Plea to APUG chemists and photographic engineers

[jp498]

I'm not a chemist. I was wondering if we could add instant coffee to xtol or another non-staining developer of choice to make it a caffenol-blend.

I mixed up some coffee with developer the other day to try an 8x10 in. After I turned out the lights, I accidentally slipped the 8x10 sheet of film into the fixer instead of the prewash water. End of that opportunity.

I'm not sure what 35mm film the OP is using, but I think 35mm tmy2 works great with PMK without being grainy.

[Gerald C Koch]

I'm not a chemist. I was wondering if we could add instant coffee to xtol or another non-staining developer of choice to make it a caffenol-blend.

I mixed up some coffee with developer the other day to try an 8x10 in. After I turned out the lights, I accidentally slipped the 8x10 sheet of film into the fixer instead of the prewash water. End of that opportunity.

I'm not sure what 35mm film the OP is using, but I think 35mm tmy2 works great with PMK without being grainy.

No, with coffee what you would get would be an overall stain. What you want is a stain that is proportional to the amount of developed silver.

[Photo Engineer]

Ok, here is what you want. Get Citrazinic acid, H-Acid or J-Acid. These are water soluble couplers that form greenish yellow dyes. Presoak your exposed B&W film in a solution of Epsom salts + Alkali + one of the above acids. This will cause them to stick to the film (mordant) in the gelatin. Then rinse briefly. Then run through the C41 process (no bleach or blix, just a fix) at room temp. If things go as expected you will get a black and green image.

This should work. It works in parts and pieces, as I have done it before, but don't ask for specifics. If you want this, you must do the experiments yourself. Sorry.

PE

[Gerald C Koch]

Thanks PE I knew you could say it better than I could.

[michaelbsc]

Michael, what you want to know about is dye-mordanting techniques. There are ways to do exactly what you want; stain an image in proportion to its silver ....

Chris,

How well is this likely to work with modern T grain and thin emulsion like Delta 400 or Tmax?

It ssems like the lower silver content as well as the lack of emulsion to absorb stain both work against you.

Do I understand this correctly? Or should I review the concepts again because I missed it?

[Photo Engineer]

Unfortunately, mordanting does not work imagewise!

PE

[michaelbsc]

Unfortunately, mordanting does not work imagewise!

PE

Pity. Sounded interesting.

[Photo Engineer]

It could probably be made to do so by some hard work by a synthetic organic chemist and a team of engineers!

PE

[desertrat]

There is a dye intensification process for negatives mentioned in Photographic Facts and Formulas, by E. J. Wall, 1924:

Partially bleach the fixed and washed negatives in:

Potassium Ferricyanide, 0.34 grams
Ammonium Dichromate, 0.068 grams
Glacial Acetic Acid, 8,5 ml
Water, 1000 ml

Then wash, and immerse in:

Victoria Green (Malachite Green) 0.26 gram
Safranin, 0.52 gram
Glacial Acetic acid, 8.5 ml
Water, 1000 ml

Dye for 30 to 120 seconds and wash for 5 minutes.

You can probably substitute Potassium dichromate from a chromium intensifier kit for the ammonium dichromate. You can probably also use indicator stop bath concentrate instead of glacial acetic acid and use twice (17 ml) as much. Dry malachite green and safranin stains can be bought from some biological or chemical supply houses. One that sells to individuals, but has a long lead time on delivery, is elementalscientific.net. I've bought from them, and always got what I ordered, but sometime it takes a couple of months. I think Artcraft will custom order things they don't stock on a quote. A solution of malachite green can be bought at some aquarium stores for treating certain skin infections of fish. The amount to use would have to be determined by trial and error. You might be able to get by with just the green dye without the safranin, which I think is red.

The amount of time to 'partially bleach' the images would have to be determined by trial and error. I have no idea how well this would work with modern films, but it might be a fun experiment.

[holmburgers]

Unfortunately, mordanting does not work imagewise!

PE

PE, I'm not so sure if that's correct. There are a number of dye-mordanting color processes from the past, like Uvachrome (go down the page).

Ive's also used a similar process for his Kromskop images, and if I'm not mistaken (which could be a big if), J.S. Friedman's "Dye-Toning" technique works similarly.

Here is what it says on page 340, 2nd ed. 1945, "...Mr. Miller decided that if the silver of the image is converted into silver iodide in the presence of high concentrations of potassium iodide, a completely transparent silver iodide-potassium iodide mordant is formed... When bleached in this solution, a completely invisible image composed of a complex potassium silver iodide, is formed, an image which absorbs dye..."

This works for basic dyes, like malachite green, and would definitely be image-wise.