2 bath Pyro developer

I posted this on LFPF but there may be some that don't visit who are only roll film users.

Most of my photography these days is with my 5x4 but the other day I checked my freezer and found to my delight that I had frozen 40 [120] rolls of APX 100 in 2005. I couldn't remember what I used in the past to process regarding time and temperature etc so I figured I would investigate a 2 bath developer. The first obvious choice was Barry Thornton's 2 bath that so many people really like. I had all the chemistry on hand but then saw a post by "Relayer" here on APUG about a pyro 2 bath he had designed. It has phenidone which I had so I made a small test quantity. My phenidone was obviously not well as the results were less than stellar. I do have plenty of Metol so rejigged the formula to include Metol and adjusted the "B" bath to a concentrated formula for hopefully better consistency.

My stash of APX 100 performed very well returning box speed. I also tried an old roll of TMax 100 that had experied in 2002 and kicked around in my darkroom through 40+ degree summers. Despite all that mistreatment it was only 1/3 of a stop down on box speed. I simply took one reading of the deepest shadow and put that on Z3. The developer controlled the highlights very well allowing me to print on a basic grade 2 filtration. The thing I really liked was being able to get film speed and development times sorted in one film, actually half as I cut the film to do a second run if the development wasn't correct.

The Tmax didn't show any stain where the APX had just a slight hint of stain.

To make 500 ml

Part A

25 gm Sodium Sulphite
2 gm Metol
4 Gm Pyro
3 gm Sodium Metabisulphite


Part B

Sodium Sulphite 120 gms
Sodium Carbonate 80 gms

Water to make 500 ml

Dilute 20 ml / 500ml for use

Can do 2 - 3 film then discard. However as a one shot it will be more consistent


or

Alternate part "B"

8 gms Sodium Carbonate
15 gms Sodium Sulphite

500 ml of water.

will do 5 - 10 films [ pour back into bottle after use]


I found 3 minutes in each bath was all I needed to give easy to print negatives on my diffusion enlarger.

Before mixing this developer be aware of the toxicity of Pyro. Wear gloves and eye protection etc. etc.

I have been splitting Pyro PMK into two developer baths for over 15 years , I found that this is one of the keys to rotary process with a developer like PMK.

Would you mind outlining how you do that Bob? That sounds very interesting.

Really simple, I use Jobo and mix 1000ml for each developer bath.

so I set all the tanks up with solution ie pre wash , wash stop , fix..

then when the tanks are loaded with film lets call it trix I determine a 14 min development .. I mix 2000ml of PMK at the moment I am ready to develop I separate into two tanks. I use distilled water for the developer.


pre wash 2 min
PMK first bath 7 min
PMK second bath 7 min

and water stop fix as normal

I unlike many others here use the exhausted developer to stain as the final bath before washing.

then wash and then wetting agent in distilled water to hang dry.

I tried that 2 bath pyro/phenidone formula but also got inconsistent results and was also doubtful of one of the chemicals, can't remember which now, because it had some grey colouration. It was the first 2 bath I have tried as I had most of the chems but I was unsure about agitation.

This is with 120 film in a steel reel and tank. The first film came out well but suffered from streaking. I followed Diafine instructions for agitation, one every 30sec both baths. I then read Barry Thornton's 2 bath instructions and read up on forums so tried the next with constant agitation Bath A and one inversion during Bath B. This came out better but mid tones seemed lacking. So I then tried constant A and one inversion /min and again was disappointed with the mid tones and still had more streaking on two or three frames and some areas of blotchy development.

Could be a number of factors and I think the steel reel and drum which has a smaller volume may have a bearing. But what is the agitation procedure you follow for this? I look forward to trying your Metol formula.

Thanks

Hi richyd,

In bath A I agitate for the first 30 seconds, then 10 seconds on the minute. Drain the part A back into its bottle then add part B and agitate for 10 seconds at the begining. At the 90 second mark I invert the tank once gently and tip the part B back into the part B bottle when the development time is completed. Rinse with water not an acid stop for about 60 seconds then fix as normal.

My experiment was done with 120 roll film in a single reel stainless steel tank using 400 ml of each solution.

The concentrated part B I calculated is far too over saturated so should be mixed in at least 1 litre of water and the concentrate then diluted 40/500 for use. At that it seems fine. Mixed as a concentrate at 500 ml the chemicals precipitated out over night. If I find the concentrated version is problematic I will use the Alternate part "B"

8 gms Sodium Carbonate
15 gms Sodium Sulphite

500 ml of water.

Hope it works for you and try a film that doesn't matter.... just in case.

Thanks, Steve I'll get some Metol over the weekend and make up a batch for my next film.

chiller said:

I had all the chemistry on hand but then saw a post by "Relayer" here on APUG about a pyro 2 bath he had designed. It has phenidone which I had so I made a small test quantity. My phenidone was obviously not well as the results were less than stellar. I do have plenty of Metol so rejigged the formula to include Metol and adjusted the "B" bath to a concentrated formula for hopefully better consistency.

Click to expand...

Sorry, I was out of home and can't reply. You right - Phenidone can be substituted with ~10x amount of Metol. But note that Metol in solution is acidic, so you need to adjust pH and possible decrease amount of metabisulfite. Also Phenidone give more speed and shadow details compared to Metol.
If someone interesting original Phenidone-Pyro formula - you can find it here: (there was a url link here which no longer exists)