Divided Pyrocat from the Formulary

[swmcl]

Hi,

I have read the suggested article from Sandy King at http://www.pyrocat-hd.com/html/mixing.html and am not sure how this relates to the PyroCat-HD in glycol product at the Formulary (01-5091 or 01-5093). Is it as simple as Solution A and Solution B at 1:10 ?? Along with the PhotoFlo of course.

In the same article I also am confused with a reference to TEA ... what is TEA ?? I'm thinking it is the drink that many of the English and her colonies drink at many instances throughout the course of a normal day !!

Cheers,

Steve

[sanking]

Hi,

I have read the suggested article from Sandy King at http://www.pyrocat-hd.com/html/mixing.html and am not sure how this relates to the PyroCat-HD in glycol product at the Formulary (01-5091 or 01-5093). Is it as simple as Solution A and Solution B at 1:10 ?? Along with the PhotoFlo of course.

In the same article I also am confused with a reference to TEA ... what is TEA ?? I'm thinking it is the drink that many of the English and her colonies drink at many instances throughout the course of a normal day !!

Cheers,

Steve

First, TEA is Triethanolamine. It is not used in any of the Pyrocat versions. I did experiment at one time with a one part pyrogallol based developer mixed in TEA but decided to not pursue work with the formula.

Pyrocat comes in two stock solutions that are diluted with water to make a working developer. A typical dilution is one part A + one part B + 100 parts water. Weaker or stronger dilutions may work better with some films.

Divided Pyrocat is pretty much as you surmise, Solution A and Solution B are mixed 1+10 to 1+20. The film is first soaked in working solution A for a few minutes, where it absorbs the reducer, then placed in working solution A (the alkaline accelerator), where development takes place.

Some people mix Stock A of Pyrocat in glycol. Glycol provides an anaerobic environment that prevents the reducer from breaking down.

Sandy

[swmcl]

Thanks Sandy,

With some using a coffee based developer I thought that the Earl Grey might come in handy !! Not.

I'm assuming there is a water rinse at the start ? Then X minutes in Solution A (1:10) with PhotoFlo then Y minutes in Solution B (1:20) then a rinse in water before the stop and then onto the fixer.

I'm using FP4 primarily.

Cheers,

Steve

[sanking]

Thanks Sandy,

With some using a coffee based developer I thought that the Earl Grey might come in handy !! Not.

I'm assuming there is a water rinse at the start ? Then X minutes in Solution A (1:10) with PhotoFlo then Y minutes in Solution B (1:20) then a rinse in water before the stop and then onto the fixer.

I'm using FP4 primarily.

Cheers,

Steve

I tried to develop a sheet of film in chamomile and nothing came out. Should I have used Earl Grey instead?

I recommend a pre-soak for thin emulsion type films to swell the gelatin as much as possible. How much the gelatin can swell is the primary determinant of how much reducer the film can imbibe. With films like FP4 the pre-soak should not be necessary, but neither will it cause any problem.

The strength of the dilution, together with time, determines final contrast. To keep it simple I suggest 1+15 (for both working solutions), and about 5 minutes + 5 minutes at 75º F, for films like FP4, Acros, Tmax-100. Lower contrast films like Tri-X and HP4 need a stronger dilution to reach the same contrast. For example, the same treatment of of FP4 and TMY results in higher contrast in the FP4 negatives.

Sandy

[Kirk Gittings]

Sandy what kind of developing apparatus (tray, drum etc.) and agitation are you talking about for these dilutions and temperatures.

[sanking]

Kirk,

I have used this method of development with sheet film primarily in a drum, rotated on a motor base. The drum for 5X7 film is one of the old Beseler 8X10 drums that will accept two sheets of 5X7 film. Motor base is an old Unicolor unit. The routine is.

1. Mix the working Solution A and B, adding a few drops of PhotoFlo to A. Mix the solution at about 75º F.
2. Pour Solution A into the drum, and rotate on the base for five minutes.
3. Drain Solution A form the drum, allowing about 20-30 seconds.
4. Pour in Solution B and rotate again for five minutes.

The most critical part of the routine is clean draining of Solution A (PhotoFlo helps), and completely and immediately wetting the film, now soaked with reducer, in Solution B. If the film does not drain evenly and/or if it does not come into contact with Solution B almost instantly everywhere, the risk of streaking is possible.

The procedure requires some practice to get right, but for scenes of very high contrast it is as close to a silver bullet as you can get. More like a gold bullet in fact.

Sandy

[richardman]

I used Divided Pyro on a Jobo for two years. Now I am back to Xtol only because there's a 5L bag sitting around. When that's done, I will probably go back to Divided Pyro. 135, 120, 4x5, all come out looking good.

[Kirk Gittings]

Sandy, Thanks. What do you think of this procedure in BTZS tubes? Similar?

[sanking]

Sandy, Thanks. What do you think of this procedure in BTZS tubes? Similar?

Kirk

I have developed a lot of film in BTZS tubes but have not used the tubes for divided development. The only problem I see is what do you use to hold Solution B, since you have already used the fill caps with solution A?

Sandy

[Kirk Gittings]

Thanks. I have three sets of caps.