I would be careful about this page or the MSDS data.
The first 6 yellow developers listed used CD-4 and the 7th used CD-6 so something is wrong with the list somehow.
PE
Yes.Kodachrome home processing would of course require some experimentation on exposed b & w film, which CD would work best ;-)
Another question in regard to the original patent: already the Ektachrome E-4 process had replaced reversal light exposure by chemical fogging with tert-butylaminoborane; the K-14 patent gives borohydride as the reagent. Now the first is said to be quite toxic, and has been replaced in E-6 by borohydride, but the latter may generate explosive hydrogen upon decomposition or accidentaly with acids, so that both compounds may not be available to the darkroom amateur.
Would it make sense to expose the cyan- and yellow-processed film with broad-spectrum white light to achieve the reversal exposure for the magenta development? For a (hypothetical) micro-K-Lab, red, blue, and green or white LEDs might provide suitable light sources for the dedicated reversal exposures.
Some additional notes here:
1. It is illegal to make a false or misleading statement in a patent. You can paint with a broad or narrow brush describing the invention, but it must be correct. It must work for all cases described as well.
2. APS was a combined attempt of Kodak, Fuji and Agfa to develop a new format identical in size to the then-common digital image sensors, [...]
[...] And, this leads me to the next answer. It is illegal to give false or misleading statements, but [...]
There always is such a "but". Or a proviso as the ones quoted.
Which makes it very hard to do something illegal, like giving false information, in a patent. Doesn't mean that they contain correct information.
It's all about business, making money. About protecting your ideas, your investment, your market opportunities.
Taking my comment out of context is rather a low blow.
I said that typos can take place and the patent was filed while work was still going on leaving room for changes. You can see that in the fact that the final film used the new hardener instead of the old one and allows for a higher process temperature without a prehardening step.
Ethical business practices, a course we were required to take at Kodak upon joining the company, gave us a good view of just the thing you infer always happens.
As it is, I wrote that patent personally from the lab notebooks and data of the individuals who worked with us. I was in the lab and worked with the technicians. However, since it was over 30 years ago, I don't remember the details and no work was done on Kodachrome since the early 80s.
Therefore it is easy for you to be an armchair critic and beat up on patents, but I would say that the phrase that is more operation is this one....
The patent must be sufficiently clear that it can be replicated by one skilled in the art. I am and therefore I could replicate it from the ground up!
Can you?
PE
You may be confusing [...]
...What should also not be forgotten about patents is that they very rarely contain correct detailed descriptions of how things are done.
They are not meant to allow other companies to have a look in, but quite the opposite: to shut other companies out. So (apart from describing in length why the claims made are not already "prior art") they more often than not paint the broadest possible picture of the genius of a certain idea (mentioning every imaginable way an idea could be applied), while deliberately providing incorrect details.
Or in other words: patents are part of business tactics. Not scientific or historic documents...
You might have a point here. However, a patent is, under legal theory, a "teaching" document. To be valid a patent must be "enabling" which means that to be valid a patent must teach enough about the invention to enable someone skilled in the art to reproduce the invention. If a patent is deliberately misleading or incomplete then it can be challanged and the courts may rule that it is "unenforceable."
Furthermore, a patent is supposed to also teach the best way to do the invention described in the patent. There have, in fact, been patents that have been declared unenforceable because they did not teach the best way to do the invention. Of course, this would mean the best way to do the invention as understood by the inventors at the time of the writing of the patent.
Photo Engineer said:If I posted an entire workable formula for Kodachrome with an ISO of about 25, would anyone make it? It cannot be hand coated except by a very good lab worker, but it can be machine coated with the aid of a coating engineer.
So, that would be a powerful question to have answered! I don't see anyone building their own coating machine nor anyone truly anxious to invest time and money in developing the film and process. It can be done, and I could probably post a set of workable formulas.
I would bet that no one would take me up on that.
The structure is /UV overcoat/Yellow/IL with yellow filter/Magenta/IL/Cyan/Support/RemJet backing The IL (Inter Layer contains 3-Sulfo-2,5 di-t-butyl Hydroquinone to prevent crosstalk. The yellow filter is colloidal silver. The rem-jet can be replaced with an antihal layer under the cyan layer which would be made of Gray colloidal silver.
I have no suggestions for the UV absorbing dye. It is essential though. The work would start by building a set of single layer coatings that showed feasibility, and then triple coats would be made (M + IL + C) for example, to show two color resolution and no crosstalk and finally assembly of the multilayer package to give full color photos.
PE
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