Adox CMS 20II in pota

mard0 · Feb 12, 2019

During the coming weeks I will be shooting my first roll of Adox CMS 20II. There is a lot of information on the web about how to develop this film, but somehow there is almost no information about developing it in pota.

Has anybody tried adox CMS 20II in pota? Is it possible to produce negatives with normal contrast with this combination?

Andrew O'Neill · Feb 12, 2019

I have a hunch that that'll be a good combination. I used Pota with Tech Pan, and got lovely results.

mard0 · Feb 12, 2019

Andrew O'Neill said:
I have a hunch that that'll be a good combination. I used Pota with Tech Pan, and got lovely results.

Nevertheless, I could only find 2 mentions of this combination. And the 2 mentions do not seem to agree on an EI or developing time.

Pioneer · Feb 12, 2019

It has been a very long time since I mixed up any pota but I would think that exposing the film at EI-12 and developing for 10 minutes at about 75F would make a great starting point.

I may source some phenidone from Photo Formulary and give this a try myself. Might be fun.

Rudeofus · Feb 12, 2019

A while back our member michael_r posted vastly improved versions of POTA, most notably one which maintained extremely controlled contrast yet kept full speed. Especially the HQ version seems to be easy to mix, and it is made from very easy to get ingredients. Since ISO 20 is already very slow, it may be well worth going through the extra effort.

Pioneer · Feb 12, 2019

Interesting thread Rudeofus. I learned quite a bit about low contrast developers that I was totally unaware of.

Unfortunately it didn't look like much work was done to apply this information to Adox CMSII type document films. From what I could determine most of the work was aimed at developing a low contrast developer for films like TMX, TMY2 and perhaps a couple of others usable under certain circumstances where N- development was needed. This could certainly be applicable to document films since its' normal high contrast requires quite a bit of taming. But I think it would still take quite a bit of testing to get there.

All great information. I will personally keep the work done by MichaelR in mind as the formula(s) mentioned may provide a much less expensive alternative to the recommended Adotech developers. For myself I am more inclined to begin with the standard POTA formula just to see if it can even get close to what Adotech IV already provides in the way of image quality. I am not too sure about that but only a trial will tell.

I have a few rolls of Adox CMS II and I have ordered up a bit of Phenidone so I guess I will see what happens. The cost of 10 grams, including Hazard Shipping, is about the same as one bottle of Adotech IV. I can develop 5 rolls of CMS II with the Adotech IV where it looks like I'll be able to get at least 10 rolls, maybe a bit more, developed with the 10 grams of Phenidone (Sulfite I have plenty of.) If it works I'll be thrilled and I will order up a larger quantity of Phenidone. If it doesn't I won't be out much but a few dollars, a lot of time spent stirring, and a few rolls of film.

I will be back as things develop...

Andrew O'Neill · Feb 12, 2019

mard0 said:
Nevertheless, I could only find 2 mentions of this combination. And the 2 mentions do not seem to agree on an EI or developing time.

You'll have to strike out on your own then.

mard0 · Feb 13, 2019

Pioneer said:
I would think that exposing the film at EI-12 and developing for 10 minutes at about 75F would make a great starting point

Great, this was roughly what I had intended as a starting point.

Rudeofus said:
Since ISO 20 is already very slow, it may be well worth going through the extra effort.

ISO 20 is already to slow for handheld photography this time of year. So I was thinking about using this film for some studio macro photography, most likely trying to balance flash and ambient light. A stop more or less is thus not really an issue, I will just need to keep shutter open for a longer time.

Pioneer said:
Interesting thread Rudeofus. I learned quite a bit about low contrast developers that I was totally unaware of.

Indeed a very interesting post. For now, I've only skimmed it. But I have saved it for a more in-depth read later.

Andrew O'Neill said:
You'll have to strike out on your own then.

That's always the case when trying out a new flim + developer combination. You will have to find an EI and developing routine that fits your style of metering and printing. But its nice to have a starting point to base your work on. And to know if its even worth trying the combination.

Rudeofus · Feb 13, 2019

mard0 said:
ISO 20 is already to slow for handheld photography this time of year. So I was thinking about using this film for some studio macro photography, most likely trying to balance flash and ambient light. A stop more or less is thus not really an issue, I will just need to keep shutter open for a longer time.

Have you checked reciprocity characteristics of this film? Once your exposure times grow into the seconds range, you will not only have to extend exposure time, it will also increase contrast (strongly exposed regions see less Schwarzschild effect than weakly exposed ones).

mard0 · Feb 13, 2019

Rudeofus said:
Have you checked reciprocity characteristics of this film? Once your exposure times grow into the seconds range, you will not only have to extend exposure time, it will also increase contrast (strongly exposed regions see less Schwarzschild effect than weakly exposed ones).

No, I had not yet looked into this. Fortunately I have more than enough flash power and diffusers to rely on flash only. A mixture of ambient light and flash does of course have a more natural look, so I will have to look into the reciprocity failure and see how far I can push it.

Pioneer · Feb 13, 2019

mard0 said:
No, I had not yet looked into this. Fortunately I have more than enough flash power and diffusers to rely on flash only. A mixture of ambient light and flash does of course have a more natural look, so I will have to look into the reciprocity failure and see how far I can push it.

Let us know how this turns out for you. Right now PhotoFormulary has my Phenidone on back order for an undetermined period of time so I may not be able to get to this for a little bit.

Just a question. Have you tried Adotech IV yet? Though it is a bit expensive you may want to at least invest a little bit in that developer as you will get a sense of what is possible with the recommended developer before you actually dive into experimentation.

Just a thought.

mard0 · Feb 15, 2019

I have yet to find some time to do the first tests. The first roll will likely be sacrificed for a EI test, then some short pieces to fine tune the developing. I will then test the reciprocity for the ambient light exposure in combination with a flash exposure should there be some frames left on the roll.

Adotech IV was on back order at the web shop were I usually buy my film and chemistry. Not wanting to wait for it to arrive made me want to give pota a try.

mard0 · Feb 18, 2019

I've done a first quick EI test using my favourite test subject 200m from my house.

I used the spotmeter in my cabin T90 and placed the off-white pillar at +1,5. This gave me a shutter speed of 1/20, 1/15, 1/10 and 1/8 for EI 20, 16, 12 and 10 at f5.6.

The film was developed in pota 1+0 for 10 minutes at 20 degrees Celsius with constant agitation in a jobo.

Either EI 10 or 12 seem to be okay, looking at the detail in the lampposts on the right side of the image. But the developing time was a bit to long.

My next tests will be done using flash, since this is my intended lighting setup. The next step would be to cut down developing time for 1 or 1,5 minutes and make some test prints on grade 2 to better judge the contrast.

Rudeofus · Feb 18, 2019

Am I correct in my assumption, that the left most image was shot with the longest exposure time of 1/8 second (EI 10) ? Otherwise yes, sample pics look great!

mard0 · Feb 18, 2019

Rudeofus said:
Am I correct in my assumption, that the left most image was shot with the longest exposure time of 1/8 second (EI 10) ? Otherwise yes, sample pics look great!

No, the other way around. I must admit that it is quit hard to judge the negatives based on this image. I only had a light table and a smartphone at hand. I can scan the negatives without inverting them if you like, but I personally like a test print better when it comes to judging contrast and shadow detail. I don't trust my scanner to give an accurate representation of a negative.

Rudeofus · Feb 18, 2019

That scanner should at least give an impression where the sky is rendered darker in the negative - and the left most neg has bar far the highest density in the sky region. We are looking at negatives here, yes ?

mard0 · Feb 18, 2019

I don't have the negatives here with me, but I think that the differences in the sky are due to reflection of a light source on the negatives, or due to some other anomaly while taking the photo. It is really not a very good photo of the negatives (the frame numbers are also darker on the left compared to those on the right).

The difference in density is clearer in the pavement. I will try and post a better image of the negatives this evening.

Pioneer · Feb 18, 2019

From what I can tell from these negatives pota seems to be a very viable solution for developing this film.

Thanks, looking forward to more information.

Andrew O'Neill · Feb 18, 2019

Pota is a great developer for taming high contrast as well as high contrast films.

Pioneer · Feb 24, 2019

POTA is sure a pita.

My backordered Phenidone arrived this weekend so I mixed up a small batch of POTA and souped my Adox CMS II in it. It worked and I have negatives to print but mixing the phenidone into solution was a major pain in the neck. It certainly does not like to dissolve into solution. I must be doing something wrong because even after 15 minutes of constant stirring I still had undissolved solids from the Phenidone.

I developed at 77F for 11m agitating for the first 45 seconds and then three times per minute following that. From the looks of the negatives I have plenty of contrast so I may end up having to tone down the number of agitations and/or the solution temperature.

Rudeofus · Feb 24, 2019

The most popular way of getting Phenidone into solution is dissolving it in Propylene Glycol first. It lasts forever in such a solution.

PS: I am quite surprised you get high contrast with a POTA type developer. Phenidone is a terrible developer unless you have a secondary development agent in there. Any chance that CMS II has embedded HQ/Catechol/... as stabilizer or something like that?

Pioneer · Feb 24, 2019

Rudeofus said:
The most popular way of getting Phenidone into solution is dissolving it in Propylene Glycol first. It lasts forever in such a solution.

PS: I am quite surprised you get high contrast with a POTA type developer. Phenidone is a terrible developer unless you have a secondary development agent in there. Any chance that CMS II has embedded HQ/Catechol/... as stabilizer or something like that?

Guess I'll have to locate some propylene glycol then. Trying to stir this stuff into solution and then use it within an hour was a challenge.

As for high contrast that was only a guess from my first look at the negatives. I have always been terrible at reading my negatives, especially right out of the soup, and I won't really have a chance to print anything off of these until Tuesday or Wednesday. Truthfully I wont really know anything for sure until then.

EDIT - Besides, if anything can get screwed up in developing I'm the guy who can do it.

If CMS II does have any embedded secondary developer I've never heard of it.

devecchi · Feb 24, 2019

Rudeofus said:
The most popular way of getting Phenidone into solution is dissolving it in Propylene Glycol first. It lasts forever in such a solution.

PS: I am quite surprised you get high contrast with a POTA type developer. Phenidone is a terrible developer unless you have a secondary development agent in there. Any chance that CMS II has embedded HQ/Catechol/... as stabilizer or something like that?

To prepare a 5% solution of phenidone that temperature must be the propylene glycol?

Athiril · Feb 24, 2019

I didn't have good results.

The absolute best results I've had with CMS20 was with one of the two Perfection XR-1 recipes floating online, that was excellent.

Rudeofus · Feb 25, 2019

devecchi said:
To prepare a 5% solution of phenidone that temperature must be the propylene glycol?

Depends on whether you are in a big hurry. I was able to dissolve that amount at room temperature and it took less than a week as far as I remember. Since the concentrate in PG has very long shelf life, it's no problem to prepare it in advance.

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