Advice from Pyro users

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mpirie

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Hi guys, quick question (which will probably have a long answer) but is there an exhaustion concern with Pyro-HD?

Reason for asking is that yesterday, i mixed up 900ml of solution (1+1+100) ready for 3 runs of 300ml for 2 sheets each of FP4 in my Jobo.

First pair of sheets came out as expected, second and third pairs came out almost clear film. On closer inspection, the 2nd and 3rd pairs had VERY faint images, so i'm happy that i didn't mix up the dev and fix :)

All I can think of is that the 2hrs between the first pair and second pair was enough for the Pyro to exhaust (even though it was in a closed bottle). The second solution even had a different colour upon emptying than the first batch.

Anyone else got experience of Pyro exhaustion? I guess the lesson is to make it up literally just before i need it.

Mike
 
Once made up Pyrocat (any form) has a very short life. It starts to change colour after about 15-20 minutes showing it's beginning to oxidise. I wouldn't use it after more than that sort of time, it's so fast to mix up fresh each time.

I will mix enough for 2-3 tanks but I have 2 Jobo 2000 tanks and often have a Paterson tank with 120 films as well, I stagger them 5 or 6 minutes between filling each tank.

Ian
 
Ian, are you mixing your PyroCatHD A + B from Raw chemicals or do you buy it ready mixed
 
I mix all my stock solutions from raw chemicals, the only thing I don't make up myself is fixer, and selenium toner.

One print toner I occasionally use is Ilford IT-8 which gives olive brown tones, it uses a Dichromate rehalogenating bleach followed by a simple Pyrocatechin redeveloper which has about a 5 minute tray life once Parts A+B are mixed. I actually use Pyrocat HD isntead as it lasts significantly longer.

Ian
 
Currently, I am buying the PyroCatHD ready made in 500ml of A+B in Glycol. The batch I am using at the moment was mixed in July 2017 and is stored in brown glass bottles. Do you need a lot of equipment to mix it from the raw state
 
You need accurate scales, I have a beam balance that weighs accurately to +/- 0.01g, and a couple of electronic scales that are +/- 0.1g. Then reasonably accurate graduated measures. Plus a supply of raw chemicals, and decent bottles.

I worked as a photo-chemist (and emulsion manufacturer) for over a decade so it's second nature for me. I've photo-chemicals like Phenidone I bought in 1976 that are still as good as new, Ilfords date code shows it was actually made in 1961. I've bought a lot more since :D

Later when I worked in the Jewellery industry as a Gold refiner and ran an analysis lab (it's very similar chemistry to Photography) I bought the complete specialist Photo-chemical stock from Hogg Lab Supplies when Mike Hogg ceased his father Ninian's niche side line (he sold the complete company a year or so later) I bought the lot for £25 - Mike's suggested price :D

If you think you'll use enough chemistry it's worth making your own from raw chemicals. I've made my own colour chemistry but it's not really worth the effort time-wise.

Ian
 
I suspected that the measuring devices had to be really accurate. Foe ease, I will stick with buying them already mixed. So far, everything is working out despite the fact they 6 months old now
 
Thanks Ian, sounds like my suspicions are correct, that the dev had become exhausted before i was ready to use it.

The only way to confirm this will be to make up a fresh mix just before i need it.

Mike
 
Ian-Barber said:
I suspected that the measuring devices had to be really accurate. Foe ease, I will stick with buying them already mixed. So far, everything is working out despite the fact they 6 months old now
Click to expand...

Made up in water Part A will keep about three years in high density plastic or glass bottles, in Glycol in theory longer.

There was a developer Prescysol which was in fact Pyrocat HD (using Sodium Carbonate in Part B), this had a poor shelf life as it was supplied in low density plastic bottles.

Ian
 
Ian Grant said:
Made up in water Part A will keep about three years in high density plastic or glass bottles, in Glycol in theory longer.
Click to expand...

Ah thats good as I know it was mixed in Glycol. What about the shelf life of Part B ?
 
Part B will last longer than Part A but not indefinitely, so I wouldn't keep more than about 3 years.

Ian
 
I have contemplated selling darkroom chemistry, I looked into the costings and it's feasible. I don't think Pyrocat HD would be that expensive. I have a large stock of 200ml bottle but unfortunately they are similar to those Peter Hogan used for Prescysol and so useless, people want more than 2-3 months shelf life.

Ian
 
There is a fellow photog selling Pyro-HD on the auction website. He sells A and B in 100ml bottles. I've asked him to look at larger quantities. The biggest issue for me buying pre-made from commercial suppliers is that they have to use expensive couriers.
 
Ian-Barber said:
I buy my pre-mixed PyroCatHD from Kevin here at
http://www.wetplatesupplies.com/alternative-processes/film-developers/pyrocat-hd-premixed.html

Ian if you invest in a small digital scale and mix your Pyrocat HD from 'scratch' your $ investment would be
beneficial since the dry chemicals will not 'deteriorate' any where near as fast as kept in tightly closed containers.
I find that my 'archiac' three-beam balance to be well within the needs of accuracy. And.. you are not paying for the shipping, which may often 'equal or perhaps double your costs...


Ken
Click to expand...
 
I've been following this thread with fascination and understanding less than half.
May I ask what unpaletable defects in, say ID11, have led you to dance on so many pins?
 
#1 reason is 'sharper' grain edge but to be honest I don't seem to 'see' much in the way of the 'staining i got with PMK

Ken
 
The staining is there Ken, it's more noticeable with some films than others HP5 and Fortepan 200 seem to have the most apparent stain of the films I've used. If you bleached a scrap negative you'd see it. I use Pyrocat HD sometimes as the re-developer with Ilford IT-8 bleach, it's a Dichromate/Bromide bleach and uses a plain Pyrocatchin re-developer for Olive brown tones (Quite different to Sepia) but the dev doesn't keep well where as Procat does.

Ian
 
So this is only useful for straight darkroom printers? Digital printing offers all kinds of ways to modify edge contrast. You can even control edge sharpness selectively and locally.
What sort of size do you need to print, before these effects are apparent? What do you do if the effect is too much?
And when you say"grain edge" does this mean the individual grains are rendered more sharply or that the transition from a light patch to a dark patch is enhanced, by Mackie lines? I thought this was related to very dilute (but standard) developer, used with very little agitation. I can recall seeing N-shaped graphs illustrating this but I also recall a suggestion that one of the lines doesn't exist and is a purely retinal effect. My apologies, but I can't remember the reference. Might have been a passing comment in the BJP...
I had believed that staining developers were used to control the contrast of tricky subjects, in the days of graded papers.
 
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David M said:
I've been following this thread with fascination and understanding less than half.
May I ask what unpaletable defects in, say ID11, have led you to dance on so many pins?
Click to expand...


I used ID-11 (D76) for many years replenished in deep tanks, that's where it gives it's best results. We switched to Adox Borax MQ (3 of us using the film darkroom) which gives slightly finer grain, better shadow detail and a touch better speed, again replenished. I made it up from raw chemicals.

Later I switched to Xtol (replenished) when it was released, for commercial work, it's the best commercial developer for Tmax films which I was using by then. It's worth looking at Kodak's own comparison chart.

ID-11/D76 doesn't quite give the sharpness or fine grain that you get with Adox Borax MQ, Xtol, or Pyrocat HD. I used to shoot quite a bit of 35mm and always wanted the best results from my films. One advantage of Xtol is it doesn't have a separate replenisher, you just use fresh developer to replenish.

With LF the differences are less noticeable, but I now shoot MF instead of 35mm and again want the best from my films and I'm getting that with Pyrocat HD and negatives that print (and scan) easily..

Ian.
 
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