Ultra Rapid Monobath

[Ian Grant]

Ian Grant submitted a new resource:

(there was a url link here which no longer exists) - Ultra Rapid Monobath

Potassium Sulphite 20 g
Antinomy Potassium Tartrate 40 g
Phenidone 3 g
Hydroquinone 60 g
alpha-Thioglycerol 150 ml
Water to 1 litre

Will process Kodak Plus-X Reversal in 2.5 seconds @ 48°C and give similar results to the film processed in D19

(there was a url link here which no longer exists)

 

[David A. Goldfarb]

Thanks for another addition to the collection. I don't think I need that kind of speed, but out of curiosity, I looked up sources for antimony potassium tartrate and alpha-Thioglycerol, and they seem pretty expensive ($73/125 g of antimony potassium tartrate and about $11/g of alpha-Thioglycerol).

Since I saw it sold by the gram, what is the concentration of alpha-Thioglycerol, and what does it do in the formula?

"Antinomy"?--Kant wrote about them in the First Critique.

 

[Ian Grant]

The reference doesn't state the strength the alpha-Thioglycerol, it's the stabilising agent - the fixing agent.

I only posted this in response to another article on a High Speed fixer

 

[David A. Goldfarb]

I see, well, this beats the high speed fixers.

 

[Ian Grant]

When I'm next in the UK I'll pay a visit to a lab that may have those two chemicals (we bought everything from a redundant Research Lab AA, ICP etc etc, lab fittings and the complete chemical store !!!!).

I know I had an Antimony lamp for my AA so must have had some standards etc.

 

[Photo Engineer]

Note the temperature.

Many modern fixers will work rapidly at 48C. In fact, you better have a very hard film.

The Antimony salt probably helps harden here just as Zirconium salts can under some conditions.

I could probably formulat a fixer that did this at 75 degrees as well, but the price would be high. (well, this one does not come cheap either I guess.)

Interesting formula Ian.

PE

 

[2F/2F]

Will it work at my normal temp of 24C or 20C?

 

[David A. Goldfarb]

In my experience, monobaths are pretty temperature sensitive. You can't control contrast by processing time, but changing temperature will change contrast significantly.