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Shen45
1-Nov-2013, 22:01
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" 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 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.