New film developer idea (all powder!)

[Ryuji]

I’m setting up a film processing station in my new commercial photo studio. I think I’m going back to all powder formulation, like I used to with DS-1 and DS-2. For small scale film processing, powder formulation offers more advantages than liquid concentrates, including long keeping properties. I’d rather weigh powder mix than viscous stock.

I’d probably formulate like this:

Part A:
ascorbic acid
Phenidone (or Dimezone S)
one or more water soluble polymers (cellulose derivatives, vinyl derivatives, and of course polyvinylpyrrolidone) and/or sugar alcohols (sorbitol, xylitol, etc).
any other additives

Part B:
sodium sulfite
borax
developer stabilizer additive

The only tricky part here is how to ensure uniform mix and prevent segregation in Part A. I think one or more water soluble polymers with suitable molecular weight and particle size can be used to “dilute” Phenidone first, wherein the Phenidone and polymer form cohesive aggregates. This is then mixed with the rest of ingredients in Part A. With this level of care in formulation, it is okay to just stir the jar before use.

Some of the water soluble polymers are actually known to improve image quality. Viscous developers are known to increase accutance and reduce granularity, although incompatible with spiral tank processing. I’m probably going to use polymers that are not viscous for this project, but something that has other effects, such as lower fog level and cleaner highlights. In the past, I experimented using several kinds of polymers in liquid concentrate stocks, but these polymers do not dissolve well in a concentrated sulfite solution. So, I often had to add them to the working solution. Powder formulation can just solve that problem altogether.

Another advantage of powder formulation is that we don’t need glycols and other solvents, and don’t need to handle viscous liquids. About the only and small negative is that I have to give up my favorite ethanolamine mix and go back to Borax.

If this approach works, I think it’s just a matter of stirring powder mix A in a jar, take 6 grams, take 50g of B, dissolve in a liter of cold tap water, adjust the temperature and it’s ready to go. (Numbers are just made up but they are realistic range.) This will be easier to dissolve than D-76 (stuff will dissolve while loading films into tank). I’d probably keep mix A in a vacuum jar to prevent moisture caking and oxidation.

Added bonus is that I can have a Part C, which can be used in place of Part B, to make a different developer. I’m most likely making Part B for fine grain (400+ speed films) and Part C for accutance (100 speed films), just like what I used to do with DS-1 and DS-2.

What do you guys think?

[Kirk Keyes]

Won't you just run into the old issue of particle separation due to bulk density? I suppose if your polymer can be coated uniformly then you have a chance of it working.

How's this idea - find a matrix that is soluble in both solvent and water and then dissolve your phenidone and ascorbic into it with the solvent. Pour the solution out into a tray and let the solvent evaporate. Then grind the matrix to a fairly uniform particle size so that it quickly dissolves in water. Then you can pretty much be assured of uniform distribution of your developing agents in your matrix.

Kirk

PS - glad to see you back here!

[Ryuji]

Won't you just run into the old issue of particle separation due to bulk density?

That’s more likely if sulfite and borax are mixed together with developing agents, so I expect less problem with my strategy. But it remains to be tested.

How's this idea - find a matrix that is soluble in both solvent and water and then dissolve your phenidone and ascorbic into it with the solvent. Pour the solution out into a tray and let the solvent evaporate. Then grind the matrix to a fairly uniform particle size so that it quickly dissolves in water. Then you can pretty much be assured of uniform distribution of your developing agents in your matrix.

That’s too much work :-)
It’s more work than weighing individual ingredients each time I develop.

If this were a $500k/yr business, I’d probably use a tablet press to punch out tablets. But I’m looking for a good small scale processing solution...

[John Austin]

This lot does my head in - If you only process BW in small batches get some Rodinal, not the magic brew some claim, but it does work - Leave your head clear for making images

[jnanian]

Ryuji


too bad it has to be mixed / suspended into a liquid
i have often wished there could be just a powder to submerge
my film into, no liquids ... and
after " x minutes " it would be ready to fix ...
when i read the title of your thread, i thought my wish had come true !

happy holidays !
john

[jnanian]

This lot does my head in - If you only process BW in small batches get some Rodinal, not the magic brew some claim, but it does work - Leave your head clear for making images

hi jbaphoto:

you might not realize .. but Ryuji is an inventor of developers
and maker of emulsions ... i haven't used his magic brews
but from all reports they work well, very well !

john

[Ryuji]

too bad it has to be mixed / suspended into a liquid
i have often wished there could be just a powder to submerge
my film into, no liquids ... and
after " x minutes " it would be ready to fix ...
when i read the title of your thread, i thought my wish had come true !

Ha! I don't know how to do that but that's not a bad idea... It'd be hard to pour powder to your tank though.

[Kirk Keyes]

It'd be hard to pour powder to your tank though.

That's where your Jobo rotary processor comes in handy!

[Ryuji]

I actually never owned a Jobo. It'd be a good idea but it's still expensive...

[Crashbox]

This sounds quite interesting, I wish you complete success with it.

Experimenting with developers is nothing but fun in my opinion-