Adotech III vs. Adotech IV for Processing CMS 20 II

[Scott J.]

Howdy,

I'm hoping someone can clarify the difference (if any) between Adotech III and Adotech IV in terms of their impact on image quality when used to develop CMS 20 II film. The descriptions for these two developers on various internet retailers is confusing, in that the descriptions for each product seem to discuss both developers interchangeably, to the extent that it's difficult to know just which developer is being described at any one time. The only definitive differences I can see are in the prescribed dilutions and film capacities -- i.e., Adotech III is supposed to be mixed 1+9 to develop four 35mm films, while Adotech IV is mixed 1+14 to develop six 35mm films. I'm tempted to conclude that the developers are essentially identical in terms of their performance and composition, but that Adotech IV is simply a more concentrated solution.

Adotech III seems to be the only one of the two that is regularly available. Is there any advantage to waiting to get my hands on Adotech IV before shooting some CMS 20 II?

 

[ADOX Fotoimpex]

Howdy,
I'm tempted to conclude that the developers are essentially identical in terms of their performance and composition, but that Adotech IV is simply a more concentrated solution.

No. In this case we would not have released it. ADOTECH has been upgraded IV times by now and each new version was superior to the older ones.
The main advantage of IV vs. III is a better speed utilisation. Older version improvements were mainly about the usability and getting high resolution photography to work stable at all.
Since this is now all set up we focused more on the speed utilisation and tweaked the developer even a bit more.
It is important to follow the temperature requirements and it is also important that the developer cools down during the process. The 1/3 rd stop of effective extra speed will not be there if you keep the temperature at 24°C over the entire processing time.

Mirko

 

[pentaxuser]

.
It is important to follow the temperature requirements and it is also important that the developer cools down during the process. The 1/3 rd stop of effective extra speed will not be there if you keep the temperature at 24°C over the entire processing time.

Mirko

I was only able to find the instructions in German but with the aid of a dictionary I think that allowing the developer to cool down is only a requirement when you seek use ISO 25?. The developer then cools down from 26C to the room temperature of 20-21C and presumably the correct cooling rate to achieve this speed increase of 1/3rd stop is based on the known cooling rate that takes place over the 11mins of development time.

Have I got this right?

Secondly if your darkroom in Summer is at an ambient temperature of 26C so no cooling process from the room temperature then can you place your tank in water at 20C to achieve the correct cooling rate or does it require experimentation with water at different temperatures to get a steady drop to 20C over 11 mins?

So finally based on my assumptions above, if you are happy with ISO 20 then this simplifies matters a lot as you can ignore any need to ensure that cooling down takes place.

While Mirko is clearly the best person to answer these questions. any other German speaker can perhaps say if I have understood correctly what is in the processing instructions

Thanks

pentaxuser

 

[Scott J.]

The instructions for Adotech IV make only a passing reference to allowing the film to cool down from the initial developing temperature. Unfortunately, they don't quantify how much cooling should occur (i.e., final temperature, rate of temperature decrease, etc.). Here's the relevant passage (roughly translated):

"The dilution always remains constant at 1+14. The different film sensitivities are accomplished through variation of the development temperature, agitation, and development time. Important: All temperature data represent the filling temperature of the working solution. Constant maintenance of this temperature (e.g., via warm water bath) during the development is not required, and may actually distort results. It is only necessary to develop in a room at a normal room temperature of about 20° C to 21° C. When developed during the summer at higher room temperatures, the development time must be reduced accordingly. It should be noted that the development time must be reduced by larger and larger amounts to counteract higher and higher room temperature and filling temperature. Preheating is not required and could change the contrast."

The instructions then list a table of different ISO speeds, filling temperatures, and developments times:

ISO	Dilution	Filling Temperature	Developing Time(min)	Agitation (Constant for first 30 sec., thereafter	Contrast
3	1+14	20 C	7.5	Once per minute	Normal (N)
6	1+14	20 C	10.5-11.0	Once per minute	Normal (N)
10	1+14	22 C	10.5	Once per minute	Normal (N)
12	1+14	23 C	10.0	Once per minute	Normal (N)
20	1+14	24 C	11.0	Once every 2 minutes	Normal (N)
25	1+14	26 C	11.0	Once every 2 minutes	Slightly increased (N+0.5)

My guess is that, during film testing, Adox determined that maintaining the development temperature at the initial filling temperature increased the contrast too much, such that they now recommend letting the system cool down gradually during development. Obviously, this only applies to film that was exposed at the higher ISO settings in the table above (i.e., ISOs 12-25), as those are the only development situations in which your initial filling temperature should experience any cooling in a room at 20-21 degrees C. On that point, I notice there's an inflection point in the development time for ISO 12. I interpret that to mean that Adox noticed something in their film testing about how the higher ISOs (12-25) behaved a little differently during development, and consequently, required slightly special care.

The imprecision of the instructions is probably a bit frustrating to some film photographers (many of us tend to be detail-oriented, engineering types), but I'm guess that Adox has tried to simplify things by making some basic assumptions about the average rate of cooling that one would observe given a typical development tank (e.g., a Paterson tank) and solution volume (e.g., 250 mL). Obviously, changing any of the relevant variables is going to impact the rate of cooling and the final temperature (cf. Newton's cooling law), but the takeaway appears to be that there probably isn't a huge impact from one scenario to another given a "normal" set of starting conditions.

I think your idea to submerge in a water bath at 20-21 degrees C in warm weather is probably a good approach, with perhaps one caveat: doing so might result in too much cooling (water has a higher specific heat and thermal conductivity than air). You might consider submerging in a water bath at, say, 22-23 degrees C, or conversely, intermittently submerging in 20 degrees C (i.e., one minute in, one minute out). I'd be curious to see how much impact this actually has on the images versus simply developing at 26 degrees C with no cooling. A warm room like yours or a Jobo TBE-2 would seem ideal to facilitate such a test.

 

[pentaxuser]

Thanks, Scott, for that comprehensive reply. I wonder if Mirko will reply and confirm or modify as the case may be, your conclusions. Given the claims for this film's resolution and there does seem to be some basis for the claims in sample pictures, it has surprised me to some extent that the film and developer hasn't a bigger following in the U.S. where for a lot of the year and in a lot of states the bright sunlight allows reasonable shutter speeds without wide-open apertures.

pentaxuser

 

[ADOX Fotoimpex]

I was only able to find the instructions in German but with the aid of a dictionary I think that allowing the developer to cool down is only a requirement when you seek use ISO 25?. The developer then cools down from 26C to the room temperature of 20-21C and presumably the correct cooling rate to achieve this speed increase of 1/3rd stop is based on the known cooling rate that takes place over the 11mins of development time.

Have I got this right?

Secondly if your darkroom in Summer is at an ambient temperature of 26C so no cooling process from the room temperature then can you place your tank in water at 20C to achieve the correct cooling rate or does it require experimentation with water at different temperatures to get a steady drop to 20C over 11 mins?

So finally based on my assumptions above, if you are happy with ISO 20 then this simplifies matters a lot as you can ignore any need to ensure that cooling down takes place.

While Mirko is clearly the best person to answer these questions. any other German speaker can perhaps say if I have understood correctly what is in the processing instructions

Thanks

pentaxuser

As you can see from the table the starting temperature increases with ISO. So yes you would only need 26° and a coresponding cooling rate @ 25 ASA but e.g. at 20 ASA it is still 24°C and a cooling to about 20°C. Only if you expose the film at 6 ASA (which is the best quality) you can start and remain at 20°C. We discussed the problem of a hot room in the summer. There is no data on this yet. Our recomendation is to go into the basement, wait until fall or expose below 20 ASA ;-)
Seriously. We are on the edge of physics here with this imaging system. Some compromises have to be made.

Mirko

 

[Old-N-Feeble]

Mirko, why the need to start development warm and let it cool? This is a difficult variable to control consistently.

 

[ADOX Fotoimpex]

You need the high starting temperature to crank the speed and you want it to cool down for compensating reasons. If you stayed at 26°C your contrast would be to high. If you started at 20°C you would not achieve the desired ISO (no real 25 ASA ascording to ANSI. There are limitations but it works in a pictorial way).
We do not think this is such a big deal. Just make sure your room temperature is about 20..21°C (or even as bit less), dilute the developer in 26,5°C warm water and there you go.

Mirko

 

[pentaxuser]

We do not think this is such a big deal. Just make sure your room temperature is about 20..21°C (or even as bit less), dilute the developer in 26,5°C warm water and there you go.

Mirko

Thanks Mirko and you are right for most of the year for the U.K...in fact even in average U.K summers, especially in Scotland, an ambient room temperature of 20-21 during mid to late evening is usually perfectly possible. However in the U.K. at the moment we are currently going through a hot period which has lasted a few weeks when 20C room temperature is just about possible for a couple of hours in the middle of the night

pentaxuser

 

[Old-N-Feeble]

Daytime highs here are 35-38C and rising. I predict we'll see a few 42 degree days this summer. The air conditioner can't cool this old mobile home to 20C even during the coolest night hours for at least half the year.

 

[ADOX Fotoimpex]

Daytime highs here are 35-38C and rising. I predict we'll see a few 42 degree days this summer. The air conditioner can't cool this old mobile home to 20C even during the coolest night hours for at least half the year.

But then you can´t develop any B&W film to a regular contrast....

 

[alentine]

A photo of real print example from CMS20, would be appreciated.
Thanks.

 

[Sal Santamaura]

...Only if you expose the film at 6 ASA (which is the best quality) you can start and remain at 20°C...

Nearly two years later, a follow up question. Is there any reason why, if CMS 20 II is exposed at the optimum EI 6, one cannot develop it in Adotech IV by starting and remaining at some higher temperature that follows conventional time/temperature equivalence tables? For example, instead of 10.5 -11.0 minutes at 20 C, 7.25 - 7.5 minutes at 24 C. Thanks in advance Mirko.

 

[ADOX Fotoimpex]

Nearly two years later, a follow up question. Is there any reason why, if CMS 20 II is exposed at the optimum EI 6, one cannot develop it in Adotech IV by starting and remaining at some higher temperature that follows conventional time/temperature equivalence tables? For example, instead of 10.5 -11.0 minutes at 20 C, 7.25 - 7.5 minutes at 24 C. Thanks in advance Mirko.

In theory yes this should be possible. You can aproach the developing time with the known temperature rules to determine a starting point and then tweak your development in. Will we not be testing this however. The speed increasing effect of the developer cool down is not needed here. Basically what happens is that some developers have different kinetics at different temps. Starting at the higher temperature lifts your shaddows (steeper curve more effect in the toe "brings the shaddows up"). Ending with a lower retains your highlights from blocking (lowered curve longer shoulder). So you can expose less and still have shaddow detail while not completely blowing highlights with the same gradation in the middle part. Exposed to 6 ASA you need neither of this. At this sped all you need to care for is the middle part. This makes it easier.

 

[Raghu Kuvempunagar]

Exposed to 6 ASA you need neither of this. At this sped all you need to care for is the middle part. This makes it easier.

At EI:6 one probably need not use the special purpose Adotech developer either! Cafenol, for instance, does well going by many examples shared by several photographers. I thought the whole idea of using the special purpose developer was to get the otherwise elusive speed of 20.

 

[ADOX Fotoimpex]

At EI:6 one probably need not use the special purpose Adotech developer either! Cafenol, for instance, does well going by many examples shared by several photographers. I thought the whole idea of using the special purpose developer was to get the otherwise elusive speed of 20.

In direct comparison you see a lot of difference even at 6 ASA. What you say becomes relevant at about 1-2 ASA.

 

[Sal Santamaura]

Nearly two years later, a follow up question. Is there any reason why, if CMS 20 II is exposed at the optimum EI 6, one cannot develop it in Adotech IV by starting and remaining at some higher temperature that follows conventional time/temperature equivalence tables? For example, instead of 10.5 -11.0 minutes at 20 C, 7.25 - 7.5 minutes at 24 C. Thanks in advance Mirko.

In theory yes this should be possible. You can aproach the developing time with the known temperature rules to determine a starting point and then tweak your development in...

Thanks again, Mirko. I just ordered the bundle of five CMS 20 II rolls plus one bottle of Adotech IV

https://www.fotoimpex.com/films/bun...or-up-to-6-35mm-or-120-films-100-ml-conc.html​

and will reply here whenever my development time tweaking is complete.

In another thread, Henning Serger wrote last Wednesday:

...I've just recently talked to FOTOIMPEX and they told me that meanwhile the shipping situation has improved significantly concerning speed, as the backlog of the hub in New Jersey has been reduced (that was the main problem). The latest orders only needed about 2-3 weeks from Germany to the US. Much less time than during the winter...

I'll reply here when DHL and the USPS actually deliver that order. I'm not optimistic, but will keep an open mind. We shall see.

 

[Henning Serger]

At EI:6 one probably need not use the special purpose Adotech developer either! Cafenol, for instance, does well going by many examples shared by several photographers. I thought the whole idea of using the special purpose developer was to get the otherwise elusive speed of 20.

I have used this film a lot at different Exposure Indices, including EI 6. And I cannot recommend Caffenol.
Best results at that EI I have got with Adotech IV developer, followed by Rodinal 1+99(100).

Best regards,
Henning

 

[Raghu Kuvempunagar]

I have used this film a lot at different Exposure Indices, including EI 6. And I cannot recommend Caffenol.
Best results at that EI I have got with Adotech IV developer, followed by Rodinal 1+99(100).

Thanks for sharing your experience. Very insightful as always. I'll make note of Rodinal 1+99.

 

[Andrew O'Neill]

I've tried several developers with this film (4x5)... D-23 very diluted, POTA (acceptable), Pyrocat-HD (didn't like results), Caffenol (muddy). In the end, Adotech IV gave the best results.

 

[m00dawg]

Hmm bring up a good question - if I'm after a good pictoral result more than ISO speeds, what would be a realistic ISO to consider? Apart from reciprocity, I'm not really bothered by low ISO and expect that I would be using CMS 20 situations where I can be slow and methodical (and on a tripod). I've ordered a handful of rolls along with Adotech IV to try it out. I too tend to have a problem with getting my room cold enough in the summer to cool the developer down (in fact would have an issue with it potentially warming up). But if that's only needed for reaching the higher speeds, I have no problem shooting at a much lower ISO and in fact kinda expected I would want to rate CMS 20 more slowly anyway.

 

[Raghu Kuvempunagar]

I've tried several developers with this film (4x5)... D-23 very diluted, POTA (acceptable), Pyrocat-HD (didn't like results), Caffenol (muddy). In the end, Adotech IV gave the best results.

I made the mistake of not buying Adotech developer along with CMS 20 ii rolls. Now it's too expensive to buy it separately. OTOH I had good results reversing the film with my own brew of developer albeit at a modest EI of 6. Maybe I should just continue with reversal processing than experimenting with Pyrocat or Caffenol.

 

[fs999]

I have used this film a lot at different Exposure Indices, including EI 6. And I cannot recommend Caffenol.

Did you try Caffenol CLCN (or LC+CNew) form Philippe May (in French) ?

 

[Henning Serger]

Did you try Caffenol CLCN (or LC+CNew) form Philippe May (in French) ?

No, but honestly I don't expect any other results.
I am running an independent photography test lab, and I have tested more than 40 different developers over all the years. And Caffenol fans have contacted me, praised their recipes, we've exchanged films, recipes and test results. But none of these Caffenol fans was ever able to offer a scientific test result, e.g. a proper characteristic curve. None of them used a densitometer. None of them was a darkroom printer. All were using scanning and manipulated their results in PP.
When I have tested their recipes, I have always found that their claims / statements of "how excellent their recipe is" simply were not true. The results have always been (much) worse compared to established developers. The characteristic curves could not compete with those of established developers. I am a darkroom printer. For me a film-developer combination has to deliver very good results as a solid base for optical enlargements / traditional darkroom printing.

Best regards,
Henning

 

[fs999]

No, but honestly I don't expect any other results.

I can assure you the results are the same as with Adotech. This Caffenol is far weaker than Caffenol CL !