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Monobath Developers

I am about to dunk my first monobath ever... 5x7 Arista EDu-100 shot of a doggie...
Stay tuned the Developer is "cooling" to 75. I still think this is daff, but seing it has some history and isn't some "steam punk-hipster" idea of the day, I'm diving in.
 
We'll that was a strange experience, but great way to do sheet film.
Results... I shot a black and white dog on a white background. They look to be 1 stop under, so rather than 100 I'll rate as 50 next time, I may not have compensated enough for bellows extension either.
Different smells in the darkroom, with the NH3 in the air.

My daughter came in the studio... 2 more 5x7 sheets shot and developed in less than 20 minutes. These look printable.
Still a little thin... gonna rate this at 25ish

Oh what I am doing..
Tray almost no agitation @ 75F
15ml of hc110
50ml NH3 household strength
10ml Ilford rapid fix concentrate
H2O to make 250ml

I do 2 5x7 sheets and toss out... anyone go 3 or 4?
 
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IDK where you got the formula, but I would not use Ammonia in a developer for a modern film. Even the fix you use should be ammonia free. Most people do not know or use this simple guideline.

Ammonia is a fogging agent that also speeds the fixing reaction. It is also a strong base that raises the pH.

PE
 

Could you use Sodium Carbonate as a strong base rather than the Ammonia?
 
Most of the formulas I've looked at use sodium hydroxide, which is no longer available at the grocery store, but can be obtained from suppliers of bulk chemicals.
 
The origin of the monobath formula is Oct. 9, 2004, Donald Qualls posted, in rec.photo.darkroom, the following description of a monobath based on HC-110. It also appears on the covington hc-110 website.
 
I agree with David. Also, use Sodium Thiosulfate instead of rapid fixers which use Ammonium Thiosulfate.

See the original formulas on page 1 of this thread.

PE
 
The problem with monobaths is that they must be adjusted for each and every film in order for them to produce useful results. This more than anything else led to their disuse. The Poloroid process of course does not have this problem since the film and monobath are designed for each other.
 
I had not really thought much about Monobath developers until now- just noticed that the New55 people are offering a Monobath developer here: Dead Link Removed
 
Haist seems to be the expert on thissubject and he covers it with aformula in 'Modern Photographic Processing'I never tried it.PE ma be able to elaborate on the subject.
 
I did a lot of commercial work on Monobaths in the late 1970's if the formula is fine tuned for a specific emulsion the results can be excellent.

Russian photochemists were at the forefront of Monobath research and applied uses, I have a very detailed article which gives a good overview of Monobaths somewhere.

Ian
 
Thanks!
 
Very cool to see a commercial monobath available. I think I'll stick with FX6a, if I get back to using monobaths again, but the sample photos have that Type 55 monobath neg look. I think it's an edge effect thing.
 
David A. Goldfarb said:
Very cool to see a commercial monobath available. I think I'll stick with FX6a, if I get back to using monobaths again, but the sample photos have that Type 55 monobath neg look. I think it's an edge effect thing.
Click to expand...

As contrasted with normal development monbath development in confined to a very thin layer near the surface of the emulsion. This may account for the different look. All this is explained in Haist's book.
 
One question about New 55's R3 monobath is whether it generates sludge once it's used. This seems to me to be the biggest drawback of monobaths. Haist proposes a solution in the Monobath Manual, but it involves sequestering agents that are expensive and not as easy to obtain as other photographic chemicals for the small scale user. A commercial manufacturer, however, might be able to obtain these materials to make the solution last longer, and that would be a real improvement over a formula like FX6a.

An attraction of FX6a, however, is that you can adjust the hypo concentration to calibrate the monobath to the film. An ideal commercial monobath would be something you could calibrate in this way (say by keeping the hypo separate, and you could add more to reduce the amount of development for a given film) and with the exotic chemistry needed to extend the usable life of the solution.
 
I am not sure, but I think that Grant finally concluded that a 2 part film system was the answer. Kind of like image transfer or instant imaging? He saw commercialization problems I think.

PE
 
Years ago I tried Haist's MM-1 monobath with Kodak Plus-X and it worked quite well. But again the question for the average user is "Just what do you save over conventional develop and fix?" A small amount of time but at greater expense.
 
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Monobaths are best for applied uses as there is little need for tight temperature & time control, between about 15ºC-27ºC. They have been used for military & space applications, as well as Polaroid, Xray films, Microfilms etc.

I worked on them so that potentially with a given emulsion the only user variable was exposure, and the monobath took away the parameter of under or over development over a manageable temperature range (15ºC-27ºC).

Geoffrey Crawley's FX6a monobath works well and can be fine tuned to match specific films. L F A Mason in Photographic Processing Chemistry lists a typical Monobath formula. Mason was head of Research at Ilford, his editor was G I P Levenson who held a similar position at Kodak Ltd (UK).

Typical Monobath

Sodium Sulphite (anhyd) 50g
Hydroquinone 15g
Phenidone 10g
Potash Alum 18g
Sodium Hydroxide 18g
Sodium Thiosulphate (5H20) 210g
Water to 1 litre

Water must be softened or deionised/distilled to prevent precipitates.

Use 1+1, 600ml working solution will process 6 rolls of 35mm/120 film, minimum Development time 7½ mins between 15.5ºC/60ºF and 26.5ºC/80ºF

I've not tried this particular monobath but suspect it's similar to Ilford's Monophen which they sold commercially.

Ian
 

The above formula is similar to Alburger's Aluminate Monobath given in The Monobath Manual. However the book erroneously omits the thiosulfate.
 
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