyro-soda gave us what we wanted in some circumstances.
I agree that diluted an MQ Borax developer such as ID-11 can under many circumstances produce an extended tonal range longer than undiluted but I am referring to just the occasional times when we resorted to using alternatives such as pyro to obtain the end result we wanted.
50 years on I still generally use ID-11, but do once in a blue moon get the chemical scales out and make up some pyro soda two part to get that particular end result.
 
I've not heard of pyro soda. In what way does it differ from Sandy King's Pyrocat developers?

Alan
 
Alan Clark said:
Hi; we may be talking about different things here. I was talking about ID11 at a dilution of 1:2 or 1:3. Your deep tank ID11 was stock solution, I imagine. And I was talking about Pyrocat HD, which you say you have never used...
Click to expand...

When ID-11/D76 is used replenished it's no longer fresh stock solution and the results are quite different, it behaves more like fresh stock diluted 1+2 except slightly shorter dev times, finer grain.

Having used Pyrocat HD now for maybe 15 years it's definitely better than ID-11/D76 in terms of grain, sharpness, tonality, and handles both shadow and highlight detail with ease.

Ian
 
Ian Grant said:
When ID-11/D76 is used replenished it's no longer fresh stock solution and the results are quite different, it behaves more like fresh stock diluted 1+2 except slightly shorter dev times, finer grain.

Having used Pyrocat HD now for maybe 15 years it's definitely better than ID-11/D76 in terms of grain, sharpness, tonality, and handles both shadow and highlight detail with ease.

Ian
Click to expand...

I have to disagree Ian, based on tests I did which were direct comparisons, using 35mm film which shows up differences with bigger enlargements. With FP4+, Pyrocat HD 1+1+100 and Perceptol 1:3 were equal in terms of grain, sharpness, highlight and shadow detail and overall tonality. Pyrocat HD at 2+2+100 is granier. As grainy as Rodinal. But I know you think Rodinal isn't very grainy Ian...
I have used Pyrocat HD a lot. I really liked it. But in my opinion, after testing it against other developers, I am happy to use ID11 and Perceptol, knowing I'm getting similar results from developers that are much easier to obtain.
I don't expect anyone to believe me. But if in doubt, just run a simple test. In hazy sunshine identically expose three sheets of 5x4 FP4. Develop one in Pyrocat HD, one in Perceptol 1+2 or 1+3, and one in ID11, 1+2. Make prints and see if you can see any difference.

Alan
 
I’m not sure of the formulae for ‘Pyrocat’ so can’t comment on it but below is the formulae fo pyro-soda developer or if you prefer ID-1, I think it is very similar to thedev’ that Ansell Adamsused,

Stock solution A

Potassium metabisulphite. 25g.
Pyrogallic Acid. 100g.
Water. 1000 c.c. (Make sure all ‘pot meta’ is dissolved before adding Pyro)

Stock solution B

Sodium carbonate, anhyd. 37.5g.
Sodium sulphite, anhyd. 50g.
Potassium bromide. 1.2g.
Water. 1000 c.c.

To use in dish. 1 part A. 10 parts B. 9 parts water
To use in tank. 1 part A. 5 parts B. 20 parts water

Dev times in tank by experiment but try about 9 mins for HP-5 as a starting point
 
I should have added that pyro devs oxidise rapidly when exposed to air, but they also degrade when exposed to light so preferably keep in opaque bottles or in the dark.
Pyrogallic acid has also got a bit difficult to find and is a bit pricey nowadays, 100g is about £30.
 
mpirie said:
:eek: oh, no, that fills me with confidence as i head into the darkroom after a great weekend of exposing 5x4 film !!

Alan - is this related to the PF dry-mix Pyro or to home-made mixtures?

I believe Ian "rolls his own" Pyro, whereas many others have to rely of the PF powders.

Mike
Click to expand...

Mike, I have "rolled my own" for many years. On another forum, I think Ian G may have hit the proverbial nail in that my Metabisulphite may not be fresh enough.
 
Alan Clark said:
...................., knowing I'm getting similar results from developers that are much easier to obtain .......
Alan
Click to expand...

Pyrocat HD is readily avaiable from Wet Plate Supplies - I checked t'other day :). Mine, mixed in glycol, is still going strong aged 2 years plus and stored in amber bottles in the dark at a constant'ish temperature of around 68 degrees - as is my Xtol-R aged 2½ years. :) Just saying ......
 
@Alan Clark,

Over the years, I've used my film/developer combinations, but I've never found anything that matches Pyrocat-HD's ability to produce strong edge effects when using a minimal agitation technique. If you look at the emulsion side of my LF negs with light glancing off, they have an etched appearance. I've looked at a LOT of negs developed with other developers, but have seen this only with Pyrocat-HD and when using minimal, EMA, stand style development.
 
Praxinoscope said:
I’m not sure of the formulae for ‘Pyrocat’ so can’t comment on it but below is the formulae fo pyro-soda developer or if you prefer ID-1, I think it is very similar to thedev’ that Ansell Adamsused,

Stock solution A

Potassium metabisulphite. 25g.
Pyrogallic Acid. 100g.
Water. 1000 c.c. (Make sure all ‘pot meta’ is dissolved before adding Pyro)

Stock solution B

Sodium carbonate, anhyd. 37.5g.
Sodium sulphite, anhyd. 50g.
Potassium bromide. 1.2g.
Water. 1000 c.c.

To use in dish. 1 part A. 10 parts B. 9 parts water
To use in tank. 1 part A. 5 parts B. 20 parts water

Dev times in tank by experiment but try about 9 mins for HP-5 as a starting point
Click to expand...

Thanks for taking the trouble to post this. I am no chemist but am sure Ian G. will comment..
Welcome to the forum, by the way. I had a nice holiday in Aberaeron once!

Alan
 
Alan9940 said:
@Alan Clark,

Over the years, I've used my film/developer combinations, but I've never found anything that matches Pyrocat-HD's ability to produce strong edge effects when using a minimal agitation technique. If you look at the emulsion side of my LF negs with light glancing off, they have an etched appearance. I've looked at a LOT of negs developed with other developers, but have seen this only with Pyrocat-HD and when using minimal, EMA, stand style development.
Click to expand...
Alan, I do understand what you are saying. And Pyrocat obviously delivers the results that you want. I too have used it with minimal agitation to increase acutance. But I have something that I call the "dead bracken" test. I do most of my photography on the North York Moors where there is a lot of dead bracken in late Autumn and Winter. With too much edge sharpness, eg. too much USM in photoshop, this is rendered on the print in a way that I don't care for at all. So when I used to use Pyrocat HD I used normal agitation and found that my 5x4 negatives were plenty sharp enough for my personal taste.

Alan
 
Alan Clark said:
I have to disagree Ian, based on tests I did which were direct comparisons, using 35mm film which shows up differences with bigger enlargements. With FP4+, Pyrocat HD 1+1+100 and Perceptol 1:3 were equal in terms of grain, sharpness, highlight and shadow detail and overall tonality. Pyrocat HD at 2+2+100 is granier. As grainy as Rodinal. But I know you think Rodinal isn't very grainy Ian...
I have used Pyrocat HD a lot. I really liked it. But in my opinion, after testing it against other developers, I am happy to use ID11 and Perceptol, knowing I'm getting similar results from developers that are much easier to obtain.
I don't expect anyone to believe me. But if in doubt, just run a simple test. In hazy sunshine identically expose three sheets of 5x4 FP4. Develop one in Pyrocat HD, one in Perceptol 1+2 or 1+3, and one in ID11, 1+2. Make prints and see if you can see any difference.

Alan
Click to expand...

Alan, you'll find I say Rodinal isn't grainy with films like Agfa APX100 (not the re-branded AgfaPhoto Apx100), Tmax 100, Delta 100, in fact with these films grain is very fine. In fact ID-11/D76 gives pooer results with Tmax 100 which was one reason for Kodak introducing Xtol which is one of the best commercial developers on the market at the moment. I wouldn't advocate using Rodinal with FP4 and HP5.

I have a friend who used Perceptol 1+2 with Pan F and FP4 and always had great results but there are disadvantages a speed drop compared to Pyrocat HD. or ID-11. I have tested and used Perceptol but it's not an economic developer, replenished Xtol is far better in this respect and is self replenishing. I've been shooting LF hand held so any speed loss is an issue, and depending on contrast I can usually get box speed from HP5.

In hazy sunlight I wouldn't expect much difference between Perceptol and Pyrocat HD or for that matter Xtol, except a speed loss with the Perceptol. However I find Pyrocat HD better at coping with extremes, there's also the matter of fine resolution and micro contrasts something that is better with Rodinal and Pyrocat HD compared to Perceptol and ID-11/D76 due to the solvency affects of the Sulphite in the developers - this improves when replenished or used dilute.

I did extensive testing with 35mm AP100, Tmax 100 and FP4 with various developers some years ago, 35mm film because any differences in grain, resolution etc would be more apparent, the surprise was AP100 @100EI and Tmax100 @ 50EI gave very similar results. Xtol came out a year or two later and gave comparable results I used it mainly with Tmax400.

Ian
 
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