Non staining Pyro developers? [Archive] - Large Format Photography Forum

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Shen45

2-Oct-2011, 15:32

sanking

2-Oct-2011, 16:50

Does anyone have any experience with non-staining Pyro developers. Are there any advantages or disadvantages compared to the staining type for ordinary photographic work. I understand many prefer the stain of Pyro developers for Alt processes.

Does anyone have any example of non staining Pyro developer formula.

Most, if not all, of the pyro staining and tanning developers can be formulated to not stain. You merely need to add enough sulfite and/or ascorbic acid and the stain will eventually go away. Pyrocatechin based developers are more sensitive to sulfite/ascorbic than those based on pyrogallol.

In general if you add more sulfite or ascorbic the energy of the developer will increase (shorter development times for the same contrast). The negative will also probably print differently on VC papers, and grain may be more pronounced because to some extent stain masks film grain.

You could make Pyrocat-HD a non-staining developer by increasing the amount of sulfite in the working solution by about 10X. I did these tests years ago and have forgotten the exact amount needed to kill the stain but I am pretty sure that about 10X will do it.

Sandy

Jay DeFehr

2-Oct-2011, 18:25

There are many pyro developers formulated for use in large tanks with replenishment. Farber's is one such developer, and judging by the formula, I wouldn't expect it to stain much, if at all, but PF claims it to be a staining developer. Pyro has long been prized for gradation, particularly by portraitists.

Shen45

2-Oct-2011, 21:34

Thanks Sandy and Jay. Does a non staining Pyro developer behave more like a normal developer and if so what are the advantages/disadvantages of that type of formulation over say a D76 type developer?

sanking

3-Oct-2011, 06:30

Thanks Sandy and Jay. Does a non staining Pyro developer behave more like a normal developer and if so what are the advantages/disadvantages of that type of formulation over say a D76 type developer?

I would say, yes, a non staining developer formulated with a reducer that has the potential to stain and tan (for example, pyrogallol, pyrocatechin and hydroquinone) could behave more or less like a normal developer like D76, if it is formulated appropriately.

The major issue would be, is the tanning also lost with the stain? If so, this would be a major loss because tanning, not stain, is responsible for the higher resolution of pyro staining and tanning developers.

Sandy

Jay DeFehr

3-Oct-2011, 11:49

Hi Steve,

Adding sulfite/ascorbate to a one-shot staining developer to remove the stain is different than formulating a developer for use in large tanks with replenishment. I can't comment with any authority on pyro based tank developers, and can only relate what I've read on the subject, which is that they were prized for their unique gradation, and used mainly for LF films, so grain wasn't a primary consideration, and some speed loss was common for any replenished tank developer.

I've formulated an ultra-fine grain, replenished tank developer that gives full film speed and excellent sharpness, but it's not a pyro developer, it's a ppd/ascorbate developer I call Halcyon.

I am curious about a pyro tank developer, but I'm skeptical one could match Halcyon.

Shen45

3-Oct-2011, 15:22

This is the non staining Pyro developer I formulated over the weekend. The results do have very nice tonal gradations as has been mentioned. Grain is very fine.

** There is a slight stain but nothing like the heavy stain of PMK
** Developer colour didn't alter apart from the anti halation backing.
** Very even development in BTZS tubes.
** I don't know how long the developer will store in its three individual bottled components.

Part A
1 gm Metol
2 gm Hydroquinone
3 gm Sodium Metabisulphite
5 gm Pyro
100ml

Part B:
20 gm Sodium Sulphite
100 ml

Part C:
Mix with room temperature water
5 gm Sodim Hydroxide
25 gm Borax
100 ml

1A+1B+2C+100ml water

Development times similar to PMK

* If you decide to mix this observe proper safety precautions for Pyro and other chemicals used.
* Gloves mask and eye protection.

Steve

3-Oct-2011, 19:42

I just had some nice experience with a new combination. I mixed up a liter of pyrocat-hd and developed a negative of fomapan 100 in a tray. It came out properly stained but less contrasty than I'd hoped for. I added ~~400ml of water and 2.5ml of hc110 concentrate, stirred it up and tossed in another negative. Developed real nice as a blend of what I'd like from both pyro and standard developers together, without strong telltale staining/tanning. Look forward to getting it dry so I can scan it!

sanking

3-Oct-2011, 19:59

Part B of this formula is a potential source of trouble because in storage the sodium sulfite will gradually change to sodium sulfate. When this happen you will get some additional general stain from oxidation.

This is one of the problems with the ABC Pyro formula.

Sandy

Shen45

4-Oct-2011, 00:09

sanking

4-Oct-2011, 10:30

Thanks for the comment Sandy. I have about 5kgs of Sodium Sulphite so could you give me a conservative estimate as to when I should consider remixing a fresh part B?

Could Ascorbic acid be used in place of the Sodium Sulphite and if so any estimate how much in 100 ml would be needed to reduce the stain?

Steve

Ascorbic acid will also go bad in solution with water.

You might consider just adding some ascorbic acid (or more metabisfultie) to Part A and dispense with Part B. This would require testing of course as the exact result of adding more ascorbic or metabisulfite to Part A can only be determined by empiric testing.

Sandy