Cinestill DF96 monobath

Raghu Kuvempunagar · Jun 22, 2021

Steve@f8 said:
The more I learn about this the more I want to know about the chemistry. Some reading is necessary and will ultimately help me get the best out of my ‘wet‘ photography.

Chapter 4 of "Modern Photographic Processing" Vol 2 by Grant Haist is a great read on monobath in case you want to learn more. A google search will lead you to downloadable copies. BTW monobath developing has been around at least since 1889. It is supposed to give very fine grain as may be expected from a solvent developer. But as Barry Thornton noted "unfortunately, for ordinary use, the weak shadow areas are fixed out before the developer can work and are largely lost". So additional exposure than normal is necessary to get best shadow detail. To get best results, the chemistry of a monobath needs to be tuned for each film (which neither Cinestill's nor Quall's monobath does BTW). Quoting from Haist: "The most commonly recurrent problem in formulating monobaths is the necessary precision of balance between developing and fixing reactions existing for various emulsion speeds to obtain optimum performance for any particular monobath. This ratio has been found to be a function of both the physical and chemical properties of the emulsion to be processed. For example, variations of emulsion thickness and grain size require different ratios. Silver chloride fixes faster than silver bromide, and even the presence of small amounts of silver iodide has an enormous retarding effect upon the fixing process." Further, single use monobaths are relatively expensive and reusable monobaths become inconsistent with use. These are some reasons why monobath developers went out of fashion.

Steve@f8 · Jun 22, 2021

Raghu Kuvempunagar said:
Chapter 4 of "Modern Photographic Processing" Vol 2 by Grant Haist is a great read on monobath in case you want to learn more. A google search will lead you to downloadable copies. BTW monobath developing has been around at least since 1889. It is supposed to give very fine grain as may be expected from a solvent developer. But as Barry Thornton noted "unfortunately, for ordinary use, the weak shadow areas are fixed out before the developer can work and are largely lost". So additional exposure than normal is necessary to get best shadow detail. To get best results, the chemistry of a monobath needs to be tuned for each film (which neither Cinestill's nor Quall's monobath does BTW). Further, single use monobaths are relatively expensive and reusable monobaths become inconsistent with use. These are some reasons why monobath developers went out of fashion.

Thank you.
Fine grain is not my liking, but my curiosity got the better of me to understand how two mutually exclusive aspects of film development could coexist, as it were.

I’m more interested in seeing visible grain, partly because it sets it apart from the digital output and partly because, well, I just like it. I’m in the process of kitting up to do home development and from what I’ve read i think I should be heading towards Rodinal, maybe 1:25 and agitating.

Huss · Jun 24, 2021

Steve@f8 said:
Thank you.
Fine grain is not my liking, but my curiosity got the better of me to understand how two mutually exclusive aspects of film development could coexist, as it were.

I’m more interested in seeing visible grain, partly because it sets it apart from the digital output and partly because, well, I just like it. I’m in the process of kitting up to do home development and from what I’ve read i think I should be heading towards Rodinal, maybe 1:25 and agitating.

Well then, that would be Kentmere 400 in DF96 Monobath

Steve@f8 · Jun 25, 2021

Would you say it has more to do with the development process (DF96 - temperature range 20 to 28C) than the film? Can you remember the temperature of development for the film above?
Hot development can induce visible grain with Rodinal, possibly with other developers.

Huss · Jun 25, 2021

Steve@f8 said:
Would you say it has more to do with the development process (DF96 - temperature range 20 to 28C) than the film? Can you remember the temperature of development for the film above?
Hot development can induce visible grain with Rodinal, possibly with other developers.

75 degrees

Steve@f8 · Jun 25, 2021

Huss said:
75 degrees

Quick calc, that’s about 24C. Not too warm as far as DF96 is concerned.
Interestingly, pushing is achieved by modulating temperature.

Donald Qualls · Jun 25, 2021

Steve@f8 said:
Interestingly, pushing is achieved by modulating temperature.

This is because temperature changes developer activity much more than it does fixer activity -- since Df96 (and all monobaths) is fixer mixed with developer, to push or pull you have to somehow adjust the ratio of activity of those two components. With Df96, Cinestill says that temperature controls development, and agitation controls fixing. Therefore, to develop more, you'd either developer warmer, or agitate less -- but after a couple rolls, agitating as little as one cycle per minute will cause bromide drag, so you raise the temperature instead, and agitate at least every 30 seconds (or continuously at another 5F warmer).

Steve@f8 · Jun 25, 2021

Thanks Donald.
Early today I read the DF96 data sheet, so no surprise what you say here.

(PS, I wish we could all use the same units of measurement. )

Donald Qualls · Jun 28, 2021

Steve@f8 said:
(PS, I wish we could all use the same units of measurement. )

Oddly, the USA has been and officially metric country for almost fifty years -- but never spent the money and effort to convert the minds of the people the way UK, Australia, India, and New Zealand did (you'll still find older folks in England who think in pounds/stone, Pound Sterling (including shillings, pence, and all those other oddball coins), degrees F, and feet/miles, but here that's pretty much everyone who isn't a scientist or engineer).

Steve@f8 · Jun 28, 2021

Donald Qualls said:
Oddly, the USA has been and officially metric country for almost fifty years -- but never spent the money and effort to convert the minds of the people the way UK, Australia, India, and New Zealand did (you'll still find older folks in England who think in pounds/stone, Pound Sterling (including shillings, pence, and all those other oddball coins), degrees F, and feet/miles, but here that's pretty much everyone who isn't a scientist or engineer).

I suppose some would say I’m of an age to put me in the group still using LSD (not the drug ) but I only refer to the defunct currency when joking and crossing units, eg someone may say your weight is xKg and I respond (childishly) ‘what’s that in pounds shillings and pence’, ie st and lbs.

I was in a tech meeting in the USA some time back and we were discussing activation energy of a process. I can only think in SI units, ie kJ/mol, but my American counterpart constantly referred to calories/mole. Conversions were flying backwards and forwards. Similarly I can only think straight in other metric units, linear measurement, temperature, force, etc etc. Fully SI here.

Donald Qualls · Jun 28, 2021

I took engineering coursework around 1980 (before dropping out of college), so I learned lots of conversions and keep them in my head -- just this past weekend, I was figuring out what a cubic yard of stone weighs by remembering 62.4 pounds per cubic foot for sea water, then 2.5% salt by weight, then a rough figure of 3 to 5 for specific gravity of stone (turns out that's high, it's more like 2.5 for common building stone). I used to do problems with givens in slugs, kilometers, BTUs, and sometimes poundals -- and I know most of the relevant conversions (in two or three steps, sometimes).

Huss · Jun 29, 2021

Steve@f8 said:
Quick calc, that’s about 24C. Not too warm as far as DF96 is concerned.
Interestingly, pushing is achieved by modulating temperature.

No not too warm, and when I develop HP5+ the exact same way, it has much finer grain than the Kentmere pic.
So if you want more visible grain, Kentmere is the way to go.

Steve@f8 · Jun 30, 2021

Huss said:
No not too warm, and when I develop HP5+ the exact same way, it has much finer grain than the Kentmere pic.
So if you want more visible grain, Kentmere is the way to go.

I might give it a go, but first (when I finish acquiring the equipment for B&W development) I hope to try +30C hot development in Rodinal.

Robino Jones · Jun 30, 2021

Hi Everyone - first post here, been experimenting processing 16mm with DIY monobath (also Cinestill) and I was informed by a facebook user that I was using Donald Qualls monobath recipe. Thanks a lot Donald for your recipe and contributions.

I'm getting little spots that look like cells. there's a white dot in the center with an orb around it. film is old expired plus-X. This is the recipe I found online, I don't recall where.

40ml of Ilford RapidFix
65ml of HC110
200ml of clear ammonia
Top to 1000ml with water.

When using the D96 monobath from Cinestill I don't get these orbs.I was thinking maybe the unfiltered / distilled tap water I use could be the issue but using same water with regular D96 powder and development process (develop, stop, fix, wash) I never get orbs.

First time I tried, I was using scented ammonia which gave orbs as well.. I thought It was the extra chemicals in the lemon ammonia causing the orbs but using clear ammonia had the same results.

What do you guys think it is? see screenshots.

Raghu Kuvempunagar · Jul 5, 2021

This summarizes the practical problems with monobaths, image quality aside:

David A. Goldfarb said:
The problem with a monobath is that without exotic and expensive chemicals, it tends to self-destruct once you start using it, so you have to mix it up and use it in one session, or at most within two days, or fixed out silver, the fixer, and the developer all start interacting to produce sludge and to exhaust the developer. You also need kind of a lot of developing agent to compete with the fixer, so it could get costly in large quantities.

Huss · Jul 6, 2021

Raghu Kuvempunagar said:
This summarizes the practical problems with monobaths, image quality aside:

Except it doesn't because he is incorrect with a lot of his statements. It has to be used within 2 days? Seriously?
Anyway....

Chinon Bellami, Arista 100, Cinestill DF96 Monobath

Roll #14 from a bottle that was opened June 8.

janew · Jul 14, 2021

Raghu Kuvempunagar said:
This summarizes the practical problems with monobaths, image quality aside:

Well no it doesn't. You've got to use Df96 within two months, or for a maximum of 16 rolls of film. (And my guess is that you can stretch it out longer.) That doesn't strike me as a huge problem at all.

Huss · Jul 14, 2021

Leica M3, Summicron 40mm f2, Arista 100, Cinestill DF96 Monobath

"The Old Man and the Sea"

Huss · Jul 14, 2021

Nikon LiteTouch AF set to pano mode, Arista 100, Cinestill DF96 Monobath

Raghu Kuvempunagar · Jul 15, 2021

janew said:
Well no it doesn't. You've got to use Df96 within two months, or for a maximum of 16 rolls of film. (And my guess is that you can stretch it out longer.) That doesn't strike me as a huge problem at all.

David's observation was for home-brew monobaths based on his extensive experimentation. Maybe DF96 uses some exotic ingredients, not available to home brewers, that prevent the monobath from getting spoilt quickly. But in this very thread some people have complained that DF96 gives inconsistent results on the same film with repeated use. Unless somebody does a rigorous testing of DF96 after every few rolls and compare the results, not much can be said conclusively about it keeping well and giving consistent results throughout its life time. However, if it's working fine for you, great!

Donald Qualls · Jul 15, 2021

In my (limited, one batch to date, mixed from dry package -- mentioned because that might be slightly different from what's sold in a jug) experience, Df96 is pretty good right up until it isn't. Mine was right on two months old with 12 or 13 rolls processed when it just quit. I'm probably not the right guy to ask about "consistent," though; I don't do sensitometry, quite often use Sunny 16 instead of metering, and haven't made a wet print since I came back to film a little over a year ago.

Huss · Jul 15, 2021

Leica M3, Summicron 40, Arista 100, DF96 Monobath

Huss · Jul 19, 2021

Nikonos V, 35 2.5, Arista 100, Cinestill DF96 Monobath

"Solitude"

Huss · Jul 30, 2021

Lomo LC-A 120, Arista 200, Cinestill DF96 monobath

Huss · Sep 3, 2021

Chinon Bellami, Ilford HP5, Cinestill DF96 Monobath

Cinestill DF96 monobath

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