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Mustafa Umut Sarac
06-20-2007, 09:32 PM
Photo Engineer , Do you know the secrets of kodachrome ? Can you post whatever you know about the greatest film ?

Best ,

Mustafa Umut Sarac

Photo Engineer
06-20-2007, 09:36 PM
There are none. That is the secret.

It is a set of B&W emulsions processed in a B&W first developer and 3 color developers. If the old color developers are used the old color gamut is attained, and if the new color developers are used, the new gamut is attained.

Nothing magic about it.

It can be done at home, and you can even duplicate it using tricolor exposures on TriX Pan and 3 color developers then laminating the film together.

No magic, just hard work.

PE

Pinholemaster
06-20-2007, 09:43 PM
Darn Photo Engineer you gave away the only 'secret' I know about Kodachrome.

Happy B&W shooting. Grin.

dmr
06-20-2007, 09:48 PM
I'm not a technogeek by any means, but a totally fascinating description of Kodachrome, and of Kodachrome K14 processing is in a set of documents describing the theory and operation of the K-Lab processor, the machine that does, or did K14 processing. I thought I had it bookmarked here, but apparently not. Google it. If you can't find it I may have it bookmarked on the machine at work.

Photo Engineer
06-20-2007, 10:02 PM
DMR;

There are the patents to read as well. I don't have the references here, but they give the entire process that can be used.

PE

AgX
06-20-2007, 10:24 PM
Mustafa,

The fascinating thing about Kodachrome (1st version) to me is that, after chromogenic development of all three layers with the same coupler, by sheer control of diffusing time of a dye-bleaching solution it could be achieved that one single layer was spared. Then doing it all over again…

Mustafa Umut Sarac
06-20-2007, 10:32 PM
Photo Engineer , Are patents from Kodak ? There are 7000000 patents at uspto and hundreds may be thousand of them using kodachrome term.
I think I am interested in 3 color developers. Can you write more and give us specific patent class least for this process. Or you can copy and paste from united states patent office lists as a reference ? There are zillions of chemicals and your eye can select them.
I want to do this at home and i need your guide.

Mustafa Umut Sarac
06-20-2007, 10:35 PM
Laminating ? I worked at a company which uses 4 color process proofer with heat lamination. I made hundreds of 2 meter long proofs. I think you are pointing this technology.

dmr
06-21-2007, 12:15 AM
There are the patents to read as well. I don't have the references here, but they give the entire process that can be used.


Actually, I have followed a couple of your previously posted patent links.

The problem with the patent docs is that you have to be a, well, uh, photo engineer to get the most out of them. :) I'm certainly not one. :)

Out of your posts and the on-line documents, I have however developed a strong appreciation for the precision that goes into creating the film and processing it with such stunning results.

I find the Kodachrome process fascinating. The precision at which the re-exposures are done without contaminating the other layers, the color developers, etc., all with very consistent results.

Now, from reading the notes on the coating workshops, and how difficult it is to get a single layer coating, B&W only, it just boggles my mind to look at how many layers there are in Kodachrome (or Ektachrome or C41) and the precision by which those must have to be applied for such consistent results.

Another thing that totally fascinates me (yeah, a bit off topic for this thread) is how the CD3/CD4 reacts to produce the correctly colored oxides or whatever the end result of the color development process is, and to have accurate and stable colors as well.

These are all above my head a bit, but I admit some awe and fascination with them. :)

dmr
06-21-2007, 12:30 AM
Sorry for monopolizing this thread, but here's the link I referred to earlier:

http://www.kodak.com/global/en/service/Zmanuals/z50.shtml

Part 3 is the one that goes into the nuts and bolts about Kodachrome and how the K14 process works.

One very fascinating thing is the description on how to salvage a customer's film during a malfunction using a "trouble bucket", but I don't know how successful that actually is.

Photo Engineer
06-21-2007, 10:06 AM
Photo Engineer , Are patents from Kodak ? There are 7000000 patents at uspto and hundreds may be thousand of them using kodachrome term.
I think I am interested in 3 color developers. Can you write more and give us specific patent class least for this process. Or you can copy and paste from united states patent office lists as a reference ? There are zillions of chemicals and your eye can select them.
I want to do this at home and i need your guide.

The entire process is given in a patent to Bent and Mowrey of Eastman Kodak. In this, the CD-6 developer is disclosed.

You will note that the patent has been abandoned (thereby donating it to the public).

PE

AgX
06-21-2007, 10:06 AM
Mustafa,

before you are going to follow the paths of Mannes and Godowsky, don't forget that you have a lot of image diffusion transfers to do...
I just did that post on Polaroid.

Photo Engineer
06-21-2007, 09:54 PM
Leadly and Stegmeyer disclose a method of making tricolor separations that can be combined into Kodachrome type transparencies.

PE

John Shriver
06-26-2007, 09:50 PM
US Patent 3,658,525.

Neanderman
06-27-2007, 11:40 PM
You will note that the patent has been abandoned (thereby donating it to the public).

PE

They abandoned this in 1975, a mere 3 years after its granting. So what didn't work in it? :-)

Photo Engineer
06-28-2007, 09:49 AM
It is fully implemented in the current Kodachrome process. I have no information on why it was abandoned. The patent was on the yellow layer color developing agent, CD-6. There were several patents on this developing agent.

PE

Craig
06-28-2007, 11:48 AM
They abandoned this in 1975, a mere 3 years after its granting.

There could be many reasons for abandoning a patent. In Kodak's case, it could be that they perceved a lack of competition, thus no need to keep the patent valid. Since they have the patent issued, no one else could patent it, so Kodak is free to use it as they see fit. All that changed is that they are no longer claiming a mononply on it.

Perhaps they didn't feel it was worth paying the maintenaince fees?

wirehead
06-28-2007, 03:19 PM
Maybe to avoid anti-trust difficulties?

Photo Engineer
06-28-2007, 04:41 PM
Craig;

The maintenance fees on all of the EK patents is a yearly killer in the budget, and so if there is no competition they will not maintain the patent. Since they decided not to use CD-6 in Ektachrome E6 nor in RA chemistry, it was therefore used only in Kodachrome. And, that is about the year that Fuji begain withdrawing from Kodachrome.

PE

Craig
06-28-2007, 04:59 PM
Craig;

The maintenance fees on all of the EK patents is a yearly killer in the budget, and so if there is no competition they will not maintain the patent.


That makes perfect sense, and is likely the reason for the patent being abandoned, as the first maintenaince fee is due at 3.5 years from issuance. The fees increase as the patent ages, so it would be logical for EK to review each patent for usefulness before paying the fees.