Kodachrome

about to extinct

D
about to extinct

  • 2
  • 0
  • 95
Fantasyland!

D
Fantasyland!

  • 9
  • 2
  • 132
perfect cirkel

D
perfect cirkel

  • 2
  • 1
  • 130

Recent Classifieds

Forum statistics

Threads
198,750
Messages
2,780,367
Members
99,697
Latest member
Fedia
Recent bookmarks
6
Status
Not open for further replies.

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
Cyan dyes are usually Napthol or Phenol derivatives. Magentas are usually Parazolone derivatives, and Yellows are usually Pivaloyl or Phenyl acetoyl derivatives. None of these form Azo dyes which are N=N dyes. These form Azo Methine dyes which are N=C dyes.

I don't know the CAS numbers.

PE
Thats fine thanks.
Looks like the couplers in the patent are definitely correct then.

The whole idea about Azo dyes was what I read in some blog about Kodachrome, supposedly claiming thats why Kodachrome was so archival.

I dont think there are any CAS numbers for the couplers. They would have been documented in the patents if so, and by the looks only Kodak, would likely have ever made these compounds.
 
Last edited:

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
I missed this somehow.

Pyrazolones are NEVER used as Cyan or Yellow couplers.

Only the Magenta is now. In years gone by it was another compound which gave very unstable dyes. Nowdays, color paper and some films use new classes of couplers.

Edited to correct very bad error.

PE
That seems to make sense. This would explain why the likes of old eastman movie stock fades to red, the magenta layer is so stable and everything else fades away.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
Just pushing the PH up, and running the devs all at 6 minutes.
That is really strange.

Would the PH have anything to do with it?
Is it possible that the magenta developer is ruining the other layers somehow?
 

piratelogy

Member
Joined
Sep 14, 2012
Messages
87
Format
Medium Format
That is really strange.

Would the PH have anything to do with it?
Is it possible that the magenta developer is ruining the other layers somehow?

I've no clue. I'm going to run another test using my non-PH formula just to be sure something hasn't gone off with my chemistry.
 

Gerald C Koch

Member
Joined
Jul 12, 2010
Messages
8,131
Location
Southern USA
Format
Multi Format
Thats fine thanks.
Looks like the couplers in the patent are definitely correct then.

The whole idea about Azo dyes was what I read in some blog about Kodachrome, supposedly claiming thats why Kodachrome was so archival.

I dont think there are any CAS numbers for the couplers. They would have been documented in the patents if so, and by the looks only Kodak, would likely have ever made these compounds.

A lot of work has gone into providing a CAS number for all known chemicals. So not in the original patent but they exist now. Unlike chemical names each CAS number is unique. CAS 123-30-8 can be called 4-aminophenol OR 4-hydroxyaniline plus a few more. There is most likely a naming convention saying a phenol derivative over an aniline one but it escapes me now.

A common blood pressure medication valsartan has the IUPAC name (S)-3-methyl-2-(N-{[2'-(2H-1,2,3,4-tetrazol-5-yl)biphenyl-4-yl]methyl}pentanamido)butanoic acid. Even fairly small molecules can be a challenge when it comes to names. So you can see the advantages of CAS numbers. BTW if you look at the structure cited below its synthesis was an organic synthesis tour de force.

http://www.chemspider.com/Chemical-Structure.54833.html
 
Last edited:

falotico

Member
Joined
Aug 31, 2012
Messages
265
Format
35mm
Thats fine thanks.
Looks like the couplers in the patent are definitely correct then.

The whole idea about Azo dyes was what I read in some blog about Kodachrome, supposedly claiming thats why Kodachrome was so archival.

I dont think there are any CAS numbers for the couplers. They would have been documented in the patents if so, and by the looks only Kodak, would likely have ever made these compounds.


Why don't you find out if anybody has any off-the-shelf couplers for yellow and magenta? Some of the expert discussion suggests that such couplers will be soluble enough for inclusion in the color development as Kodachrome development requires.

See what is available on the market. They probably are already prepared for stability.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
A lot of work has gone into providing a CAS number for all known chemicals. So not in the original patent but they exist now. Unlike chemical names each CAS number is unique. CAS 123-30-8 can be called 4-aminophenol OR 4-hydroxyaniline plus a few more. There is most likely a naming convention saying a phenol derivative over an aniline one but it escapes me now.

A common blood pressure medication valsartan has the IUPAC name (S)-3-methyl-2-(N-{[2'-(2H-1,2,3,4-tetrazol-5-yl)biphenyl-4-yl]methyl}pentanamido)butanoic acid. Even fairly small molecules can be a challenge when it comes to names. So you can see the advantages of CAS numbers. BTW if you look at the structure cited below its synthesis was an organic synthesis tour de force.

http://www.chemspider.com/Chemical-Structure.54833.html

OK, thats useful thanks.
I was unsure how that system works.
I see you can submit chemicals on chemspider, so some should be able to help there I expect.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
Why don't you find out if anybody has any off-the-shelf couplers for yellow and magenta? Some of the expert discussion suggests that such couplers will be soluble enough for inclusion in the color development as Kodachrome development requires.

See what is available on the market. They probably are already prepared for stability.

I have not been able to find anything myself, other than pretty much what piratelogy and Steve Frizza have already been using.
Ive provided links to some of them here.
Off the shelf, are to referring to the rockland Polytoner couplers?
 

falotico

Member
Joined
Aug 31, 2012
Messages
265
Format
35mm
Some of the chemical suppliers such as PubChem, Chemicalland21, Alfa Aesar, etc. will list compounds as "couplers". Using the search function and examining the structures presented might reveal some useful products. You could also search by the component chemistry, pyrazolones, naphthols, etc. and see if any useful compound turn up. It is a good way to learn coupler chemistry.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
Rockland couplers are quite useful for imaging in color.

PE
The question is whether those will work with Kodachrome or not though.

There was a thread where someone experimented with them, but with poor results.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
I knew that, I was trying to get NZoomed off his butt and quit giving advice and try to do something himself! :wink: :D

PE
Im sorry if im taken the wrong way on here, I dont want anyone to think im coming across as a know all, im not trying to be.

Anyway, i dont have the resources to attempt processing currently, let alone any spare Kodachrome! Im just trying to do my best to help.

As far as the polytone couplers go, how stable are they? Unless I was mistaken, I believe that you said the couplers quoted here were not very stable and could last, not sure if these were the polytone ones.

Anyway, im in the process of dealing with labs who can prepare the right couplers.
I am also getting in touch with the royal society of chemistry who should be able to assist in registering these chemicals with a CAS number.
 

piratelogy

Member
Joined
Sep 14, 2012
Messages
87
Format
Medium Format
Im sorry if im taken the wrong way on here, I dont want anyone to think im coming across as a know all, im not trying to be.

Anyway, i dont have the resources to attempt processing currently, let alone any spare Kodachrome! Im just trying to do my best to help.

As far as the polytone couplers go, how stable are they? Unless I was mistaken, I believe that you said the couplers quoted here were not very stable and could last, not sure if these were the polytone ones.

Anyway, im in the process of dealing with labs who can prepare the right couplers.
I am also getting in touch with the royal society of chemistry who should be able to assist in registering these chemicals with a CAS number.


The Polytoner ones are basically the same as the ones I've been using, though I'm ordering them separately. Cyan and yellow are the SAME couplers, and the magenta is very very close to the one I'm using.
As PE stated they're not going to be stable, I've not had any real longevity tests to tell you just HOW unstable they really are.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
Maybe you could stick one of the test strips under a bright heat lamp or something to test longevity?
I was thinking the same. Exposing under a UV lamp would be a good test, but thats not replicating ideal storage conditions, so I would keep stored in a hot place for extended periods, I know that heat speeds up the breakdown of dyes, and when frozen, it lasts forever.

If you freeze eastman film stock that is prone to going red, it will halt the progress, as well as stopping vinegar syndrome.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
The Polytoner ones are basically the same as the ones I've been using, though I'm ordering them separately. Cyan and yellow are the SAME couplers, and the magenta is very very close to the one I'm using.
As PE stated they're not going to be stable, I've not had any real longevity tests to tell you just HOW unstable they really are.
Yes, I agree.

Stability is not a big issue to me TBH, as long as the results are typical of what you would expect from Kodachrome, I would be happy enough and then I would scan them at high res.
Its more if people were wanting something archival that i can see the need for stable dyes.

I will keep everyone updated if I can get the chemicals sourced from China.
It appears from looking at the datasheets, that very little is actually needed when mixing a batch, so it should last a long time if I can get a small sample.

I will arrange to have the chemicals sent directly to you if they confirm they can do it.

I also hope to get in touch with Kelvin Kittle as it looks like he still has his K-lab and has been spending time on its restoration. Im unsure if its now operational, but he has not forgotten about it.

If he has it operational, i would like to see it that someone could help him and get the lab running with the right chemistry.
(I cant because i live in New Zealand) but I will do my best to help him and anyone else who wants to get the right couplers.
 

piratelogy

Member
Joined
Sep 14, 2012
Messages
87
Format
Medium Format
Yes, I agree.

Stability is not a big issue to me TBH, as long as the results are typical of what you would expect from Kodachrome, I would be happy enough and then I would scan them at high res.
Its more if people were wanting something archival that i can see the need for stable dyes.

I will keep everyone updated if I can get the chemicals sourced from China.
It appears from looking at the datasheets, that very little is actually needed when mixing a batch, so it should last a long time if I can get a small sample.

I will arrange to have the chemicals sent directly to you if they confirm they can do it.

I also hope to get in touch with Kelvin Kittle as it looks like he still has his K-lab and has been spending time on its restoration. Im unsure if its now operational, but he has not forgotten about it.

If he has it operational, i would like to see it that someone could help him and get the lab running with the right chemistry.
(I cant because i live in New Zealand) but I will do my best to help him and anyone else who wants to get the right couplers.

I wasn't aware that any of the K labs were still in existence, that'd be awesome to get the chemistry to the point we could help him get it up and running again.
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
I wasn't aware that any of the K labs were still in existence, that'd be awesome to get the chemistry to the point we could help him get it up and running again.

A working K-Lab would be the ultimate solution, but would have to be modified to handle super8 and 16mm, I dont know whats involved, but may need different rollers etc, may not be that straightforward, I can see alot of potential issues, mainly with the remjet remover and re-exposure lamps.

Check out the facebook page for the space shuttle film.
https://www.facebook.com/pages/Space-Shuttle-Film/156663554369586
He is still very much active on there and said he has been working with the k-lab owner (kelvin kittle) who bought the old K-Lab from the rocky mountain film lab.

Im looking forward to hearing back from him and hopefully we will get an update on the K-Lab status.
 
Last edited:

Photo Engineer

Subscriber
Joined
Apr 19, 2005
Messages
29,018
Location
Rochester, NY
Format
Multi Format
AFAIK, all of the chemicals involved in Kodachrome production had CAS numbers. They are just hard to come by.

Many chemicals can form dye with oxidized color developers. It is mainly a matter of hue and stability.

PE
 

Nzoomed

Member
Joined
Mar 30, 2012
Messages
1,259
Format
35mm
AFAIK, all of the chemicals involved in Kodachrome production had CAS numbers. They are just hard to come by.

Many chemicals can form dye with oxidized color developers. It is mainly a matter of hue and stability.

PE

Yes, thats my main reason for trying to source the correct couplers if we are truly trying to replicate the K14 process, or else that kodachrome "look" may not be the same as expected, especially for the reds.

I know there are many other couplers out there, but we may as well do it right the first time, but at least in the mean time, a wealth of information is being collected by those experimenting with the process, so I commend piratelogy's efforts.

As far as CAS numbers go, they should be on the database here at http://www.cas.org/
I think its only possible to search by the CAS number though, rather than the chemical name itself.

I might be able to ask them to give me a list of everything Kodak has submitted to them, but I expect that will be a very long list!
 
Status
Not open for further replies.
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom