Adox CMS 20 Slides, what bleaching chem ???

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Originally Posted by Pere Casals

Thanks for the The Photostudio13 information... I'll consider to have a benchmark, anyway I'm interested in developing it myself.

I also tried with PQ Universal, it is in the reversal recipe from Ilford.

As first developer I used Adotech II, consider that CMS is microfilm and it renders extreme contrast as it is monodisperse, so all grains are of similar size so there is no natural tone gradation, a low contrast developer is needed !

After stop bath I open lights (as it can be done and I do with any reversal) and see metallic silver and silver halide, it is correct because if I fix it I obtain a normal negative, but if I apply bleach (permanganate or dichromate) metallic silver goes away but halide also does, when it should stay.

I'd like to see that example please, if possible, to know what results can be obtained !!

Thanks in advance

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Read Thomas' link carefully with the discussion we had about reversal processing...

I'm wondering if the emulsion of CMS might be too thin for reversal processing??? (Old school thicker emulsion films tend to work better...)

Steve K

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Originally Posted by interneg

The first developer from a 6-bath E6 .

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Perhaps, I ask... can the first developer of a 3 bath E-6 kit also work?

Tetenal Colortec E-6: "The film reversal takes place during the colour development. Bleaching and fixing are in a combined bleach fixer",

So first developer bath of the 6-Bath may be equivalent to the 3 bath kit one, as both are only silver developers... (I've Colortec in the shelf...)

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Originally Posted by interneg

You should also look into what Ron Mowrey (Photo Engineer) says in these posts about reversal processing

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Thanks for the links, good information, I'll read it twice.

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Originally Posted by LabRat

I'm wondering if the emulsion of CMS might be too thin for reversal processing??? (Old school thicker emulsion films tend to work better...)

Steve K

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Yes, it's very thin, anyway it is done by a copule of labs with "scala process" with impressive results.

CMS grains are very small, ISO 3 or 6 tipical, (even it is shot at ISO 12 or 20) so they have a large surface vs mass relationship, any harm a bleach bath do to halide chrystals if multiplied by a big factor when reversing CMS 20 microfilm material, compared to common pictorial films... what can be tolerated for other films destroys CMS 20, even fixing more than 30 seconds may destroy highlights.


I'll read again Thomas' link, thanx

Regards
Pere

It might be worth looking back to reversal processes intended for Tech Pan; there are similarities between that film and the document films that are the basis of CMS 20, including the use of very low contrast process for negatives. Kodak used to sell a reversal kit intended specifically for Tech Pan, but there were also a number of "off the shelf" processes, including use of self-fogging second developers for either black or sepia image (the latter was approximately use sepia toner). Key in all of these was the first developer, but I don't recall details of the process (it's been close to thirty years since I read up on it).

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Originally Posted by Donald Qualls

It might be worth looking back to reversal processes intended for Tech Pan; there are similarities between that film and the document films that are the basis of CMS 20, including the use of very low contrast process for negatives. Kodak used to sell a reversal kit intended specifically for Tech Pan, but there were also a number of "off the shelf" processes, including use of self-fogging second developers for either black or sepia image (the latter was approximately use sepia toner). Key in all of these was the first developer, but I don't recall details of the process (it's been close to thirty years since I read up on it).

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Thanks for the clue Donald,

I've searched and I found a Tech Pan process: http://www.tech-diy.com/reversal_formulas.htm

I found this formula for the Dichromate bleach bath:

Bleach: Add to 1 litre water 9.5 g Potassium Dichromate and 66g Sodium Bisulfate and stir until dissolved.


This is different from the general DW-1 of the Cookbook I was using

DW-1
Bleach Bath
(David Wood)
Potassium bichromate (Dichromate), anhydrous, 6.0 g
Water to make 1.0 liter
Sulfuric acid, concentrate, 12.0 ml


I'll try it. Thanks again.


Regards,

Pere Casals

Pere, if you don't have yet enough ideas, take a look at the Ian Grant's post in APUG for some more thoughts.

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Originally Posted by Domingo A. Siliceo

Pere, if you don't have yet enough ideas, take a look at the Ian Grant's post in APUG for some more thoughts.

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Many thanks, following your link I found this interesting video:

https://www.youtube.com/watch?v=OvGCaZy_kUY

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Originally Posted by Domingo A. Siliceo

Pere, if you don't have yet enough ideas, take a look at the Ian Grant's post in APUG for some more thoughts.

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I'd also add a couple of other things I've just remembered - it's a bad idea to use a thiocyanate containing developer with a permanganate bleach (risk of liberating cyanide) - thus why Kodak changed D94 (which contains thiocyanate) to D94a (which uses D-TOD) when they went from R9 (dichromate) to R10 (permanganate) bleach. You should read http://www.apug.org/forum/index.php?...-bleach.65708/ as it goes over the potential dangers of thiocyanates & permanganates mixing.

Kodak do offer a Motion Picture BW reversal development kit -http://motion.kodak.com/US/en/motion...ls/default.htm with the above developers & bleaches, however it is designed to make 15 US gallons.

http://www.apug.org/forum/index.php?...ure-film.5653/ has the formula for D94a

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Originally Posted by interneg

I'd also add a couple of other things I've just remembered - it's a bad idea to use a thiocyanate containing developer with a permanganate bleach (risk of liberating cyanide) - thus why Kodak changed D94 (which contains thiocyanate) to D94a (which uses D-TOD) when they went from R9 (dichromate) to R10 (permanganate) bleach. You should read http://www.apug.org/forum/index.php?...-bleach.65708/ as it goes over the potential dangers of thiocyanates & permanganates mixing.

Kodak do offer a Motion Picture BW reversal development kit -http://motion.kodak.com/US/en/motion...ls/default.htm with the above developers & bleaches, however it is designed to make 15 US gallons.

http://www.apug.org/forum/index.php?...ure-film.5653/ has the formula for D94a

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Many thanks for the links, I'm to use dichromate as bleach, taking necessary care (and end mixing used developer to reduce chrome later...) instead thiocyanate I'm to use tiosulfate at first.

Thanks to cinematographers we still have this asset as a benchmark, but the 15 gallons...

I'm to read those links, thanks again

Hi,
I'm new here. Could you please let me know if you have any good results with Adox CMS 20 II?

I developed a couple of slides in Ilford PQ Universal 1+5 with 8g hypo 1 min 45 sec as longer development removes emulsion. Anyhow, a colour of developer changed to slightly black, which was not a good sign as it should be slightly green, and it turned out that emulsion started removing (even at 1 min. 45 sec) but insignificantly. For bleaching (around 45 sec) I use potassium bichromate 10 g with sulfuric acid (conc.) 10 ml per 1l of water.